When I last priced out a solar panel install on my house a few years ago the cost came to something like $20K, and the capacity was quite modest - only the most favorable slope of the roof. There simply was no way for me to recoup the investment, ever, even ignoring maintenance costs (those panels need to be cleaned from time to time). It's probably lower now, though I wonder if the cost differential is significant - much of this cost is labor and margin.
I wonder if this was communicated to those responding to the poll. In SV and SF $20K might not seem like much, but not all of CA is that well off.
Your investment is recouped in 8-13 years (depending on state; the more expensive your power, the faster the system cost is recouped), after that the system produces power "for free" [1] [2] and the components (panels, inverter) are warrantied for 25 years. Panel cleaning is spraying the panels with a hose.
The best time to get solar is when a house is built, or a roof is replaced, especially if you can combine the install with a financing event that's going to let you finance the system for 20-30 years with low interest rates. Not only is there a 26% federal tax credit for solar, but many states offer generous incentives/rebates as well. Capture them!
It's fiscally a no brainer. $20k over 30 years at 4% is $95/month. Mortgage rates will only continue to go down (and are already below 4%) due to macro issues, and residential solar install costs also will drop as the scale ramps. These mandates drive down costs, in the same way EV credits helped Tesla reach scale to offer the Model 3 at an affordable price.
Disclaimer: I review system quotes and advise on solar installs for friends, family, and internet strangers, but am not a solar professional (yet; if you're a utility scale developer in need of any role [system design, project management, finance], I'd be interested!).
All of that depends on your power costs. My town has its own municipal power cooperative that buys very cheap hydrothermal electricity. Solar would never make sense for me, except as some kind of disaster-event alternative.
I mention that in my comment, and I agree that it doesn't make sense in locations that have sustainable renewable power (hydro in the PNW, geothermal such as that in Iceland) in place. It makes sense anywhere attempting to phase out fossil (coal, gas, shale) or older low carbon tech reaching the end of its useful life (nuclear).
For example, ComEd in Illinois is offering incentives on top of state and federal incentives for rooftop solar due to a state renewables mix mandate, and their fleet of commercial nuclear reactors are reaching the end of their service life (and aren't cost competitive with wind and solar in the state, even accounting for the need for battery storage to meet capacity requirements).
Electricity my state is 11 cents a KWh, and most of it already comes from hydro. Your calculation only holds if the owner plans to live 30 years in the same house, which I do not. You also ignore the maintenance cost. Every spring everything in my area is covered with a layer of yellow pollen. There's also snow sometimes, and general lack of sun for 6 months in any given year.
There was actually a humorous episode when a guy from a solar installer came to our office to advertise how much economic sense their solar panels make. He gave all the exciting numbers and everything, and then someone asked him to show some numbers from an actual installation, at that particular time of day. So he brings up a web GUI for a 50KW commercial install, which at the moment was producing something like 2.5KW. Awkward.
Ultimately, though, that's not why I didn't go with solar. Our HOA doesn't allow it. I would actually welcome a law which would limit the HOA's say in such matters, or eliminate it entirely.
I'm not ignoring the maintenance cost, I'm saying it doesn't exist. I'm also saying the math works already in your state at your energy cost. If you want to argue, let's argue over facts.
I'm not sure what state you're in, but several states prohibit an HOA by law from preventing you from installing rooftop solar. You should check if your state has such legislation, and if not, champion it. I'll even do it for you if you don't want to spend the time (until I can get federal legislation passed).
Top hit on Google: "Solar panels generally require very little maintenance. They are very durable and should last around 25-30 years with no maintenance. The only maintenance you should need to perform is to wash them clean of dirt and dust two to four times a year, which you can easily do with a garden hose."
Sounds expensive, if panels are installed on the roof. And you can't wash off pollen by just casually spraying it with a "garden hose".
