Perovskites are lately in the position of needing to prove longevity, which takes a long time.
In the meantime, they are quite a lot cheaper to make, so in many uses it would not matter so much if they did fail faster. In some uses, like aerospace, their lighter weight and better areal efficiency are essential, and forgive a lot.
> they are quite a lot cheaper to make, so in many uses it would not matter so much if they did fail faster
Hard disagree on that, their current longevity is comparably tiny so you'll have lots of overhead in installation costs. Not to mention the amounts of toxic lead trash you'll need to pay to dispose of, the thing is basically poison after all.
Makes far more sense to invest in multilayer tech even if it costs more since it'll last longer by an order of magnitude and use far less area to function which is a big benefit for vehicles too.
seems like for places where you could use silicon, but are limited by space and need high output then thy hybrids from Oxford PV seems ready, but I'd guess that's going to be a tiny share compared with people who just want it cheap and at scale.
Yale360 seems to cover renewables issues as if the reader already has some very weird ideas about them. Probably a sensible and sadly necessary approach.
But in reality, land use has never been a problem for Solar. It's great that lots of people are working on the issue and improving it. Just as lots of people are working on making them cheaper, or more environmentally friendly or easier to finance or a thousand other metrics.
But none of those were ever fundamental problems with the tech. Their own source of data about the 'problem' puts Ground-based PV at about the same land use as Coal.
They also missed out 'floatovoltaics' (PV on water) and building integrated PV as well as solar PV as a paving solution. Probably all of which are likely to be bigger than ground mount PV, given the trend to bifacial panels.
Deserts are hot and dusty. Efficiency falls quickly as temperature rises, and more as dust accumulates. Panels degrade exponentially faster as peak temperature increases. (Precisely: each fixed increase in temperature doubles rate of degradation.)
Siting panels on water and on farmland reduces operating temperature. Mounting vertically, in fence-rows, keeps off dust, collects more during morning and afternoon demand peaks, aids convective cooling, and protects crops from harshest afternoon sun.
"Same land use as coal" isn't necessarily an equivalent metric. Solar might be taking up land that could otherwise be used for food, for instance.
Better energy density will also help locate solar power closer to where it will be used, like on top of buildings in the city rather than in a large plant out in the middle of nowhere, thus saving on transmission costs.
Finally, IMO photovoltaic pavement is probably going nowhere.
Did everyone always know that solar/crop dual use was often purely beneficial for both? No. Did somebody know? Yes. Does everyone know today? Evidently not.
> Did everyone always know that solar/crop dual use was often purely beneficial for both? (emphasis added)
"Often" != "Always". Therefore you also agree that solar still competes for land use with crops.
Furthermore, land that has already been allocated to grid scale solar has already been taken away from possible crop use. Sometimes it's not arable land, but that isn't always the case, therefore solar is still ostensibly taking up land that could be used for crops.
Finally, I even disagree that somebody knew that solar and farming could use the same land. Someone had an idea that maybe they could coexist, then ran an experiment that succeeded. They certainly didn't know the outcome beforehand.
> Therefore you also agree that solar still competes for land use with crops.
No. It just means that some places are better than others.
Since there is overwhelmingly more crop and pasture land than could ever be needed to satisfy power needs, solar may be placed exactly and only where it does the most good.
It has been known for centuries that most plants benefit from partial shade. It is an exceedingly tiny step of logic to go from "shade" to "shade provided by solar panels". In the past, providing shade just cost money. Now it yields direct revenue, year-round.
> It has been known for centuries that most plants benefit from partial shade.
Again, "most plants" does not necessarily include "crops", most of which have been selectively bred over millennia while grown under full sun. The step is not from "plants do well under shade" to "plants do well under solar panels", it's to "crops we've never grown in partial shade might actually do better in partial shade too".
That's because it's such a non issue that the cost of thinking about it for a little bit exceeds the downsides.
When it is an issue there are countless solutions from sharing with livestock (already done in some areas) to providing partial shade for non energy crops like lettuce or capcicum that increase yield to covering parking.
For reference, there are about 2.5 billion parking spaces in the usa which take 20-50m^2 each, very little of which is more than three stories deep. This is room for between 1 and 5 TW of net (ie. averaged over the year including nights) capacity or roughly the USA's entire energy consumption. You could also replace a small fraction (about 5%) of corn used for ethanol (not the total corn) and get a similar result.
Solar might also provide better shade for livestock and cropping growth, particularly in future days of greater heat.
> Sheep grazing under solar panels at farms in NSW's Central West have produced better wool and more of it in the four years since the projects began, according to growers.
> Local graziers have labelled the set-up a "complete win-win", with the sheep helping to keep grass and weeds down so as not to obscure the panels.
This is not something that works so well with open cut coal and down wind from city supplying coal burning power stations.
Not sure why you're getting downvoted.
I think "floatovoltaics" are definitely a growth option with lots of upside - especially if located on man-made bodies of water e.g. dammed lakes (which often will have sufficient infrastructure already in place).
> Ground-based solar is land-intensive, however, with utility-scale arrays often spanning hundreds of acres. Wind farms have their own sprawling land needs.
This is stupid. The article leads with the solution to this non-problem. There is no shortage of pasturage to site solar in. Likewise, of reservoirs and canals. Both places get net benefit from the dual use, even discounting the extra revenue.
It is true, that the amount of solar needed to power the entire US is about 0.5% of the land.
That doesn't mean there's no benefit in increasing the efficiency of panels and get dual use of the land. It also has the benefit of allowing for solar in more places where it's needed for more decentralized power.
On the question of this being stupid or not, I think that a sentence saying "Ground-based solar is land-intensive, however, with utility-scale arrays often spanning hundreds of acres. Wind farms have their own sprawling land needs" that links to a source that says:
> Solar energy is one example where the context and type of material matter a lot. Solar panels made from cadmium use less energy and materials than silicon panels, and therefore use less land per unit. It also matters a lot whether you mount these panels on rooftops or on the ground. Rooftop solar obviously needs much less additional land; we’re just using space that is already occupied, on top of existing buildings. However, they do need some land over their life-cycle because they still require mining of the materials to make them, as well as the energy (mostly electricity) used in refining the silicon. Finally, the density and spacing of the panels also makes a difference.
> Wind is the most obvious electricity source that we should consider differently when it comes to land use. You find it separated from the other sources, at the bottom of the chart.3 There are several reasons for this. First, offshore wind takes up space, but it’s marine, not land area. Second, onshore wind is different from other electricity sources because you can use the land between turbines for other activities, such as farming. This is not the case for a coal, gas or nuclear plant. This means the land use of wind farms is highly variable. I have calculated the land use of 22 of the world’s largest wind farms [you find my calculations here].
> Take the Roscoe Wind Farm in Texas, which uses 184 m2 per MWh. This is a large project, where farmers can generate additional income through electricity production while they continue their farming operations between the wind turbines. The wind farm is almost a secondary land use. This contrasts with much more dense wind farms, such as Fântânele-Cogealac in Romania, or the Tehachapi Pass in California, where energy production is the primary land use. These can have a small land footprint of just 8 m2 per MWh.
Seems pretty stupid to me. Though if someone get sucked in by the headline, reads the article and moves from thinking "we don't have enough room for renewables" to "there are lots of ways to dual use land with renewables" then maybe it's all for the best.
>"Indeed, laws of physics are identical in all countries."
There's no need to be glib, and the GP was obviously talking about the availability of land on a much smaller and more densely populated nation than the comparatively massive and wide open country that is the United States.
You also seem to be ignoring cost and land value. Just because land seems to be available doesn't mean it actually is. Or that it would be economical to convert it. And I also wonder how a solar panel, which blocks sunlight, would allow crops/grass to grow underneath it at the same time.
It seems like trying to make land do these two sunlight dependent things at once is not as efficient as having dedicated agricultural fields and dedicated solar farms.
>"Please allow me to suggest you consult some actual, you know, facts."
You're free to provide them. Call it concern-trolling if you'd like, but I definitely sense you've got a "why don't we just" mindset, where any potential downside is literally a non-issue. You dismiss all concerns and then wonder why something isn't being done when the solution looks so simple.
>"Since solar may use up exactly zero acres, its watts per acre may be infinite."
If it has mass and surface area, it will take up some sort of acreage. Solar panels block light, so obviously anything needing light to survive is going to struggle being underneath them. And, who knew that we could get an infinite amount of wattage out of zero acreage, why haven't those fools designing our electric grid realized this yet?!?
>"But most crops do not, and benefit both from reduced heat stress and reduced water loss."
So you've acknowledged that corn and wheat need full sunlight, but again, it doesn't matter, because in your view solar has no downsides whatsoever. Anything bad is actually good!
Corn and wheat do not, in fact, "need" full sunlight. They have slightly reduced yield in partial sun. That is offset against year-round revenue from power generation, a net positive, most places.
You were free to read any of the numerous links provided both in TFA and in comments posted here. Instead, you trolled.
It wouldn't be pasture if it were covered in solar panels. Isn't that what the article is saying, place solar panels sparse enough that you get pasture and panels.
Personally I think they should be put to sea. Along with floating farmland. Just make concrete (or seacrete!) pontoons, connected together into 1000 km^2 islands. Leave the actual land to nature. I concede that is currently scifi though.
Maybe you could take your own remark as a clue that dual-use does not "cover" every square centimeter with panels.
When you recognize you have plenty of land that is not being used up by placing panels in it, you can understand there is no need to try to pack panels as closely together as conceivably possible. You can leave room between for livestock and grass.
Open ocean has destructive waves. Panels do much better on calm reservoirs and ponds.
What's your basis for this? Real-world power grids don't seem to be designed around transmission loss being a non-issue so long as they just 'generate more power' at the source.
I think most real world grids are (or at least were) actually designed like this.
Getting coal from a mine to a power station is a big task, so some grids are literally built around the locations of the coal. Hydro and nuclear have similar location needs.
This has changed more recently with gas and renewables where as they get cheaper other factors start to dominate, but the grid was not originally set up for that kind of distributed load and needed some tweaks to adjust I believe.
Power at the source has never been as cheap as solar, and has always consumed extra operating expense to generate. Solar does not cost more each day it produces; you put up more panels and you get more power, day after day.
> Although land acquisition poses challenges, land availability does not constrain solar deployment in the scenarios.
> In 2050, ground-based solar technologies require a maximum land area equivalent to 0.5% of the contiguous U.S. surface area, which could be met in numerous ways including use of disturbed or contaminated lands unsuitable for other uses. The maximum solar land area required is equivalent to less than 10% of potentially suitable disturbed lands, avoiding conflicts with high-value lands in current use.
> Various approaches are available to mitigate local impacts or even enhance the value of land that hosts solar systems. Installing photovoltaic (PV) systems on water bodies, in farming or grazing areas, and in ways that enhance pollinator habitats are potential ways to enhance solar energy production while providing benefits such as lower water evaporation rates and higher agricultural yields.
> Expanding rooftop PV could reduce solar land use. Almost 200 GW of rooftop PV are deployed in the decarbonization scenarios by 2050 (10%–20% of total solar deployment). However, the technical potential for U.S. rooftop PV is greater than 1,000 GW, and efforts to promote rooftop PV could increase deployment beyond the modeled level.
At least in the US if you look at all of the long distance transmission lines, you could easily find huge areas next to the lines that are totally uninhabited to site a new solar installation plus the transformers etc to connect up to the grid there. The same helicopters they use to service the lines could likely be used to blow off the solar panels once a month when they get dust on them. Somebody should totally do a study of saying "ok here is one major transmission line going across Texas from this big power plant.. how much power does it deliver, and how large of a solar farm would be needed to switch that power over to solar.. " definitely need to figure out a widely deployable energy storage method for solar energy -- like using existing dam's to pump water back up into the reservoir type thing.
There is almost no major city in the continental US where you can't find open land and spaces ~30 miles away from the city center.
Transmission distance matters when you are talking about sending power 1000s miles from the generation location. For that, you want something like HVDC. However, for anything else, HVAC is good enough.
Not just pasturage, but other wasteful and dumb land uses. All of California's energy needs and much more could be provided by a PV plant covering Edwards Air Force Base, with ordinary dirt-cheap panels on fixed mountings.
People greatly overestimate the footprint of solar power, and underestimate the footprint of oil and gas. Every oil and gas well in the nation sits on a 1-5 acre pad that has been scraped flat and denuded of all life. The area that has been sacrificed for this purpose in west Texas and Wyoming absolutely dwarfs the area that we would need to replace that production with PV.
If Germany switched all the land that is currently used for "energy crops" to PV, it could cover a large fraction of its primary power demand. I assume it's similar in other countries.
Wind is even a bit more space efficient in Germany. Land use is really not a problem for renewables.