HomeAdvisor quotes $100-350 a pop. As a homeowner I'd expect the actual cost to be closer to the upper end of the range. Tradesmen won't get out of bed in the morning for less than $200. To wash windows in my house from outside only is $300.
Thanks for pointing out that I corrected my information, I prefer communicating accurate information. Panels and inverter have 25 year warranties. Storage is optional (the 10 year warranty you mention). If there are incentives for it, get it, but don't pay out of pocket entire yourself for the storage. Let state, local, and utility pockets pay for it.
Was that from an installer? That's about what I was quoted, but if I do the legwork (building permits, hire installer and electrician), it's under $10k before incentives for a decent system (~4kwh).
I pay ~$50/month and that would offset most of my bill (net metering resets at year end, so I'm likely to pay most of Jan+Feb), so it should pay for itself in 10-15 years, probably closer to 10 since my numbers are very conservative (low estimate for electricity, high estimate for installation & parts, low electricity cost). Panels are under warranty for 20 years, and they immediately add value to my house, so it's a net win as soon as they are installed.
Maybe it's one of those "not my problem, it's free to me". As most people aren't thinking of themselves spending tens of thousands of dollars.
The economics of a mandate is the scariest thing. I imagine shortages of natural resources and production. It will further divide the 10% and everyone else.
One thing proponents of ideas like these miss is Solar is very geographical - this is clearly a good idea for California, West Texas and American South West - but pretty much bad idea for the rest of the USA.
Again, Solar panels do not grow on trees and their manufacturing process is chemically intensive. So, it is in the best interest of every one, that Solar PVs are deployed where they return both economic and environmental value.
Again -- here is the link to Global Solar Atlas --
Germany doesn’t have a housing crisis. The context of the mandate is that USA lacks about fifteen million houses that it desperately needs. Solar power adds tens of thousands to the already-bloated cost of construction.
Don't build a house if you can't pay for the energy it's going to consume. You still come out ahead (versus utility power alone) if forced to pay for solar on the roof, and finance the system cost as part of your mortgage.
Americans aren't entitled to the cheapest new construction housing possible while foisting the consequences of that on the rest of us. No different than cars being more expensive to meet higher CAFE mileage standards. Not living in a polluted hellscape costs money, who would've thought.
Meta: Where did this entitlement complex come from that someone's pocketbook is more important than the air we breath?
I don’t know why you’re accusing me of having an entitled attitude. I worked to develop two of the largest solar power stations in California. And I happen to know that utility-scale solar makes a hell of a lot more sense that rooftop.
If you’re worried about pollution tax the emissions, like any civilized country would. Mandating rooftop solar is way too indirect and exposes the public to corruption of the construction trades. Of course, that’s why the parties that stand to benefit from the corruption are going around the country pushing these laws.
I'm not accusing you directly (that would be rude), but the idea in general when someone says "this makes housing more expensive!". It doesn't make the total cost of ownership more expensive, but it does front load some of the energy costs while still being cheaper in the long run for the homeowner. In some jurisdictions (California, the sixth largest world economy), it's been deemed a reasonable policy strategy.
Utility scale makes sense, but so does rooftop solar at scale (if you can streamline soft costs; permitting is unnecessarily expensive AF in the US versus someplace like Australia). A pollution tax will take time to implement, if at all tenable in American politics. Unfortunately, indirect methods are needed at times due to the political landscape. I will take a decent solution today over the perfect solution when it's too late.
California’s mandate has already been postponed over the objections of several municipal utility districts and probably will never take force in the way people who drafted it expected.
I really think mandates like this are totally wrong approach. Consider that in virtually every jurisdiction in California a new home requires both solar power and a 2-car garage. If that isn’t perverse I don’t know what would be.
Unlike you I consider a carbon tax almost trivially easy to implement. Way easier and more effective than construction mandates.
Agree to disagree. If a carbon tax was trivial to implement, why is it not implemented yet? If not now, when will it be?
Utilities can kick and scream (and attempt to subvert the mandate to maintain their relevance), but the mandate will go into force.
> Commission officials acknowledged homeowners will see smaller bill savings under SMUD’s Neighborhood SolarShares program than they would with solar panels on their roofs.
> The average single-family home in the utility’s service territory, which covers most of Sacramento County and parts of Placer and Yolo counties, can currently save around $75 a year with rooftop solar, the Energy Commission estimated. Under SMUD’s program, the average single-family home will be guaranteed electricity bill reductions of just $28 a year.
> The changes from SMUD’s initial proposal didn’t convince critics from several prominent environmental groups, including the Sierra Club and the Center for Biological Diversity. They argued the solar projects SMUD plans to use for its program are too large and generally too far from residential neighborhoods to be considered true “community” solar facilities.
“ California Energy Commissioners gave the Sacramento Municipal Utility District unanimous clearance to offer builders the option of buying solar energy from SMUD, via local solar farms SMUD would build, rather than install solar panels on new-home roofs.”
I think we're destined to remain on different sides of the argument. I'm confident rooftop solar still wins; utilities aren't known for not raising rates, and the political winds shift. It might take longer, but rooftop solar keeps getting cheaper every year. SMUD provided power from natural gas [1] doesn't, regardless of how much local utility solar they build. They even call their natural gas a renewable resource!
We need both. Utility scale solar has it's own set of problems related to land use. There is nothing about rooftop solar that makes it make less sense than utility scale if it's done well. There is a promising future ahead of us where building regulations will take into account cosine losses and start mandating equatorial facing rooftops, solar trackers, etc. It just seems weird now because we haven't seen it done yet with any kind of aesthetic vigor.
By the way, it's not commonly acknowledged but in my experience solar panels are very underrated as effective insulators, reducing A/C costs.
Well, if you look from the outside, the USA seems to have a huge problem with the construction of houses in general.
Start building houses out of bricks and mortar. They will last for a century, provide shelter to your children and grandchildren and in that case, 10k for a solar system do not really make much over the time.
Indeed, almost the whole of the USA housing stock is disposable hovels. The real problem is we don't replace them, we instead give them historic protections!
First question: How much of the cost of a house is the cost of the land, and how much is the cost of the construction?
Second question: if the PV is part of the construction, and not bolted on afterwards, what can you save?
Third question: given that these save money and are a net economic win after a decade even when they are bolted on as an afterthought, even if the answer to #2 is “none” and even if the answer to #1 is that purchase prices go up rather than land owners can’t sell for as much, surely it’s still a win?
I calculated how much it would cost for me to DIY av solar setup, and it was <$10k to completely offset my electrical bill. To get a solar installer to do it, however, was ~2x the cost (best offer from multiple installers). If you're building a new house, it's going to be fairly inexpensive to install solar during the process since you can just include the permits and whatnot in the initial construction.
That being said, I'm against a mandate. Solar panels look ugly, so sometimes it's preferable to have the energy company take care of it. It also requires a decent amount of additional equipment, which means certain types of additional risk.
Instead of this type of legislation, at should just tax carbon and let individuals optimize. If fossil fuels become ~2x more expensive overnight, you can bet we'll transition to green energy much more quickly, but it doesn't push a specific solution. Maybe roof mount solar isn't the best option but some other centralised energy solution is (e.g. nuclear or wind).
The idea that solar is guaranteed to be an environmental or economic net-negative in the northern US is misinformed at best, propaganda at worst.
Just as a single data point, my parents, who live in rural upstate NY, installed solar panels on a portion of their (connected-to-the-house) barn's roof a few years ago. Aside from times when they're literally covered in snow (which is rare, due to their temperature), they're producing power, and even in the depths of winter they produce plenty enough to offset a huge chunk of their electric bill (and in the summer, there are days and weeks at a time where they're producing more than they need).