I find the issue of land use for renewables (especially wind) to be similar as land use for rail and highways. Technically they don't use up a lot of land, but when it is time to actually build there tend to be a lot of problems finding land that people are willing to sell. Either because of noise, or because current utilization of that land would be hindered in some way.
Eminent domain is a common tool to solve this, and it is also used for mining. It is however not very popular.
"Covered in"? No. Corn, and also wheat, yield less in partial shade.
But most crops do not, and benefit both from reduced heat stress and reduced water loss. Livestock, likewise, benefit from shelter, and the grass grows not less, same reasons.
When you have all of cultivated land available to site solar in, you can choose places to put it where it is most beneficial.
Farm and pasture are not the only places that benefit from shade. Reservoirs and canals lose huge amounts of water to evaporation, and need constantly to fight biofouling.
Corn and wheat would be a non-starter since you’d partially/entirely lose the scale of mechanically planting/tassle/harvesting.
Maybe a specialized tractor could be built to go around the panels but really you’d want to grow laborious crops that are mostly hand-planted/harvested anyway.
I don't see what this would have to be the case. You could install the solar panels elevated with support structures wide enough for the harvesters to pass between. That being said, like others have mentioned these crops in particular do like more sun so other crops are likely more suitable. A setup like this (https://s4.reutersmedia.net/resources/r/?m=02&d=20211004&t=2...) would be useful for many types of crops.
In a wheat field, you would put the panels in vertical fencerows running north-south, as far apart as the junk you pull behind a tractor. You are not harvesting a very high percentage of insolation, but it doesn't matter because there is plenty of collection area in total. Wheat fields are very big.
On wheat you may not want to collect too much of the light anyway, because yield might suffer.
Corn is a little harder because it grows so tall. You would need high fencerows, or give up collecting much when the crop gets high.
One merit of these systems is that they produce revenue in fallow years and year-round, while the crops only produce revenue in a spike once a year.
There might be some studies on corn available, although it's not explicitly mentioned in the article. From the article:
Researchers are experimenting with which plants do best under solar panels and even trying to grow tomatoes and potatoes between rows at existing utility-scale farms, Macknick says.
You can't always grow corn on fields not covered by solar panels as well. Just because they stop one thing, they don't stop everything. You can graze sheep and poultry, you can transport water, people, vehicles, you can park your car, or build a building.
the sight and sound impact of a wind turbine is real though newer models are a lot quieter. if i lived out in the country where it was quiet i'd be against someone putting them up super close as well.
just calling everyone a "NIMBY" is not a valid response to criticism of externalities.
On shore wind has the lowest LCOE (even excluding subsidies) of any utility scale type of energy; significantly lower than coal, and a bit lower than solar or nat gas.
This has been true since about 2015 (if you include pollution externalities) but solar is on track to move ahead about now. The more important thing is that both are below fossil fuel alternatives, and can complement each other.
The exact blend depends on the location of course, but any sensible grid will likely include both of them (and mixes of distributed solar, onshore, offshore wind). Generally solar and wind should be about 80% of the generation mix, and the precise balance (after including the cost difference over the next few decades) globally leans towards solar being the dominant of the two in most plans and predictions.
edit: this has now made me wonder if anyone calculates the LCOE of 'optimal' solar/wind mix for the region.
Mixes are great. I think people are underestimating the ability of batteries, though. With the new 30% ITC in batteries (and rapidly declining costs), expect to see a lot of new utility-scale batteries over the coming years. We could see 100% of the generation come from solar if we have reliable battery storage; in many areas the bottleneck on getting solar installed is cannibalization risk and interconnection times (i.e. transmission lines / transformer access), not economics. Batteries are what get us from 20% generation (during peak daylight hours) to 95-100%.
Anecdotally, having lived in areas where wind farms were repeatedly proposed and then rapidly shot down by neighbors, the NIMBYism was never about science, much less methodology. The kinds of people living in places where you'd want to build wind farms (rural ag land, mainly) tend to be pretty traditional, conservative, anti-government, independent, and basically it's-my-land-dammit types. You can show up with presentations and videos and visualizations and simulations and offer free power and cash incentives and all that, but it usually boils down to "No, because I don't like it, and I don't like you, and I don't trust people like you". It doesn't matter how technically sound a project is if it still seems like "here's another bunch of suits trying to sell us something that only benefits the city dwellers we hate 500 miles away, while telling us they know our land better than we do."
Their values and systems of belief/reality-building and trust networks are totally different. Successfully negotiating that doesn't mean "my numbers are more correct" but understanding the different subcultures, what's important to them, and being able to respectfully and empathetically communicate according to their needs, not yours.
Oh, don't get me wrong, I'm under no delusions that you can convince these people.
My primary reason for sharing it was to avoid other (reasonable) people from walking away with some false belief that there might be something to the noise issue. There isn't anything to it.
I'm not trying to convince this person. However, there might be others who don't have the time to do the research. This comment is for them.
If they are so un problematic why not fill for example central park with them? And then parks in other cities. The ground under can be still used for recreation, when there isn't risk of falling ice. Seems like small trade-off for any ecoconsious person.
There are some sensible regulations wrt placing wind turbines. For example you don't want the blades' shade to hit homes for more than a couple of minutes and you want sufficient distance to buildings so that the blades can fall off without hitting any. These regulations however are not strong enough for NIMBYs who don't want to even see any turbines.
Where in the world do you see that problem? Doesn't match anything I've encountered about the topic, and I have family members deeply involved in the planning and permission process for such things.
People generally like making money with their land, and especially for wind it often doesn't impact the economics of current land use very much. (And even solar isn't necessarily exclusive)
The comparison with rail and highways also isn't very good since for those there are much stricter constraints to cover a useful and practical route in its entirety.
Ironically the Sierra Club is one of those organizations behind NIMBY type objections to solar and wind production. They are an outdoorsman club, not an environmental club. Their objective is maximizing the amount of untouched wilderness available, and that means not being able to see wind turbines from mountaintops.
The average farm in the US is around 2 square kilometers. let say a railway road is about 10 meter across, and let say it goes through those 2 square kilometers. How much of that land is taken up by the railroad? 0.5%, leaving the farmer 99.5% to use for everything else. Railroad isn't generally that wide and thus don't use up a lot of land.
The biggest problem in those situation isn't that the actually land that get used, it is how the farmer get impacted by the rail road being there. If they got a lot of money for those 0.5% with no negative effect then naturally people would have no objection to sell that for huge profits.
I can't speak for your family members or the locations where they are involved, but I do know how much politics there is around where I live. There is a lot of resistance to place wind farms on farm fields, and farmers aren't exactly lining up to rent out their land (or at least not for the price people are willing to pay). Ocean farms are often cited as being easier to build because there is less resistance from land owners and local government.
One land location that does seem a bit easier for wind production are forests in mountain areas which is sparsely populated. The draw side is that the consumers isn't generally located there, so you get the situation where the best and easiest locations to install wind is also the worst location to utilize the production.
The land doesn't have to be purchased though, there are plenty of uses which cooperatively use the land. Parking lots, and solar-agriculture. The coop use may even improve the hybrid performance - a little less sun and a little better shade microclimate for humidity can even be a crop yield booster (esp with climate change induced droughts).
Just putting arrays on commercial rooftops is the most cost-effective solution by far. And no you can't really grow crops or much of anything but low grass/weeds under the panels due to 1) the problems (of shading with tall weeds or crops), and 2) the potential for damaging the surprisingly fragile wiring.
(And don't get me started on this, but most arrays are wired stupidly, ignoring what the telegraph and phone guys learned 125 years ago: you want to ground the positive leg, NOT the negative, so you can use cathodic protection via a sacrificial anode to prevent the wires corroding away. You would be shocked how many 10-15 year old arrays I've seen that have something rapidly approaching empty straws of insulation connecting the panels - the breakeven on a solar PV plant is around 20-22 years, so these will never break even!)
In the US, just the switch to EVs will reduce the amount of land used for energy, since ICE engines need ethanol as a lead replacement, which is sourced from corn.
This is just falsehood. Ethanol gas is a pure subsidy program. It serves no utility other than ensuring fuel quality corn gets grown.
Edit: They don't add it to the fuel because they want to. They do it because they are mandated to. Anti-knock properties are just a tiny silver lining that could be obtained through more efficient means were it not for the subsidized ethanol.
> Due to the phasing out of MTBE as a gasoline additive and mainly due to the mandates established in the Energy Policy Act of 2005 and the Energy Independence and Security Act of 2007, ethanol blends have increased throughout the United States, and by 2009, the ethanol market share in the U.S. gasoline supply reached almost 8% by volume
and
> In the U.S. MTBE has been used in gasoline at low levels since 1979, replacing tetraethyllead (TEL) as an antiknock (octane rating) additive to prevent engine knocking.[15] Oxygenates also help gasoline burn more completely, reducing tailpipe emissions and dilute or displace gasoline components such as aromatics (e.g., benzene). Before the introduction of other oxygenates and octane enhancers, refiners chose MTBE for its blending characteristics and low cost.
It is a farm subsidy program, but it also has an actual use. Oil companies went with lead in the first place, despite being well aware of the dangers, because ethanol is also a competitor to gasoline, being a fuel itself.
Ethanol is probably the best option we have for anti-knock, but corn-based ethanol is worse in pretty much every way compared to other sources of ethanol like switchgrass. So while ethanol itself has a use, corn-based ethanol is pretty much just a farm subsidy at the cost of the environment.
Yes, Archers Daniels Midland collects a monstrous undeserved federal subsidy.
But unleaded gasoline needs something to raise its octane rating. MBTE turned out to be a public health and ecological disaster. What we use now is ethanol. Probably some other alternative would be cheaper and not burn crop acreage, but wasting corn has been good politics: corn farming states have a preponderance of senators.
> unleaded gasoline needs something to raise its octane rating
Probably naive, what does this mean? There are unleaded gases for sale that are ethanol free at some gas stations (typically only the premium / highest octane) which are often preferred for small motors / high end engines. I don't think they mix in lead, is MTBE what is added instead in those cases? I haven't heard of MTBE before.
ETA: I've been able to find a number of sites for WI gas stations saying "we have ethanol free," but none of them mention what is added in its place (if anything).
That's a UK supplier but an answer on Quora suggests 'race' fuels are sold in the US with lead too. Not legal to use on the road though.
> Effective January 1, 1996, leaded gasoline was banned by the Clean Air Act for use in new vehicles other than aircraft, racing cars, farm equipment, and marine engines.
The presence of small amounts of lead in a niche motor fuel product in a country that doesn't have a corn industry to speak of in ethanol subsidy program is irrelevant to the point of dishonest when the subject at hand is US corn subsidies.
The only leaded fuel you can buy in the US is aviation fuel. You can't buy it at a gas station and the only reason it still exists with lead in it is because that is necessary for compliance with government rules that regulate what fuel can be sold for that specific purpose.
You probably replied before I added the bit that suggests in America it's still legal to use leaded fuel in racing cars, marine and farming equipment (as well as aviation, as you mention). I found several posts from people saying that they buy aviation fuel because they don't like ethanol for their lawn equipment, and presumably people informed enough about the issue to intentionally buy leaded avation fuel would know about other options available).
You do get alkylate gasoline, maybe that's what is being sold:
> The availability of alkylate petrol is limited. The actual alkylation process to produce Aspen is a much more advanced and expensive process which only a few refineries in the world can produce. Even if new ways of producing alkylate petrol is developed, regular petrol will still be the dominant type of motor fuel in the world.
I found this website, that lists places that sell ethanol free gas, and the number of them that appear to be Marinas, combined with the bit above about lead being used for marine purpsose makes me think they're just using lead.
>You probably replied before I added the bit that suggests in America it's still legal to use unleaded fuel in racing cars, marine and farming equipment (as well as aviation, as you mention).
Somebody call Congress! Think of the children!
Pretty much nobody does this because on the high end race fuels as well as various alcohol fuels are more available and better supported by industry and on the low end ethanol free premium is substantially cheaper. If lots of people did it it wouldn't still be legal. Dumping 100LL into your boat or race car just isn't a good value way to solve a problem anyone has.
> I found several posts from people saying that they buy aviation fuel because they don't like ethanol for their lawn equipment, and presumably people informed enough about the issue to intentionally buy leaded avation fuel would know about other options available).
I hope I'm not the only one appreciating the schadenfreude here. It reminds me of when people unscrew the spout from their crappy compliant cans. Regardless, the overwhelming majority of these people just drag their butt to whatever local station has ethanol free premium rather than go to the airport because it's a faster/easier/cheaper way of accomplishing the same goal.
The current status quo is stupid but the rules are written by a bunch of jerks who either a) DGAF about what happens beyond the next election cycle or b) DGAF so long as they're not responsible and can collect their pension so it's no surprise that the things people do to compensate are non-optimal.
Replying to myself, looks like you can either live with lower octane ratings (like 87 which might work for some boats, when some modern cars want 95), or add more benzene, toluene, ethyl-benzene and xylene instead of ethanol, but it's more expensive. Apparently some of the ethanol free options like Rec90, are specifically marketed as Recreational, i.e. not for automobiles, as no real study has been done on their use for that purpose.
It's funny you linked to buyrealgas - I had been trying to avoid them since they seem a bit.. radically anti-ethanol ("first of all, we're literally burning our food!"). Anyway... never heard of using av gas in a lawn mower, that sounds crazy to me. Maybe I'm just hugely naive on small motor mechanics, but the difference between standard, 10% eth 87 and premium eth free 91 seems to be about 0, performance wise, and if you end up cleaning the engine once every year or two anyway... idk. I think I mentioned above, but my frame of reference is Wisconsin. Outside of Milwaukee/Waukesha county, most gas stations sell eth free premium, and many people here actually do make the trip to get it.
The problem with ethanol in power equipment is that it tends to dissolve rubber seals/tubes. For some reason small engine manufacturers were extremely slow to switch to ethanol safe rubber and as a result one of the most common failure modes is for the carburetor jets to clog up with nasty semi-dissolved rubber. It's also just the case that people keep their old 80s and 90s lawn mowers running because they only put a couple dozen hours of runtime on the things each year so they don't tend to die except when the ethanol wrecks the fuel system.
An additional issue for low use stuff is ethanol is hydroscopic and many of the other compounds are volatile. Even in a steel tank most modern fuel turns into pink slime after some months.
Large tanks are generally okay, but if you try to start a small carbouretted engine after 6mo and haven't drained the tank you'll need to clean the jets and replace the spark plug.
You don't necessarily need to add anything depending on the engine being used. from my limited understanding most small, carbureted engines do perfectly fine on gasoline without an anti-knock additive. more intelligent engines will usually retard timing with low octane fuel so that the engine doesn't knock but you will lose power.
"corn farming states have a preponderance of senators"
And the first primary or caucus state of the election season is Iowa. The state produces the most corn in the Union and by far the most corn per capita. Large corn subsidies will likely continue until this fact changes.
Well, they have 2 senators like all the other states... perhaps though that's suggesting that they're sparsely populated so their senators seem out of proportion to the small number of voters they represent (compared to their Representatives, who are few compared to populous states like CA, NY, TX, GA etc.) The Iowa caucus system certainly is an attention-grab, but I don't think it's single-handedly responsible for the whole system of ag subsidies (which presumably has also been championed by other farm states like NE and KS).
> Thanks to federal protection of the domestic sugar industry, ethanol subsidies, subsidized grain exports, and various other programs, ADM has cost the American economy billions of dollars since 1980 and has indirectly cost Americans tens of billions of dollars in higher prices and higher taxes over that same period.
> At least 43 percent of ADM’s annual profits are from products heavily subsidized or protected by the American government. Moreover, every $1 of profits earned by ADM’s corn sweetener operation costs consumers $10, and every $1 of profits earned by its ethanol operation costs taxpayers $30….
I know how farm subsidies work. Most of it is crop insurance. ADM doesn't get anything to their bottom line when a farmer gets their crops insured at an affordable price.
Completely agree. I think we are seeing two things here:
1. Lobbying groups for fossils and nuclear trying to find disadvantages of renewables. The most bizarre thing I saw a while ago was arguing strongly for nuclear largely based on the fact that it's more space efficient (saying the importance of that outweighs cost), while completely ignoring the fact that nuclear plants require extensive nofly zones (note theybare not really a problem atm either but would affect how much we can build out nuclear).
2. A strong push for making large scale renewable installations. While it is true that large scale solar is more efficient than smaller scale, I think the prime motivation is that it benefits large operators and investors, not individuals or small communities. Hence the lobby efforts.
In reality just putting solar on most existing warehouses and parking lots would already cover a significant proportion of our electricity use. And others pointed out how solar (and wind) can often be used in dual use environments benifiting both.
Lobbyists in California have made multiple attempts to destroy solar, including existing residential installations. They failed their first attempt last year and are pushing again this year [1]. The proposal is a tax that is so high that solar panels will lose you money.
I do think that space efficiency and good availability for nuclear are a reasonable argument for that technology. That doesn't mean we also shouldn't be putting solar onto every flat surface in the country, homes, businesses, parking lots, etc.
Each nuke plant in the US uses up a whole square mile. Worse though, is that it costs overwhelmingly more to build than the solar generating capacity that would displace it. Furthermore, you burn enough coal in the time it takes to build it as would pay for another matching solar farm.
Renewables aren’t cost constrained, they’re constrained by the rate at which we can buy and install the panels, turbines, storage, etc. We literally can’t build renewables fast enough, so not only can we build nuclear alongside renewables, but it’s the fastest way to reduce our emissions while also securing our energy supply and diversifying our energy portfolio. It’s not renewables versus nuclear, it’s renewables and nuclear.
It's not like nuclear plants are getting built in a fortnight either. In fact the ridiculous lead time on getting a nuclear plant generating electricity is one of the biggest problems with pitching them as a solution to climate change. We have already dithered far too long on this, we can't wait 20 years to reduce our carbon output, solutions need to be built in the next 5 years or less.
Please re-read my above comment--I'm very specifically and explicitly not proposing forestalling renewables for 20 years while we build nuclear plants! I'm proposing we continue building out renewables at full tilt while we also build nuclear plants at full tilt.
If a $250 million subsidy gets you 2GW of solar/wind backed by pumped storage in 5 years and 1 GW of nuclear power in 20 years it doesnt really make much sense to split a $500 million pot of subsidy money 50/50 between the two.
We would get more GW for the buck by using subsidies to really accelerate the expansion of green power generation that is already cost effective without subsidies (solar/wind/pumped storage) rather than throwing money at a form of power generation that wouldnt even exist without subsidies.
If the subsidies were distributed on the basis of stability, GW output and availability then that would be efficient, effective and fair but that would kill off the nuclear industry entirely.
Right, but you’re assuming that solar and wind are capital constrained, and I asserted above (twice now) that they aren’t (that spending more money on solar and wind isn’t going to get more solar and wind deployed because we’re already building it out as fast as we can).
At any given time you have a rate of capital expenditure you are willing to devote to the crisis. Some fraction of this maxes out production capacity of wind and solar energy equipment. The rest is spent on something else. It can be dumped on building individual nukes, or invested to expand wind, solar, storage, and fuel synthesis equipment production.
Only one of those choices feeds an exponentially increasing capacity to respond to the crisis.
Except that's not the net effect. When you spend $20 billion on a nuclear plant it becomes a lot harder to also spend $5 billion on the same net capacity of solar.
There are plenty of much lower hanging fruit available than a nuclear plant. Insulation, residential thermal batteries, trains, cycleways, green hydrogen infrastructure, solar water heating, CAES projects, variable load upgrades to aluminium smelters, etc. etc.
I'm all for increasing public spend on green energy, but until there's enough money for the cost efficient things, then nuclear is just helping the fossil fuel industry
I repeat: solar and wind aren’t capital constrained. We’re already installing solar and wind as fast as we can, so spending an extra $5B isn’t going to get you any more solar or wind, so we should spend the extra money on other clean energy sources.
You could build production capacity and the panel for less than the price of nuclear and in less time. We're not constrained to only silicon or cadmium panels either, there are more expensive or less efficient (but still vastly cheaper than nuclear) chemistries that are made from abundant materials.
Or just do any of the other things on the list I mentioned. Getting 400 commuters out of cars and into a train is an instant 4MW saving.
That's at the same time true and misleading. Land usage for energy crops will vary year on year (natural crop rotation). On top of that, only some crops are really disturbing people living close by (e.g. rapeseed stinks when wet). Large-scale PV installations really look and feel bad when you live or walk right next to them. Wherea a field of wheat, corn, or rapeseed somewhat feels natural and even has its beauty, solar panels just look ugly up close.
So the question is: Will you find enough locations that don't annoy the locals and once you found them will your project survive the inevitable intrigues amongst land owners over who gets to rent out their land for the lucrative PV installations?
Even though it's more expensive, I think that using rooftops and other already occupied spaces first is a more sensible route.
Drove by a 108 megawatt, 765 acre installation last week (looked it up later). It really didn’t look much different than the surrounding farm land. In fact you could see further than you could with corn crops. The panels didn’t come all the way to the roadside and rows were perpendicular to the road, so you could see straight through.
If solar panels were more efficient and mass produced in the 1990s, I have to imagine solar farms would have replaced most tobacco farms after the buyouts.
The thing that would bother me about crops nearby would be if they ever sprayed something not-so-great-to-breathe on them (which, they generally do). Solar farms seem like perfect neighbors, by comparison. I really don’t get the whole “solar panels are ugly” thing, it feels almost like concern trolling, trying to muddy the waters.
Though maybe I’m biased by my feeling that solar panels are damn-near magic - you leave them outside, basically neglect them, and power just comes spilling out of them.
I think it's, quite literally, a question of the point of view. I know about installations that were (during planning) allowed to be 4m tall. If that happens right next to your home or any other place you visit frequently, I, and many others, find it extremely ugly. If there's a distance, say 100m, it's not half as bad. If the installation doesn't even block the view (e.g., because of elevation), I don't care at all. But given the plans I have seen, I prefer a couple of wind energy plants about 1000m away.
Solar panels are only like 3-4" above the roof on residential installs. Any extra view blocked that wasn't already blocked by the house is trivial. In fact solar panels are usually not installed all the way to the top of the roofline so there is no change in visibility at all.
Farmers often already need tall tree barriers for wind erosion control. Other farmers may usually without restriction cultivate a tall view-blocking forest on their land.
So let them cultivate a perimeter of just enough forest to hide the panels if it really is a real issue and not a product of NIMBY OCPD.
If you ignore them, then you never know when they stop working. Really. The fact that they look the same working or not is one of the problems with them, and why you really do need monitoring and someone to pay attention to the monitoring at least every few days.
I spent six years in the utility-scale solar PV industry. You would be shocked to learn how many of the panels are not working in any given array. I've seen everything from almost 10% of the strings not even being connected to the inverters in a utility scale array, to a shocking number of rooftop arrays that were producing nothing. In my entire experience with the company and all its customers, we never encountered a single utility-scale array that was fully working when we arrived on site to add our monitoring or optimization systems, and many of those were brand new!
In one case of a sizable array on the roof of a Texas energy provider here in Austin, we discovered the inverter had died years before we discovered it! (This was field testing of of inverter bus noise effects, and the oscilloscope showed nothing but what the wiring picked up as antennas!) Turns out no one ever looks at the power bills in a power company... :-)
Solar PV actually requires a fair amount of maintenance for both prevention and remediation (cleaning and/or replacing panels, repairing connections/wiring, combiners, inverters, etc.) to ensure they are actually operating, but most owners are happier to cover their ears and eyes and sing, "La, la, la..."
Ha! Thanks for the professional perspective! I guess I should up my monitoring plans from “glance at the SolArk screen every now and then” to maybe something a bit more robust/automatic.
Since plants are only about 2% efficient in turning sunlight to biomatter, you'd need a lot more space if you wanted to store winter reserves in biofuel than if you generated electricity and turned that into hydrogen.
Wait, we are going to replace plants that consume carbon with solar panels that do not consume carbon in order to reduce carbon in the atmosphere and save us from global warming? Why does none of this make sense?
"Energy crops" are burned as fuel. They aspire to be carbon-neutral (and are often still fed a lot of petroleum-based fertilizer), not carbon-negative.
You know all that stored carbon gets released as soon as the plants are burned for power, right? As opposed to PV panels which can replace fossil fuel consumption.
> it could cover a large fraction of its primary power demand
For a certain number of hours in the day, yes. This always strikes me as an odd observation because storage and distribution have always been the more important challenges in our current implementation.
I'd also caution against any form of "monoculture strategy." The lessons from history are pretty clear on this.
I meant averaged over a year. Of course storage and transmission also need to be solved. They have even less problems with land use than generation though, which I why they weren't relevant to the point that I was trying to make.
Real estate near major metropolitan centers is not cheap either. With modern orbital delivery dropping by orders of magnitude, the entire equation changes. Get with the modern agenda!
The advantages of orbital are nearly 20X generation per panel to start with, even before considering support structures (none) and weather-proofing (none). That leaves lots of room in the cost equation.
Real estate already generating revenue that may have solar added without reducing that revenue is not expensive. It has, instead, negative cost.
Solar panels do not need to be "near major metropolitan centers". Modern transmission lines move power efficiently, silently, and reliably.
It would be impressive for your orbital panels to get out 4x as much energy as the light they intercept carries, but getting a patent on your perpetual-motion apparatus might be difficult.