I can't speak for the specifics of environmental impact, because I don't know the details for their panels, nor how one calculates such uneven things (how do you subtract electricity generated from the various kinds of environmental damage done to mine and refine the various rare minerals in solar panels...?), but at least economically, they're a huge win.
The area covered by the solar panels is roughly comparable to the size of one side of a typical roof in their area—and the area is mainly middle- to lower-class.
Every energy solution in existence. Whether nuclear, steam, hydroelectric, solar or coal. Was manufactured from raw materials that were mined and refined. It makes no sense for you to single out solar as if it exclusively were the only energy source this precedent relates to.
No, it's not. As already pointed out, Germany is full of PV, even very large systems.
Deploying solar systems everywhere is very important to decentralize energy creation (and in the future: energy storage). The future of our electrical systems lies in decentralized systems, to minimize the need for huge infrastructure to get power from A to B and also to "harden" the grids against failures.
So, it's a good idea to have solar on every house. And if it only takes care that your fridge is running on "your own" energy from the PV system that's a good start as well.
I don't support this mandate because it's a one size fits all rule. Do we really want Alaskans and Mainers to be forced to have solar? Why not mandate low carbon energy and then let technologists figure out the cheapest solution for each new home? This would be far more cost effective and limit emissions far better.
Or better yet, just tax carbon sources. If your energy bill doubles over night, you will be interested in solutions, and maybe solar isn't the ideal solution in your area.
Wouldn't batteries on new homes make more sense? If we can smooth peak demand we can lower carbon emissions much more than we can by producing power during solar hours.
Batteries do make sense in some situations where you have large amounts of renewables available on the local grid, and parts of Australia and California are paying homeowners incentives for installing local storage. They make less sense immediately in places where you have hydro and nuclear as base load along with renewables; the capacity factor is already accounted for, so you'd want to prioritize anywhere you could displace fossil generation (such as natural gas).
Tesla is also pioneering virtual distributed load systems, where they can have a utility send a signal similar to that used to shed AC units during high consumption periods, but the signal is instead used to command vehicles to charge when there is excess energy on the grid. [1] This would make sense today in places like Texas, that have so much wind energy (and not enough transmission capacity to other load centers) some utilities provide you electricity for free at night. Any KwH you can use instead of curtailing is a KwH of energy you're not wasting.
Works for single-family dwellings, and maybe duplexes. But a 4-story apartment building with 2 units on each floor? Same rooftop, 8X the electricity demand.
If a city wants more solar, then they could put up a solar farm in some rational place with a good economy of scale, and connect it to the grid.
So much this. If you’re building anything in an urban setting that actually has enough roof to power its dwellings, that just means it’s not tall enough. PV mandates miss the point that it is dispersed, detached developments patterns that are inherently energy-intensive. PV doesn’t fix that.
For example, one person in a 50 m² apartment, divided by 4 floors, with 20% efficient panels, 25% duty cycle for night/latitude, still implies 625 W/person. That won’t power everything all the time, but it would reduce the required size of the external electricity source — be it PV, nuclear, fossil, whatever — by a decent amount.
Swings and roundabouts. There is also benefit in using the PV as the roofing material, and also in pick one of {reduced transmission losses; minimising the land use of those solar farms} — land near a city is almost always at a relative premium.
The city is doing it. If they can mandate every house to have solar, they can use eminent domain to get the land. Which would also be more efficient.
This whole rooftop solar movement reminds me of 'solar roads', a snakeoil scheme a couple of years ago. It has no rational basis, and no compelling engineering support. Its just a 'roofs are flat; solar panels are flat; hey! lets put solar panels on rooftops!'
E.g. does the rooftop have an appropriate southern exposure? Is it in direct sunlight? Does it have the carrying capacity for tons of equipment? Is it a safe place to do construction? Will the roof's normal function be unaffected by solar installation?