Maybe do some elementary cost analysis. All the numbers are easy to find. Don't forget to figure in conversion loss from electric power on orbit to laser light emitted, losses scattering in the atmosphere, and conversion again from laser light received to electricity on the ground.
You would better loft many-square-km aluminized-mylar mirrors to reflect sunlight to solar farms on the ground. Keeping them pointing the right direction would be tricky.
That's so far a pipe dream, dual-purpose 'negative cost'. Also transmission lines need right-of-way and are not free.
Solar flux outside the atmosphere is 9X sea level. Go ahead, look it up. Then there's the periodic eclipse called 'night' that doubles orbital efficiency again. Look that up too.
Conversion losses of 20% seem normal? Both in orbit and on the ground. Which halves what you collect, well within the budget of 20X reducing it to around 10X.
Solar flux outside the atmosphere is not, in fact, 9x sea level. You can cook the numbers by keeping the orbital panel square on to the sun, while the ground-mounted panel rotates through the day and overnight. But you don't get to count nighttime twice.
Conversion losses of only 20% from electric to laser, and again from laser to electric again, would be miraculous. 20% scattering loss in clear weather would be unsurprising. 90% loss, total, would be admirable, not counting the original 60%+ loss off the top. So, even with 9x, and neglecting huge launch cost you still come out behind.
So about 75% of solar radiation reaches the ground. In the continental US, factoring in angle of the sun, average weather, night that comes to about 4-5KWh per day
In orbit you would have just 1.37KW X 24 hours (no weather, angle issues) which comes to about 33KWh per day. So that's 8-9X the collected energy per square meter in orbit vs ground level.
So many things. The massive clear area around your receiver. Scattering induced by weather means you still don't have 100% capacity factor. With only radiative cooling available, cooling will take up as much space as the panels and make everything heavier. The atmosphere doesn't absorb light uniformly. Maintenance. You're comparing fixed panels at mid latitudes to rotating panels. Launch costs are still 10x the cost of a panel. UV and ionizing radiation will destroy your panels sooner. And a space borne panel will probably never reach net energy payback even before you add your laser boondoggle.
> Multiple Gigawatt. Still orders of magnitude better than solar; still less land area.
Land area is an absolute non issue for solar. With the exception of somewhere like luxembourg, just the roofs of the residential areas of a country have enough area to provide the total primary energy consumption. The singular and overriding factor is cost and cost of storing or moving the energy. Which brings me to
> The land-based panels are 42lbs for 450W. The space-based ones are 6W per gram. Lots of room in the equation for cooling.
You're not going to get nameplate capacity, and the weight is in the superstructure, cooling system, power delivery, and your 100s of metres aperture laser or maser. The actual panel for a terrestrial caravan system I installed recently weighed no more than the panels listed here https://www.spectrolab.com/DataSheets/Panel/panels.pdf (although it was bigger).
So you're proposing spending 10x as much on panels, another 10x as much on cooling, spending as much again on a transmitter, then as much again on a receiver. All to burn tens of kg of methane per watt in order to get the thing into a stationary orbit. Then you have a gigawatt death beam fucking up the atmosphere and making a square kilometer or so uninhabitable.
> Like the hot air about 9X being so far from the truth
Comparing like for like, you have about 1.3kW in space vs 1kW on the ground, and a tracking setup can get 6kWh/day out of a 1kW panel at low to moderate latitudes (where well over half of the world's population lives). This is a factor of 5 to 6 better, although your space based panel is vastly more expensive and a tracking system is pointless because cost is the limit, not area.
This is the most efficient high power long range wireless transmission system I can see mentioned: https://ietresearch.onlinelibrary.wiley.com/doi/full/10.1049... which brings the ratio to around 3-4. Except you also have to deal with losses due to clouds and dust so 2-3 is more likely.
At that point just build a nuclear plant. They're awful but they're better than this plan by every metric. Or do the sensible sane thing and build 100x the terrestrial solar for the same price (or 10x as much and enough storage) and save the space arrays for stuff in space -- once you're lifting megatons it makes far more sense to refine metals from asteroids and just leave 99% of them up there.
Or as I said, just burn the rocket fuel in a gas turbine. You'll get more energy out of it than you would from this utterly ridiculous machine in its lifetime.
If area was a constraint important enough to make space based solar viable we'd see water cooled triple junction cells as well as tracking on any utility scale installations near the equator (as this would reduce area by 2/3rds). We don't so it can be safely dismissed as more solar frickin roadways.
The nice thing about solar is that it doesn't have to monopolize the land. If you want to convert a suburban parking lot to a solar farm you don't have to evict the cars, you just have to install them high enough that the cars can park underneath.
Orbital power is a total nonstarter if we aren't building the panels in orbit. Launch costs will absolutely destroy any ROI, even before you get into the transmission losses beaming the power back to Earth. SpaceX has completely revolutionized the launch industry, getting costs down to around $1200/lb. A typical solar panel weighs about 40lbs, but aren't optimized for weight. Assuming you can reduce this to 20lbs per panel that's still $24,000 per panel not counting transmission equipment and the like. The panel itself costs maybe $2000 for a very high efficiency model. The launch costs dwarf the panel costs, even when accounting for the lack of weather in space. It just doesn't make sense, especially when you start adding in all of the additional costs like building the satellites, the ground stations, transmission losses, fuel to keep the orbits from decaying, the fact that you won't be able to send these to Geo Orbit without incurring crippling transmission losses, so you'll need a lot of ground stations, etc...
Compared to all of that, the problem of finding parking lots in the suburbs seems absolutely trivial.
Orbital solar is an incredibly stupid idea that just will not die. Even Elon Musk has been quite open about it being one of the stupidest ideas ever. You only get about 3-4x (NOT 9x) of the power you'd get on earth in orbit, and putting things up there will always be expensive, even if it's finally coming down from NASA et al's comically high prices.
No matter what kinds of launch cost improvements you predict (including, of course, Starship-likes), it will always be orders of magnitude cheaper to just build an array here on earth that is 3-4x larger than to lob anything into orbit.
The Microwave/Laser power transmission schemes of orbital solar are also a huge problem, and in all likelihood would never make it through any kind of environmental impact study, much less an engineering effectiveness/reliability review. (Not to mention that, like the famous laser drive in Larry Niven's Man-Kzin wars, any laser/maser/microwave array that large is inherently a formidable weapon of mass destruction, with no modification other than repointing it....)
Except all that has changed. The multiplier is real; ground-based doesn't scale well; environmental problems with microwaves are chicken feed compared to large-scale sterilization of ecosystems by huge solar farms.
Technology moves on, but old wet-blanket excuses live forever.
The article is very light on the technology. (Quad Junction) GaAs cells have been produced with >40% conversion efficiency. That's more than three times the efficiency of Si or anything else in common use. The GaAs cells have thus far only been used for space-based applications. Somebody should be working on getting production costs down and deploying these things terrestrially.
40% is not, in fact, 3x, or even 2x, current best efficiency of Si or CdTe panels.
And, the important efficiency measure is W/$, where GaAs trails well back. Perovskites may exceed 40% conversion efficiency, and also have good prospects to offer much better W/$. Their endurance has grown encouragingly quickly.
If we are talking about solar installations on land, rather than in the built environment, the W/$ also needs to factor in the cost of the land itself, which is at a premium in many places including across Europe. On that basis there is scope for an increased efficiency to lower the cost delta.
If you looked at the first link I cited, they claim 47% efficiency is possible. That is more than 3x the efficiency of many Si panels on the market today. Unlike perovskites, which to date have only achieved ~25% efficiency, GaAs cells have been produced with efficiencies approaching 70% (under laser illumination). https://www.ise.fraunhofer.de/en/press-media/press-releases/...
W/$ goes down with manufacturing efficiency. Nobody has done large scale manufacturing of multi-junction GaAs cells.
If you looked at the first link I cited, they claim 47% efficiency is possible. That is more than 3x the efficiency of many Si panels on the market today.
Top-end GaAs technology wouldn't compete with bottom-end silicon technology (the below-16% panels that you mention). It would compete with top-end silicon technology, which is already commercially available at module efficiencies above 22%:
GaAs cells reported to operate above this limit are part of multi-junction cells and/or incorporate optical concentration systems to focus sunlight to higher intensities. The experimental record-holder of 47.1% uses a multi-junction cell plus optical concentration. Optical concentration only works with direct normal illumination; light that is scattered through haze or clouds can't be focused, so optical concentration systems are a good match only for sunny areas that have clear skies year-round.
That said, the National Renewable Energy Laboratory is researching ways to make GaAs cells at lower cost:
At low enough cost, GaAs modules could compete directly with premium silicon solar modules. They could conceivably be lighter as well as more efficient than silicon, since thinner layers of GaAs are needed than silicon layers, which in turn reduces the required module rigidity, thickness, and weight.
The fine article was about the efficiency of cells vs. their geometric footprint. If the cost of the footprint is considered, smaller GaAs cells might be more economical than the larger (but cheaper) Si cells. Also, conentrators might be nothing more than a few mirrored/angled surfaces at the edge of the cell, which would increase cell illumination independent of cloud cover. It's not rocket science.
Yes, but is anyone seriously considering multi junction panels for stationary applications? When there is an abundance of free rooftops and parking lots and plenty of low quality rural land for under 20 cents per square metre it doesn't seem to make a lot of sense to pay over double for less than double efficiency.
For the case of perovskite cells, adding layers does not seem to multiply the production cost.
Certain uses place a premium on areal efficiency, notably aerospace.
But anybody who has maxed out their own collection area, whether a roof or reservoir, can get more revenue from using better cells. And, the more of that that is done, the faster their price falls. We may reasonably expect the price of multilayer perovskites to drop below cost of silicon panels. Sooner is better, which is driven by maxed-out demand.
Parking Lot solar makes a huge amount of sense. Not only does it create power, but it creates shade for the parked vehicles and cuts down on the amount of heat absorbing blacktop visible to the sun. The suburbs are absolutely covered in parking lots that could be converted. Nobody is going to complain that the solar array is despoiling the aesthetics of the suburban parking lot either.
Really the only downside is that people will crash their cars into the support structures. It is inevitable, and needs to be accounted for in the design.
I am not saying this to be pedantic, but people will 100% complain about solar arrays in parking lots. Green energy is a politicized and having solar parking lots will be used as a political talking point. It already happens with electric cars, wind farms, and much more.
Well yes, there are always cranks to complain about everything. But as long as they are just the usual cranks it's not really a problem, especially if you can make them look foolish in front of the planning committee by showing a "before" picture of the hideous parking lot.
I wonder if it would be a possibility to relay electricity across the US with large battery stations from big solar farms, or if the loss in transit + the expense of the batteries would make something like that intractable.
So Cal has Sunrise Power Link which is high voltage transmission lines specifically designed to bring in power from the solar and wind farms in the desert. The proliferation of solar farms in the desert is a clear indicator of how that has gone.
Growing up in San Diego I hilariously remember environmentalists protesting the Sunrise Power Link. The reason given by my high school classmates who were involved in the protesting was that it threatened some desert tortoise's habitat or something like that. There were also some NIMBY types protesting the transmission lines.
From the gas and oil companies' perspective, with enemies like these, who needs friends?
I've been wondering lately if it wouldn't make sense for power companies to offer a battery incentive program to homeowners. They'll cover 1/2 the cost of a battery but mandate that the system be set to draw from the grid when production is high (middle of the day mostly) and be used to power the home in the evening when demand is high but production is tailing off.
Some companies do Time of Use contracts which do this to a degree, but flat incentives (cut a one time check to the homeowner) seem much less complicated. The grid gets smoothing and the homeowner gets to keep the lights on when the power goes out and doesn't have to spend nearly as much on the install. The power company doesn't have to manage a big bank of batteries somewhere and saves on distribution costs. Plus the homeowners technically own the systems so when something goes wrong the power company doesn't have to roll a truck to fix it.
The only real problem with this scheme is that the battery market is already squeezed with so many companies jumping into the electric vehicle business and production lagging behind demand. However, this is likely to be a short term problem, so hopefully in the next couple of years something like this will be practical.
True, but there are numerous other costs with doing industrial scale storage. You need to buy the land. Need to design and build the facility and interconnects. Need to do the permitting, environmental review, and other paperwork. Need to do the maintenance and deal with security. Building a facility like this usually involves buying all of the batteries at once, which is difficult in a supply constrained market like we are in now.
A sharing program foists most of this complication off on homeowners.
Your comment shows you really don't know much about solar PV. Deserts are horrible for solar, for two major, and a bunch of minor reasons:
1) Heat kills PV efficiency, since, to a first order approximation, current is proportional to irradiance (deserts good), but voltage is inversely proportional to temperature (so deserts very bad). You make way more power on a clear winter day in Colorado (assuming no snow on the panels!) than you do on an Arizona summer day. If you don't like this, take it up with God, since it's just the way he built the universe and the quantum physics of semiconductor junctions.
2) Dust (and/or salt, if you're anywhere near the ocean) is a huge enemy of solar power production (so deserts bad, again). Dust or salt spray can easily cost you nearly half of your power output. PV panels are scarily susceptible to even small shading from leaves or even bird crap on them. I can throw a business card on most panels and take out 1/3 to 2/3 of that panel's output. If wired in a string, as is typical for utility scale PV, the loss of that single can take out the power production of that entire string (typically 12-22 panels worth), since it can no longer reach the inverter bus voltage set by the unimpaired strings.
Oh, and cleaning panels is really expensive - it was $0.50/panel a decade ago when I was collecting the largest database of DC solar panel data in the world - I don't imagine it's gotten any cheaper... (One of the big selling points of our software was that it could optimize cleaning and maintenance timing and intervals. This can actually make the difference between breaking even on the array cost or not!)
> I can throw a business card on most panels and take out 1/3 to 2/3 of that panel's output. If wired in a string, as is typical for utility scale PV, the loss of that single can take out the power production of that entire string (typically 12-22 panels worth), since it can no longer reach the inverter bus voltage set by the unimpaired strings.
Wait, how does this shit even work at all, then? Are solar farms just perpetually functioning at <50% capacity because everything broken all the time?
This used to be true for cheap panels. Better panels would have bypass diodes for every cell (the 10x10 cm square) and would only loose the output of the affected cell.
You'd like to think there would be some monitoring - on my roof at home, I had something smash one of my 20 panels, right in the middle of the grid (probably a bullet falling after someone shot up in the air, but I like to pretend it was a meteor...) I didn't notice the output was halved for weeks.
i had a hunch this was the case on cleaning, I think around my area Auckland, New Zealand not able to clean it yourself is the difference... does this mean the maintenance company are rent seeking the margin, and if so why aren't panel makers do cleaning as well? or is cleaning such a un-scalable operation that it's best left to lowest bidders?
I just don't see how land use is an issue worth worrying about right now, climate emergency and all. The federal government owns _huge_ swaths of sunny arid desert land in the west. It is largely not suitable for crops, livestock, suburbs, etc. We could install millions of acres worth of current solar tech out there and generate enough power for everyone. The real difficulty lies in the infrastructure it would take to get the power to where people are.
What we should be focusing on is transmission and distribution, those are the really hard problems. We could have all the power we want but if our grids can't handle the rapidly increasing demand it does nothing for us. And as more people go 100% electric for transportation, heating, and cooking the integrity of power distribution becomes even more important because we will have put all our energy eggs in the electricity basket.
The only place land use seems relevant is for smaller scale off-the-grid cases where someone's property is small but they want to generate all their own electricity.
> just don't see how land use is an issue worth worrying about right now
1. In small(ish), densely-populated countries, land is in short supply, regardless of any socio-economic-political considerations.
2. In many countries, land is private, or has been fully "divvied up" in some form or another, despite being only sparsely used. In these countries, reallocating land is a headache - politically, economically and legally.
But I agree that storage, transmission and distribution are important things to focus on. Or rather - the important thing to focus on is to actually deploy lots of solar instead of fossil (which the recent US federal legislation makes even harder than before).
Because the technology is in good enough shape already to partially replace fossil-fuel-based production - at least in day-time. Some might even claim that it can replace fossil-fuel-based energy production in daytime entirely, and with existing storage tech, perhaps even mostly-replace it in night-time. But the first claim is sufficient and AFAICT pretty much in consensus.
> What do you think, expect or hope this will accomplish?
Significant reduction in greenhouse gas emissions by burning less coal and natural gas.
Secondary potential goals:
* A motivation to switch to synthesized car fuel / fuel cells / electric.
* Improvement in air quality around where coal-fired plants operate now.
OK, that isn't a bad perspective to have. Most people are not aware of the realities (vs. the fantasy) of solar and go straight for variants of "save the planet", which is absolute nonsense.
Having and living with solar is very different from what people imagine solar to be. Here's a simple example from my 13 kW array:
What are those massive dips sometimes causing a reduction of output of more than 50%? Clouds. Simple as that. This is what a "normal" clear-sky day looks like:
Output like that is frequent but not the norm. Clear sunny days in Southern California. If you live somewhere with more weather than we have here, it will be more like the first example.
The consequences of weather are severe. Here's a look at January of this year:
This is to say at least two things about the reality, vs. the fantasy, of solar:
First, the technology isn't reliable. Not inherently, of course, the power output reliability is a function of weather. And we can't control that. I can't think of a single place on earth where there aren't any clouds, rain, fog, storms, dust, etc. Note from the images I provided that my 13 kW array never really peaks out at 13 kW. I think the most I've seen is 11 kW. You would need an absolutely perfect day with perfectly clean panels to, maybe, reach a higher peak for a few seconds.
Also note where the annual production peak is located, May. Most people think solar peaks in the summer. Not so. Panels have a negative temperature dependency. Which means they make less power when they get hot. May, here, happens to be the balance point between incoming light and lower temperatures.
Having built and operated this system for a number of years, here's the biggest problem with solar as I see it (and this isn't something trivial):
A solar system built to deliver steady-state power 24/7 must be about
10 times the size of the required steady-state output.
In other words, if you want a solar power plant that can deliver 1 MW (Mega Watt) 24/7, you have to install about 10 MW of solar panels and a massive storage system.
I've done the math on this multiple times, it's undeniable. Some of it is very simple and some of it requires basic high-school calculus. Here's a couple of examples:
The area under the roughly parabolic shape of normal (ideal day) production is 2/3 of that of the rectangle that would represent steady-state power at the peak level for those 12 hours. In other words, you start to produce at, say, 10 kW at 8 AM and stay at that level until 8 PM.
That simple reality means that, in order to produce the same energy of a steady 12 kW power source you need to multiply your system size by 1.5. In other words, if you need 10 kW x 12 hours of energy, you need to build a 15 kW system.
The next easy to understand reality is that you need to double that system (at a minimum) in order to have that much energy available at night. Now we go from a 10 kW system to a 30 kW system plus the corresponding amount of storage.
Another easy one is inverter (and related components) average efficiency. I'll place that at 90%. That means you lose 10% just to make power you can use. It also means that we now need to add solar panels in order to achieve the required output. That...
> The real difficulty lies in the infrastructure it would take to get the power to where people are.
I live in Oregon and slightly over 1/2 of the state is federal or state owned land which cannot be purchased. Even out in the middle of nowhere, there are still massive transmission lines carrying electricity from one part of the state to another through these areas. This is often in fairly mountainous terrain and dense forests. I'm often in awe at how much work they have to go through to keep the area immediately around these lines clear of trees and vegetation. I explore forest roads quite a bit. This is just to point out that we've been doing that type of thing for a long time and I don't think transmission itself is tremendously difficult. We just lack the will.
If anything, the fact that its federal land probably makes it more feasible to run those sorts of clear-cut transmission lines through areas. You don't need to establish easements or eminent domain private property to build such things.
There are some challenges with transmission, but I think the bigger ones isn't necessarily building the infrastructure -- it's making the transmission lines themselves more efficient and reducing losses. We can't build all our solar in the southwest of the US and then distribute that all over the country; Our current transmission technology would produce too much loss over such distances.
Curiosity question for the large scale pros. How is rainwater runoff handled in these large solar farms? Trenches and drains to retention ponds? Or do they somehow try and redirect the water under the panels to utilize the surface area under them?
Impacts to watersheds are the biggest environmental issues of any small or large scale building projects in my neck of the woods. I’m only allowed 12 percent of my land for impervious surfaces.
The panels are only a few m apart. The only difference between that and a fallow field is going to be slightly lower evaporation, and maybe a hair more erosion until grass establishes itself
Found motivation to look it up. This document suggests leaving enough space between the rows to accomodate the runoff.
"EMLR allows solar panels associated with ground-mounted solar farms to be considered
pervious if they are configured in accordance with the recommendations in this chapter.
These recommendations promote sheet flow of stormwater from the panels and natural
infiltration of stormwater into the ground beneath the panels."
...
"In general, the minimum disconnection length between two rows of solar panels is equal to the
width of each row, as shown in Figure 1. However, some panel layouts include horizontal gaps
between individual modules that allow stormwater to drip off the panels at intervals much
smaller than the width of each row. In these instances, the solar farm can be designed with a
smaller disconnection length, provided that they will not cause concentration of stormwater
runoff."
Consider tokyo as an example of a space where area is at an absolute premium. There are around 7000 people per km^2
Shrink it down to a single block. Tokyo's blocks are a little smaller, but a common size is 100x200m for ease. At 0.7kWh/day/m^2 there are 14,000kWh/day available in this area shared between 140 people. This is about 100kWh/day each.
This isn't quite enough to be as absurdly wasteful as someone from Australia or the US, but it covers the total per capita energy consumption of people living pretty much anywhere else.
Note that this is just the net solar electricity available in a high density metropolis as an input vs all energy (including thermal) used everywhere.
As soon as you add in medium density towns or industrial areas there is an abundance of space for panels so long as we stop being exponentially more wasteful with the available energy.
Anyone bringing it up is a fossil fuel or nuclear shill.
230 comments
[ 3.4 ms ] story [ 261 ms ] threadIn the meantime, they are quite a lot cheaper to make, so in many uses it would not matter so much if they did fail faster. In some uses, like aerospace, their lighter weight and better areal efficiency are essential, and forgive a lot.
Hard disagree on that, their current longevity is comparably tiny so you'll have lots of overhead in installation costs. Not to mention the amounts of toxic lead trash you'll need to pay to dispose of, the thing is basically poison after all.
Makes far more sense to invest in multilayer tech even if it costs more since it'll last longer by an order of magnitude and use far less area to function which is a big benefit for vehicles too.
The thin films amount to very little mass, and in any case may be incinerated and the ash used as feedstock.
Longevity is already up to years. In many uses that is plenty, especially when you can just roll it out, instead of needing to bolt it up.
Well that's news to me, I thought that was part of the core functionality.
is an overview,
seems like for places where you could use silicon, but are limited by space and need high output then thy hybrids from Oxford PV seems ready, but I'd guess that's going to be a tiny share compared with people who just want it cheap and at scale.
https://www.oxfordpv.com/news/towards-better-understanding-l...
But hopefully that is enough for it to get proved out and scaled up.
Recall seeing a video of their factory printing solar cells.
Looked great but nothing on their site suggests they have a product unless anyone knows different?
They are listed on Warsaw stock exchange (and having a miserable time of it as the price would suggest).
But in reality, land use has never been a problem for Solar. It's great that lots of people are working on the issue and improving it. Just as lots of people are working on making them cheaper, or more environmentally friendly or easier to finance or a thousand other metrics.
But none of those were ever fundamental problems with the tech. Their own source of data about the 'problem' puts Ground-based PV at about the same land use as Coal.
They also missed out 'floatovoltaics' (PV on water) and building integrated PV as well as solar PV as a paving solution. Probably all of which are likely to be bigger than ground mount PV, given the trend to bifacial panels.
Solar farms are often sited, stupidly, in deserts, not because it is a good idea, but because ignorant investors think it is a good idea.
Perhaps indulge our ignorance about deserts for a moment?
Siting panels on water and on farmland reduces operating temperature. Mounting vertically, in fence-rows, keeps off dust, collects more during morning and afternoon demand peaks, aids convective cooling, and protects crops from harshest afternoon sun.
https://ourworldindata.org/land-use-per-energy-source
I'd assume coal uses much more land in absolute terms, since it's what 50% of global electricity vs 3-5% for solar at the moment.
Better energy density will also help locate solar power closer to where it will be used, like on top of buildings in the city rather than in a large plant out in the middle of nowhere, thus saving on transmission costs.
Finally, IMO photovoltaic pavement is probably going nowhere.
In fact, sharing improves efficiency of the panels, cuts water loss, and often increases yield.
"Often" != "Always". Therefore you also agree that solar still competes for land use with crops.
Furthermore, land that has already been allocated to grid scale solar has already been taken away from possible crop use. Sometimes it's not arable land, but that isn't always the case, therefore solar is still ostensibly taking up land that could be used for crops.
Finally, I even disagree that somebody knew that solar and farming could use the same land. Someone had an idea that maybe they could coexist, then ran an experiment that succeeded. They certainly didn't know the outcome beforehand.
No. It just means that some places are better than others.
Since there is overwhelmingly more crop and pasture land than could ever be needed to satisfy power needs, solar may be placed exactly and only where it does the most good.
It has been known for centuries that most plants benefit from partial shade. It is an exceedingly tiny step of logic to go from "shade" to "shade provided by solar panels". In the past, providing shade just cost money. Now it yields direct revenue, year-round.
Again, "most plants" does not necessarily include "crops", most of which have been selectively bred over millennia while grown under full sun. The step is not from "plants do well under shade" to "plants do well under solar panels", it's to "crops we've never grown in partial shade might actually do better in partial shade too".
When it is an issue there are countless solutions from sharing with livestock (already done in some areas) to providing partial shade for non energy crops like lettuce or capcicum that increase yield to covering parking.
For reference, there are about 2.5 billion parking spaces in the usa which take 20-50m^2 each, very little of which is more than three stories deep. This is room for between 1 and 5 TW of net (ie. averaged over the year including nights) capacity or roughly the USA's entire energy consumption. You could also replace a small fraction (about 5%) of corn used for ethanol (not the total corn) and get a similar result.
> Sheep grazing under solar panels at farms in NSW's Central West have produced better wool and more of it in the four years since the projects began, according to growers.
> Local graziers have labelled the set-up a "complete win-win", with the sheep helping to keep grass and weeds down so as not to obscure the panels.
This is not something that works so well with open cut coal and down wind from city supplying coal burning power stations.
[1] https://www.abc.net.au/news/rural/2022-05-30/solar-farm-graz...
https://thesolarlabs.com/ros/floating-solar-farms/
This is stupid. The article leads with the solution to this non-problem. There is no shortage of pasturage to site solar in. Likewise, of reservoirs and canals. Both places get net benefit from the dual use, even discounting the extra revenue.
I would probably agree if you are referring to USA. But I would be skeptical that the same is true in the UK.
It is true, that the amount of solar needed to power the entire US is about 0.5% of the land.
That doesn't mean there's no benefit in increasing the efficiency of panels and get dual use of the land. It also has the benefit of allowing for solar in more places where it's needed for more decentralized power.
Pretending there is some sort of shortage of land to site solar in is not a valid reason to court efficiency. There are other, legitimate reasons.
> Solar energy is one example where the context and type of material matter a lot. Solar panels made from cadmium use less energy and materials than silicon panels, and therefore use less land per unit. It also matters a lot whether you mount these panels on rooftops or on the ground. Rooftop solar obviously needs much less additional land; we’re just using space that is already occupied, on top of existing buildings. However, they do need some land over their life-cycle because they still require mining of the materials to make them, as well as the energy (mostly electricity) used in refining the silicon. Finally, the density and spacing of the panels also makes a difference.
> Wind is the most obvious electricity source that we should consider differently when it comes to land use. You find it separated from the other sources, at the bottom of the chart.3 There are several reasons for this. First, offshore wind takes up space, but it’s marine, not land area. Second, onshore wind is different from other electricity sources because you can use the land between turbines for other activities, such as farming. This is not the case for a coal, gas or nuclear plant. This means the land use of wind farms is highly variable. I have calculated the land use of 22 of the world’s largest wind farms [you find my calculations here].
> Take the Roscoe Wind Farm in Texas, which uses 184 m2 per MWh. This is a large project, where farmers can generate additional income through electricity production while they continue their farming operations between the wind turbines. The wind farm is almost a secondary land use. This contrasts with much more dense wind farms, such as Fântânele-Cogealac in Romania, or the Tehachapi Pass in California, where energy production is the primary land use. These can have a small land footprint of just 8 m2 per MWh.
Seems pretty stupid to me. Though if someone get sucked in by the headline, reads the article and moves from thinking "we don't have enough room for renewables" to "there are lots of ways to dual use land with renewables" then maybe it's all for the best.
The UK has a large amount of crop and pasture land, and quite a lot of reservoirs and canals besides. Most places do.
There's no need to be glib, and the GP was obviously talking about the availability of land on a much smaller and more densely populated nation than the comparatively massive and wide open country that is the United States.
It has, in fact, easily many, many times more of both than could ever be needed to share with solar and wind.
It seems like trying to make land do these two sunlight dependent things at once is not as efficient as having dedicated agricultural fields and dedicated solar farms.
You're free to provide them. Call it concern-trolling if you'd like, but I definitely sense you've got a "why don't we just" mindset, where any potential downside is literally a non-issue. You dismiss all concerns and then wonder why something isn't being done when the solution looks so simple.
>"Since solar may use up exactly zero acres, its watts per acre may be infinite."
If it has mass and surface area, it will take up some sort of acreage. Solar panels block light, so obviously anything needing light to survive is going to struggle being underneath them. And, who knew that we could get an infinite amount of wattage out of zero acreage, why haven't those fools designing our electric grid realized this yet?!?
>"But most crops do not, and benefit both from reduced heat stress and reduced water loss."
So you've acknowledged that corn and wheat need full sunlight, but again, it doesn't matter, because in your view solar has no downsides whatsoever. Anything bad is actually good!
>"Please do not make up BS problems."
And you say I'm being the troll here.
You were free to read any of the numerous links provided both in TFA and in comments posted here. Instead, you trolled.
Personally I think they should be put to sea. Along with floating farmland. Just make concrete (or seacrete!) pontoons, connected together into 1000 km^2 islands. Leave the actual land to nature. I concede that is currently scifi though.
When you recognize you have plenty of land that is not being used up by placing panels in it, you can understand there is no need to try to pack panels as closely together as conceivably possible. You can leave room between for livestock and grass.
Open ocean has destructive waves. Panels do much better on calm reservoirs and ponds.
I don't believe you are taking into account just how much location and transmission distance matters for such projects.
If you have some transmission loss, you just add a few more panels.
What's your basis for this? Real-world power grids don't seem to be designed around transmission loss being a non-issue so long as they just 'generate more power' at the source.
Getting coal from a mine to a power station is a big task, so some grids are literally built around the locations of the coal. Hydro and nuclear have similar location needs.
This has changed more recently with gas and renewables where as they get cheaper other factors start to dominate, but the grid was not originally set up for that kind of distributed load and needed some tweaks to adjust I believe.
https://www.energy.gov/eere/solar/solar-futures-study
> Although land acquisition poses challenges, land availability does not constrain solar deployment in the scenarios.
> In 2050, ground-based solar technologies require a maximum land area equivalent to 0.5% of the contiguous U.S. surface area, which could be met in numerous ways including use of disturbed or contaminated lands unsuitable for other uses. The maximum solar land area required is equivalent to less than 10% of potentially suitable disturbed lands, avoiding conflicts with high-value lands in current use.
> Various approaches are available to mitigate local impacts or even enhance the value of land that hosts solar systems. Installing photovoltaic (PV) systems on water bodies, in farming or grazing areas, and in ways that enhance pollinator habitats are potential ways to enhance solar energy production while providing benefits such as lower water evaporation rates and higher agricultural yields.
> Expanding rooftop PV could reduce solar land use. Almost 200 GW of rooftop PV are deployed in the decarbonization scenarios by 2050 (10%–20% of total solar deployment). However, the technical potential for U.S. rooftop PV is greater than 1,000 GW, and efforts to promote rooftop PV could increase deployment beyond the modeled level.
Transmission distance matters when you are talking about sending power 1000s miles from the generation location. For that, you want something like HVDC. However, for anything else, HVAC is good enough.
People greatly overestimate the footprint of solar power, and underestimate the footprint of oil and gas. Every oil and gas well in the nation sits on a 1-5 acre pad that has been scraped flat and denuded of all life. The area that has been sacrificed for this purpose in west Texas and Wyoming absolutely dwarfs the area that we would need to replace that production with PV.
Wind is even a bit more space efficient in Germany. Land use is really not a problem for renewables.
Eminent domain is a common tool to solve this, and it is also used for mining. It is however not very popular.
Land used for rail and roads is used up. Land used for solar may continue being used for whatever else it was doing already.
Please do not make up BS problems.
But most crops do not, and benefit both from reduced heat stress and reduced water loss. Livestock, likewise, benefit from shelter, and the grass grows not less, same reasons.
When you have all of cultivated land available to site solar in, you can choose places to put it where it is most beneficial.
Farm and pasture are not the only places that benefit from shade. Reservoirs and canals lose huge amounts of water to evaporation, and need constantly to fight biofouling.
Roofs, too, last longer in shade.
Maybe a specialized tractor could be built to go around the panels but really you’d want to grow laborious crops that are mostly hand-planted/harvested anyway.
On wheat you may not want to collect too much of the light anyway, because yield might suffer.
Corn is a little harder because it grows so tall. You would need high fencerows, or give up collecting much when the crop gets high.
One merit of these systems is that they produce revenue in fallow years and year-round, while the crops only produce revenue in a spike once a year.
Researchers are experimenting with which plants do best under solar panels and even trying to grow tomatoes and potatoes between rows at existing utility-scale farms, Macknick says.
https://www.reuters.com/business/environment/solar-panels-he...
Solar and wind can be much more opportunistic in using small packets of land.
Or are there examples of more intensive uses under wind turbines?
https://talkbusiness.net/wp-content/uploads/2018/02/Wind-Far...
https://static01.nyt.com/images/2016/07/19/world/windfarms-w...
Just what about these turbines makes farming / ranching more difficult?
just calling everyone a "NIMBY" is not a valid response to criticism of externalities.
The exact blend depends on the location of course, but any sensible grid will likely include both of them (and mixes of distributed solar, onshore, offshore wind). Generally solar and wind should be about 80% of the generation mix, and the precise balance (after including the cost difference over the next few decades) globally leans towards solar being the dominant of the two in most plans and predictions.
edit: this has now made me wonder if anyone calculates the LCOE of 'optimal' solar/wind mix for the region.
The first video has pretty sound (pardon the pun) methodology.
Findings: Unless you're within 200m of a turbine, the background ambient sounds are louder than the sound of the turbine.
Do you have evidence to the contrary?
Their values and systems of belief/reality-building and trust networks are totally different. Successfully negotiating that doesn't mean "my numbers are more correct" but understanding the different subcultures, what's important to them, and being able to respectfully and empathetically communicate according to their needs, not yours.
My primary reason for sharing it was to avoid other (reasonable) people from walking away with some false belief that there might be something to the noise issue. There isn't anything to it.
I'm not trying to convince this person. However, there might be others who don't have the time to do the research. This comment is for them.
People generally like making money with their land, and especially for wind it often doesn't impact the economics of current land use very much. (And even solar isn't necessarily exclusive)
The comparison with rail and highways also isn't very good since for those there are much stricter constraints to cover a useful and practical route in its entirety.
The biggest problem in those situation isn't that the actually land that get used, it is how the farmer get impacted by the rail road being there. If they got a lot of money for those 0.5% with no negative effect then naturally people would have no objection to sell that for huge profits.
I can't speak for your family members or the locations where they are involved, but I do know how much politics there is around where I live. There is a lot of resistance to place wind farms on farm fields, and farmers aren't exactly lining up to rent out their land (or at least not for the price people are willing to pay). Ocean farms are often cited as being easier to build because there is less resistance from land owners and local government.
One land location that does seem a bit easier for wind production are forests in mountain areas which is sparsely populated. The draw side is that the consumers isn't generally located there, so you get the situation where the best and easiest locations to install wind is also the worst location to utilize the production.
(And don't get me started on this, but most arrays are wired stupidly, ignoring what the telegraph and phone guys learned 125 years ago: you want to ground the positive leg, NOT the negative, so you can use cathodic protection via a sacrificial anode to prevent the wires corroding away. You would be shocked how many 10-15 year old arrays I've seen that have something rapidly approaching empty straws of insulation connecting the panels - the breakeven on a solar PV plant is around 20-22 years, so these will never break even!)
Edit: They don't add it to the fuel because they want to. They do it because they are mandated to. Anti-knock properties are just a tiny silver lining that could be obtained through more efficient means were it not for the subsidized ethanol.
> Due to the phasing out of MTBE as a gasoline additive and mainly due to the mandates established in the Energy Policy Act of 2005 and the Energy Independence and Security Act of 2007, ethanol blends have increased throughout the United States, and by 2009, the ethanol market share in the U.S. gasoline supply reached almost 8% by volume
and
> In the U.S. MTBE has been used in gasoline at low levels since 1979, replacing tetraethyllead (TEL) as an antiknock (octane rating) additive to prevent engine knocking.[15] Oxygenates also help gasoline burn more completely, reducing tailpipe emissions and dilute or displace gasoline components such as aromatics (e.g., benzene). Before the introduction of other oxygenates and octane enhancers, refiners chose MTBE for its blending characteristics and low cost.
It is a farm subsidy program, but it also has an actual use. Oil companies went with lead in the first place, despite being well aware of the dangers, because ethanol is also a competitor to gasoline, being a fuel itself.
Yes, Archers Daniels Midland collects a monstrous undeserved federal subsidy.
But unleaded gasoline needs something to raise its octane rating. MBTE turned out to be a public health and ecological disaster. What we use now is ethanol. Probably some other alternative would be cheaper and not burn crop acreage, but wasting corn has been good politics: corn farming states have a preponderance of senators.
Probably naive, what does this mean? There are unleaded gases for sale that are ethanol free at some gas stations (typically only the premium / highest octane) which are often preferred for small motors / high end engines. I don't think they mix in lead, is MTBE what is added instead in those cases? I haven't heard of MTBE before.
ETA: I've been able to find a number of sites for WI gas stations saying "we have ethanol free," but none of them mention what is added in its place (if anything).
https://www.classicfuelsolutions.co.uk/products/classic-fuel...
That's a UK supplier but an answer on Quora suggests 'race' fuels are sold in the US with lead too. Not legal to use on the road though.
> Effective January 1, 1996, leaded gasoline was banned by the Clean Air Act for use in new vehicles other than aircraft, racing cars, farm equipment, and marine engines.
The only leaded fuel you can buy in the US is aviation fuel. You can't buy it at a gas station and the only reason it still exists with lead in it is because that is necessary for compliance with government rules that regulate what fuel can be sold for that specific purpose.
You do get alkylate gasoline, maybe that's what is being sold:
> The availability of alkylate petrol is limited. The actual alkylation process to produce Aspen is a much more advanced and expensive process which only a few refineries in the world can produce. Even if new ways of producing alkylate petrol is developed, regular petrol will still be the dominant type of motor fuel in the world.
https://www.buyrealgas.com/states.html
I found this website, that lists places that sell ethanol free gas, and the number of them that appear to be Marinas, combined with the bit above about lead being used for marine purpsose makes me think they're just using lead.
Somebody call Congress! Think of the children!
Pretty much nobody does this because on the high end race fuels as well as various alcohol fuels are more available and better supported by industry and on the low end ethanol free premium is substantially cheaper. If lots of people did it it wouldn't still be legal. Dumping 100LL into your boat or race car just isn't a good value way to solve a problem anyone has.
> I found several posts from people saying that they buy aviation fuel because they don't like ethanol for their lawn equipment, and presumably people informed enough about the issue to intentionally buy leaded avation fuel would know about other options available).
I hope I'm not the only one appreciating the schadenfreude here. It reminds me of when people unscrew the spout from their crappy compliant cans. Regardless, the overwhelming majority of these people just drag their butt to whatever local station has ethanol free premium rather than go to the airport because it's a faster/easier/cheaper way of accomplishing the same goal.
The current status quo is stupid but the rules are written by a bunch of jerks who either a) DGAF about what happens beyond the next election cycle or b) DGAF so long as they're not responsible and can collect their pension so it's no surprise that the things people do to compensate are non-optimal.
Large tanks are generally okay, but if you try to start a small carbouretted engine after 6mo and haven't drained the tank you'll need to clean the jets and replace the spark plug.
And the first primary or caucus state of the election season is Iowa. The state produces the most corn in the Union and by far the most corn per capita. Large corn subsidies will likely continue until this fact changes.
https://www.masterresource.org/political-capitalism/adm-etha...
> Thanks to federal protection of the domestic sugar industry, ethanol subsidies, subsidized grain exports, and various other programs, ADM has cost the American economy billions of dollars since 1980 and has indirectly cost Americans tens of billions of dollars in higher prices and higher taxes over that same period.
> At least 43 percent of ADM’s annual profits are from products heavily subsidized or protected by the American government. Moreover, every $1 of profits earned by ADM’s corn sweetener operation costs consumers $10, and every $1 of profits earned by its ethanol operation costs taxpayers $30….
It seems like a misunderstanding of both ag subsidies as they exist today and of ADM's business model
1. Lobbying groups for fossils and nuclear trying to find disadvantages of renewables. The most bizarre thing I saw a while ago was arguing strongly for nuclear largely based on the fact that it's more space efficient (saying the importance of that outweighs cost), while completely ignoring the fact that nuclear plants require extensive nofly zones (note theybare not really a problem atm either but would affect how much we can build out nuclear).
2. A strong push for making large scale renewable installations. While it is true that large scale solar is more efficient than smaller scale, I think the prime motivation is that it benefits large operators and investors, not individuals or small communities. Hence the lobby efforts.
In reality just putting solar on most existing warehouses and parking lots would already cover a significant proportion of our electricity use. And others pointed out how solar (and wind) can often be used in dual use environments benifiting both.
https://solarrights.org/
We would get more GW for the buck by using subsidies to really accelerate the expansion of green power generation that is already cost effective without subsidies (solar/wind/pumped storage) rather than throwing money at a form of power generation that wouldnt even exist without subsidies.
If the subsidies were distributed on the basis of stability, GW output and availability then that would be efficient, effective and fair but that would kill off the nuclear industry entirely.
Only one of those choices feeds an exponentially increasing capacity to respond to the crisis.
There are plenty of much lower hanging fruit available than a nuclear plant. Insulation, residential thermal batteries, trains, cycleways, green hydrogen infrastructure, solar water heating, CAES projects, variable load upgrades to aluminium smelters, etc. etc.
I'm all for increasing public spend on green energy, but until there's enough money for the cost efficient things, then nuclear is just helping the fossil fuel industry
Or just do any of the other things on the list I mentioned. Getting 400 commuters out of cars and into a train is an instant 4MW saving.
So the question is: Will you find enough locations that don't annoy the locals and once you found them will your project survive the inevitable intrigues amongst land owners over who gets to rent out their land for the lucrative PV installations?
Even though it's more expensive, I think that using rooftops and other already occupied spaces first is a more sensible route.
It’s quiet and doesn’t smell. It’s about as unobtrusive as you can imagine a thing to be.
If solar panels were more efficient and mass produced in the 1990s, I have to imagine solar farms would have replaced most tobacco farms after the buyouts.
Though maybe I’m biased by my feeling that solar panels are damn-near magic - you leave them outside, basically neglect them, and power just comes spilling out of them.
It is extremely uncommon to site dedicated solar farms within 100m of residential areas.
So let them cultivate a perimeter of just enough forest to hide the panels if it really is a real issue and not a product of NIMBY OCPD.
I spent six years in the utility-scale solar PV industry. You would be shocked to learn how many of the panels are not working in any given array. I've seen everything from almost 10% of the strings not even being connected to the inverters in a utility scale array, to a shocking number of rooftop arrays that were producing nothing. In my entire experience with the company and all its customers, we never encountered a single utility-scale array that was fully working when we arrived on site to add our monitoring or optimization systems, and many of those were brand new!
In one case of a sizable array on the roof of a Texas energy provider here in Austin, we discovered the inverter had died years before we discovered it! (This was field testing of of inverter bus noise effects, and the oscilloscope showed nothing but what the wiring picked up as antennas!) Turns out no one ever looks at the power bills in a power company... :-)
Solar PV actually requires a fair amount of maintenance for both prevention and remediation (cleaning and/or replacing panels, repairing connections/wiring, combiners, inverters, etc.) to ensure they are actually operating, but most owners are happier to cover their ears and eyes and sing, "La, la, la..."
Probably because you took the time posting that you might otherwise have taken thinking. I suggest trying it the other way.
For a certain number of hours in the day, yes. This always strikes me as an odd observation because storage and distribution have always been the more important challenges in our current implementation.
I'd also caution against any form of "monoculture strategy." The lessons from history are pretty clear on this.
All the real estate there you could ever want. 9X the solar flux. Little or no "night". Direct delivery via lasers to any point in the hemisphere.
Where cost doesn't matter, everything gets easy.
The advantages of orbital are nearly 20X generation per panel to start with, even before considering support structures (none) and weather-proofing (none). That leaves lots of room in the cost equation.
Solar panels do not need to be "near major metropolitan centers". Modern transmission lines move power efficiently, silently, and reliably.
It would be impressive for your orbital panels to get out 4x as much energy as the light they intercept carries, but getting a patent on your perpetual-motion apparatus might be difficult.
Maybe do some elementary cost analysis. All the numbers are easy to find. Don't forget to figure in conversion loss from electric power on orbit to laser light emitted, losses scattering in the atmosphere, and conversion again from laser light received to electricity on the ground.
You would better loft many-square-km aluminized-mylar mirrors to reflect sunlight to solar farms on the ground. Keeping them pointing the right direction would be tricky.
Solar flux outside the atmosphere is 9X sea level. Go ahead, look it up. Then there's the periodic eclipse called 'night' that doubles orbital efficiency again. Look that up too.
Conversion losses of 20% seem normal? Both in orbit and on the ground. Which halves what you collect, well within the budget of 20X reducing it to around 10X.
Conversion losses of only 20% from electric to laser, and again from laser to electric again, would be miraculous. 20% scattering loss in clear weather would be unsurprising. 90% loss, total, would be admirable, not counting the original 60%+ loss off the top. So, even with 9x, and neglecting huge launch cost you still come out behind.
So about 75% of solar radiation reaches the ground. In the continental US, factoring in angle of the sun, average weather, night that comes to about 4-5KWh per day
In orbit you would have just 1.37KW X 24 hours (no weather, angle issues) which comes to about 33KWh per day. So that's 8-9X the collected energy per square meter in orbit vs ground level.
These folks https://www.allaboutcircuits.com/news/wireless-power-transmi... estimate 89% efficiency from orbit to ground.
So we're then at around 30KWh effective.
What am I missing?
So many things. The massive clear area around your receiver. Scattering induced by weather means you still don't have 100% capacity factor. With only radiative cooling available, cooling will take up as much space as the panels and make everything heavier. The atmosphere doesn't absorb light uniformly. Maintenance. You're comparing fixed panels at mid latitudes to rotating panels. Launch costs are still 10x the cost of a panel. UV and ionizing radiation will destroy your panels sooner. And a space borne panel will probably never reach net energy payback even before you add your laser boondoggle.
You're better off just burning the methane.
The land-based panels are 42lbs for 450W. The space-based ones are 6W per gram. Lots of room in the equation for cooling.
The 89% transmission already figured in weather and absorption; you don't get to count that twice.
Rotating panels get what? 25% better? Still an order of magnitude improvement.
Launch costs are dropping like a stone. Plan now; it'll be in the hundreds of dollars when you launch.
The slang about 'it'll never pay' is just talk. I'd hoped for some information, not just wet-blanket doubt.
Like the hot air about 9X being so far from the truth. Turns out, it's just about right. So I guess I'll have to look elsewhere for more information.
Somebody will make an orbital station, use it for space-based operations and all the hot air will disappear. And not that far in the future.
Land area is an absolute non issue for solar. With the exception of somewhere like luxembourg, just the roofs of the residential areas of a country have enough area to provide the total primary energy consumption. The singular and overriding factor is cost and cost of storing or moving the energy. Which brings me to
> The land-based panels are 42lbs for 450W. The space-based ones are 6W per gram. Lots of room in the equation for cooling.
You're not going to get nameplate capacity, and the weight is in the superstructure, cooling system, power delivery, and your 100s of metres aperture laser or maser. The actual panel for a terrestrial caravan system I installed recently weighed no more than the panels listed here https://www.spectrolab.com/DataSheets/Panel/panels.pdf (although it was bigger).
So you're proposing spending 10x as much on panels, another 10x as much on cooling, spending as much again on a transmitter, then as much again on a receiver. All to burn tens of kg of methane per watt in order to get the thing into a stationary orbit. Then you have a gigawatt death beam fucking up the atmosphere and making a square kilometer or so uninhabitable.
> Like the hot air about 9X being so far from the truth
Comparing like for like, you have about 1.3kW in space vs 1kW on the ground, and a tracking setup can get 6kWh/day out of a 1kW panel at low to moderate latitudes (where well over half of the world's population lives). This is a factor of 5 to 6 better, although your space based panel is vastly more expensive and a tracking system is pointless because cost is the limit, not area.
This is the most efficient high power long range wireless transmission system I can see mentioned: https://ietresearch.onlinelibrary.wiley.com/doi/full/10.1049... which brings the ratio to around 3-4. Except you also have to deal with losses due to clouds and dust so 2-3 is more likely.
At that point just build a nuclear plant. They're awful but they're better than this plan by every metric. Or do the sensible sane thing and build 100x the terrestrial solar for the same price (or 10x as much and enough storage) and save the space arrays for stuff in space -- once you're lifting megatons it makes far more sense to refine metals from asteroids and just leave 99% of them up there.
Or as I said, just burn the rocket fuel in a gas turbine. You'll get more energy out of it than you would from this utterly ridiculous machine in its lifetime.
If area was a constraint important enough to make space based solar viable we'd see water cooled triple junction cells as well as tracking on any utility scale installations near the equator (as this would reduce area by 2/3rds). We don't so it can be safely dismissed as more solar frickin roadways.
Orbital power is a total nonstarter if we aren't building the panels in orbit. Launch costs will absolutely destroy any ROI, even before you get into the transmission losses beaming the power back to Earth. SpaceX has completely revolutionized the launch industry, getting costs down to around $1200/lb. A typical solar panel weighs about 40lbs, but aren't optimized for weight. Assuming you can reduce this to 20lbs per panel that's still $24,000 per panel not counting transmission equipment and the like. The panel itself costs maybe $2000 for a very high efficiency model. The launch costs dwarf the panel costs, even when accounting for the lack of weather in space. It just doesn't make sense, especially when you start adding in all of the additional costs like building the satellites, the ground stations, transmission losses, fuel to keep the orbits from decaying, the fact that you won't be able to send these to Geo Orbit without incurring crippling transmission losses, so you'll need a lot of ground stations, etc...
Compared to all of that, the problem of finding parking lots in the suburbs seems absolutely trivial.
Also your design sounds suspiciously like a GDI Ion Canon from Command and Conquer[0]. Imagine having dual-use concerns like we do with nuclear power.
[0] https://imgur.com/a/T8IDs2h
No matter what kinds of launch cost improvements you predict (including, of course, Starship-likes), it will always be orders of magnitude cheaper to just build an array here on earth that is 3-4x larger than to lob anything into orbit.
The Microwave/Laser power transmission schemes of orbital solar are also a huge problem, and in all likelihood would never make it through any kind of environmental impact study, much less an engineering effectiveness/reliability review. (Not to mention that, like the famous laser drive in Larry Niven's Man-Kzin wars, any laser/maser/microwave array that large is inherently a formidable weapon of mass destruction, with no modification other than repointing it....)
Technology moves on, but old wet-blanket excuses live forever.
https://arxiv.org/pdf/1905.08024.pdf
https://boeing.mediaroom.com/2010-11-01-Boeings-Spectrolab-P...
https://www.spectrolab.com/photovoltaics.html
And, the important efficiency measure is W/$, where GaAs trails well back. Perovskites may exceed 40% conversion efficiency, and also have good prospects to offer much better W/$. Their endurance has grown encouragingly quickly.
W/$ goes down with manufacturing efficiency. Nobody has done large scale manufacturing of multi-junction GaAs cells.
Top-end GaAs technology wouldn't compete with bottom-end silicon technology (the below-16% panels that you mention). It would compete with top-end silicon technology, which is already commercially available at module efficiencies above 22%:
https://cdn.energypal.com/panels/spr-x22-370/energypal-solar...
Note that the upper cell efficiency limit for any single material under incident terrestrial sunlight is about 33.5%:
https://www.energy.gov/eere/solar/multijunction-iii-v-photov...
GaAs cells reported to operate above this limit are part of multi-junction cells and/or incorporate optical concentration systems to focus sunlight to higher intensities. The experimental record-holder of 47.1% uses a multi-junction cell plus optical concentration. Optical concentration only works with direct normal illumination; light that is scattered through haze or clouds can't be focused, so optical concentration systems are a good match only for sunny areas that have clear skies year-round.
That said, the National Renewable Energy Laboratory is researching ways to make GaAs cells at lower cost:
https://www.nrel.gov/news/video/building-low-cost-high-effic...
At low enough cost, GaAs modules could compete directly with premium silicon solar modules. They could conceivably be lighter as well as more efficient than silicon, since thinner layers of GaAs are needed than silicon layers, which in turn reduces the required module rigidity, thickness, and weight.
Certain uses place a premium on areal efficiency, notably aerospace.
But anybody who has maxed out their own collection area, whether a roof or reservoir, can get more revenue from using better cells. And, the more of that that is done, the faster their price falls. We may reasonably expect the price of multilayer perovskites to drop below cost of silicon panels. Sooner is better, which is driven by maxed-out demand.
I guess this makes sense given the hard bit is the substrate.
This would be good for everyone as second hand silicon cells for 10-30c/W will open up a bunch of new uses.
Why is it that Trees can generate more energy via absorbing light than implied by the surface area of leaf coverage of the outer branches?
Hint, yes has to do with light spectrums and their behaviors and the benefits of chloroplasts using more than one light frequency
Really the only downside is that people will crash their cars into the support structures. It is inevitable, and needs to be accounted for in the design.
From the gas and oil companies' perspective, with enemies like these, who needs friends?
The issue is really mostly the difficulty of smoothing production over consumption. And transmission.
Some companies do Time of Use contracts which do this to a degree, but flat incentives (cut a one time check to the homeowner) seem much less complicated. The grid gets smoothing and the homeowner gets to keep the lights on when the power goes out and doesn't have to spend nearly as much on the install. The power company doesn't have to manage a big bank of batteries somewhere and saves on distribution costs. Plus the homeowners technically own the systems so when something goes wrong the power company doesn't have to roll a truck to fix it.
The only real problem with this scheme is that the battery market is already squeezed with so many companies jumping into the electric vehicle business and production lagging behind demand. However, this is likely to be a short term problem, so hopefully in the next couple of years something like this will be practical.
The batteries may be identical but installing them, monitoring them, doing AC>DC>AC conversions etc become much cheaper at scale.
A sharing program foists most of this complication off on homeowners.
https://www.greentechmedia.com/amp/article/from-pilot-to-per...
The general term is Virtual Power Plant, where software let's a bunch of distributed items act in concert as if they were a big powerplant.
1) Heat kills PV efficiency, since, to a first order approximation, current is proportional to irradiance (deserts good), but voltage is inversely proportional to temperature (so deserts very bad). You make way more power on a clear winter day in Colorado (assuming no snow on the panels!) than you do on an Arizona summer day. If you don't like this, take it up with God, since it's just the way he built the universe and the quantum physics of semiconductor junctions.
2) Dust (and/or salt, if you're anywhere near the ocean) is a huge enemy of solar power production (so deserts bad, again). Dust or salt spray can easily cost you nearly half of your power output. PV panels are scarily susceptible to even small shading from leaves or even bird crap on them. I can throw a business card on most panels and take out 1/3 to 2/3 of that panel's output. If wired in a string, as is typical for utility scale PV, the loss of that single can take out the power production of that entire string (typically 12-22 panels worth), since it can no longer reach the inverter bus voltage set by the unimpaired strings.
Oh, and cleaning panels is really expensive - it was $0.50/panel a decade ago when I was collecting the largest database of DC solar panel data in the world - I don't imagine it's gotten any cheaper... (One of the big selling points of our software was that it could optimize cleaning and maintenance timing and intervals. This can actually make the difference between breaking even on the array cost or not!)
Wait, how does this shit even work at all, then? Are solar farms just perpetually functioning at <50% capacity because everything broken all the time?
Bonus if you use that heat to generate more power at night.
What we should be focusing on is transmission and distribution, those are the really hard problems. We could have all the power we want but if our grids can't handle the rapidly increasing demand it does nothing for us. And as more people go 100% electric for transportation, heating, and cooking the integrity of power distribution becomes even more important because we will have put all our energy eggs in the electricity basket.
The only place land use seems relevant is for smaller scale off-the-grid cases where someone's property is small but they want to generate all their own electricity.
1. In small(ish), densely-populated countries, land is in short supply, regardless of any socio-economic-political considerations.
2. In many countries, land is private, or has been fully "divvied up" in some form or another, despite being only sparsely used. In these countries, reallocating land is a headache - politically, economically and legally.
But I agree that storage, transmission and distribution are important things to focus on. Or rather - the important thing to focus on is to actually deploy lots of solar instead of fossil (which the recent US federal legislation makes even harder than before).
Why?
What do you think, expect or hope this will accomplish?
Because the technology is in good enough shape already to partially replace fossil-fuel-based production - at least in day-time. Some might even claim that it can replace fossil-fuel-based energy production in daytime entirely, and with existing storage tech, perhaps even mostly-replace it in night-time. But the first claim is sufficient and AFAICT pretty much in consensus.
> What do you think, expect or hope this will accomplish?
Significant reduction in greenhouse gas emissions by burning less coal and natural gas.
Secondary potential goals:
* A motivation to switch to synthesized car fuel / fuel cells / electric.
* Improvement in air quality around where coal-fired plants operate now.
Having and living with solar is very different from what people imagine solar to be. Here's a simple example from my 13 kW array:
https://i.imgur.com/SOr30bX.png
or
https://i.imgur.com/yvTdNX0.png
What are those massive dips sometimes causing a reduction of output of more than 50%? Clouds. Simple as that. This is what a "normal" clear-sky day looks like:
https://i.imgur.com/Fl8ARJd.png
Output like that is frequent but not the norm. Clear sunny days in Southern California. If you live somewhere with more weather than we have here, it will be more like the first example.
The consequences of weather are severe. Here's a look at January of this year:
https://i.imgur.com/bGuCH2F.png
And here's a look at all of last year:
https://i.imgur.com/EF2L3Hk.png
This is to say at least two things about the reality, vs. the fantasy, of solar:
First, the technology isn't reliable. Not inherently, of course, the power output reliability is a function of weather. And we can't control that. I can't think of a single place on earth where there aren't any clouds, rain, fog, storms, dust, etc. Note from the images I provided that my 13 kW array never really peaks out at 13 kW. I think the most I've seen is 11 kW. You would need an absolutely perfect day with perfectly clean panels to, maybe, reach a higher peak for a few seconds.
Also note where the annual production peak is located, May. Most people think solar peaks in the summer. Not so. Panels have a negative temperature dependency. Which means they make less power when they get hot. May, here, happens to be the balance point between incoming light and lower temperatures.
Having built and operated this system for a number of years, here's the biggest problem with solar as I see it (and this isn't something trivial):
In other words, if you want a solar power plant that can deliver 1 MW (Mega Watt) 24/7, you have to install about 10 MW of solar panels and a massive storage system.I've done the math on this multiple times, it's undeniable. Some of it is very simple and some of it requires basic high-school calculus. Here's a couple of examples:
The area under the roughly parabolic shape of normal (ideal day) production is 2/3 of that of the rectangle that would represent steady-state power at the peak level for those 12 hours. In other words, you start to produce at, say, 10 kW at 8 AM and stay at that level until 8 PM.
That simple reality means that, in order to produce the same energy of a steady 12 kW power source you need to multiply your system size by 1.5. In other words, if you need 10 kW x 12 hours of energy, you need to build a 15 kW system.
The next easy to understand reality is that you need to double that system (at a minimum) in order to have that much energy available at night. Now we go from a 10 kW system to a 30 kW system plus the corresponding amount of storage.
Another easy one is inverter (and related components) average efficiency. I'll place that at 90%. That means you lose 10% just to make power you can use. It also means that we now need to add solar panels in order to achieve the required output. That...
I live in Oregon and slightly over 1/2 of the state is federal or state owned land which cannot be purchased. Even out in the middle of nowhere, there are still massive transmission lines carrying electricity from one part of the state to another through these areas. This is often in fairly mountainous terrain and dense forests. I'm often in awe at how much work they have to go through to keep the area immediately around these lines clear of trees and vegetation. I explore forest roads quite a bit. This is just to point out that we've been doing that type of thing for a long time and I don't think transmission itself is tremendously difficult. We just lack the will.
There are some challenges with transmission, but I think the bigger ones isn't necessarily building the infrastructure -- it's making the transmission lines themselves more efficient and reducing losses. We can't build all our solar in the southwest of the US and then distribute that all over the country; Our current transmission technology would produce too much loss over such distances.
Impacts to watersheds are the biggest environmental issues of any small or large scale building projects in my neck of the woods. I’m only allowed 12 percent of my land for impervious surfaces.
"EMLR allows solar panels associated with ground-mounted solar farms to be considered pervious if they are configured in accordance with the recommendations in this chapter. These recommendations promote sheet flow of stormwater from the panels and natural infiltration of stormwater into the ground beneath the panels."
...
"In general, the minimum disconnection length between two rows of solar panels is equal to the width of each row, as shown in Figure 1. However, some panel layouts include horizontal gaps between individual modules that allow stormwater to drip off the panels at intervals much smaller than the width of each row. In these instances, the solar farm can be designed with a smaller disconnection length, provided that they will not cause concentration of stormwater runoff."
https://deq.nc.gov/media/12043/download
Consider tokyo as an example of a space where area is at an absolute premium. There are around 7000 people per km^2
Shrink it down to a single block. Tokyo's blocks are a little smaller, but a common size is 100x200m for ease. At 0.7kWh/day/m^2 there are 14,000kWh/day available in this area shared between 140 people. This is about 100kWh/day each.
This isn't quite enough to be as absurdly wasteful as someone from Australia or the US, but it covers the total per capita energy consumption of people living pretty much anywhere else.
Note that this is just the net solar electricity available in a high density metropolis as an input vs all energy (including thermal) used everywhere.
As soon as you add in medium density towns or industrial areas there is an abundance of space for panels so long as we stop being exponentially more wasteful with the available energy.
Anyone bringing it up is a fossil fuel or nuclear shill.