First, I thought eminent domain allowed a government to force a sale, not that it forced the seller to do so below market price. I’m not a lawyer so I won’t argue that.
Second, even if all the things you’ve just said “no” about are true for 100% of existing property, if this is part of the planning regulation for new buildings, then the designs can be required to be such that the answers are “yes”. I know this is technically achievable by way of having at least one example of PV on a roof.
Again, no. Houses shade one another; apartment buildings can shade hundreds of houses. Mandating every home be solar is nonsense, in any practical deployment.
And again, one roof for many families doesn't scale. A solar farm has every advantage over this scheme.
> apartment buildings can shade hundreds of houses
Do you think that isn’t obvious? So keep new apartments away from houses and vice versa. So what, no big deal.
The idea is called “planning permission” and why sewage plants are not normally next to residential areas.
Problem solved a very long time ago — which is convenient, because this is the exact same problem you’d have to deal with when planning the solar farm in the first place, because the apartments can shade solar farms too if they’re built too close.
> And again, one roof for many families doesn't scale.
Not claiming it scales with arbitrary height. It’s clearly constant with arbitrary height. Claim is that it’s still useful for ~4 stories with one family per story.
> A solar farm has every advantage over this scheme.
Except for land cost, grid capacity including connecting to the farm to the grid in the first place, and the money rooftop solar saves on the cost of the roofing material, and the way local power generation at least enables the possibility of power when the grid is down like happens sometimes in CA fire season, and the way this puts more money in the hands of normal people whereas a traditional solar farm or power plant will put it in the hand of shareholders, and the fact that large land use changes have their own ecological issues and NIMBYism (remember, if we suppose that the rooftops don’t cover enough area, then the solar farm you want to build is larger than the combined area of every building in the city it’s associated with), and the way rooftops get built every time a residential building gets built so in the case of houses it will scale perfectly with population when a PV farm or an apartment won’t. (Apart from that, what have the Romans ever done for us? Etc.)
Edit:
Just to be clear, if you were to say “American building codes make rooftop PV needlessly expensive”, I’d agree with you. My in-laws and parents both had PV installed in the UK, and even a decade ago it cost them less than half of the prices I see quoted on HN for American rooftop PV today.
However, this an entirely separate argument to the one you appear to be making.
99% of Americans, and almost all people in the world, are wholely unqualified to make any meaningful decision that basically makes most forms of affordable housing unlawful.
If this sample is, by some miracle, representative; I guess it shows that Americans must live amazing middle-class lives to believe that this policy is viable.
This may be off-topic, but I've had a passing thought over the years of the evolution of opensource to expand to the blueprints, architecture and building-codes of residential homes to simplify the upfront costs and options of new construction for specific needs (starter homes, bachelor pads, tiny homes,etc).
In the US for instance, could we take all of the local building-codes and design blueprints that would satisfy all of the legal requirements for quality, sustainable construction, regardless of the state, city or county that you choose to build in?
Even going with a smaller scale and offering off the shelf blueprints by state may stimulate more new construction growth and sustainable designs.
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[ 3.4 ms ] story [ 125 ms ] threadI wonder if this was communicated to those responding to the poll. In SV and SF $20K might not seem like much, but not all of CA is that well off.
The best time to get solar is when a house is built, or a roof is replaced, especially if you can combine the install with a financing event that's going to let you finance the system for 20-30 years with low interest rates. Not only is there a 26% federal tax credit for solar, but many states offer generous incentives/rebates as well. Capture them!
It's fiscally a no brainer. $20k over 30 years at 4% is $95/month. Mortgage rates will only continue to go down (and are already below 4%) due to macro issues, and residential solar install costs also will drop as the scale ramps. These mandates drive down costs, in the same way EV credits helped Tesla reach scale to offer the Model 3 at an affordable price.
Disclaimer: I review system quotes and advise on solar installs for friends, family, and internet strangers, but am not a solar professional (yet; if you're a utility scale developer in need of any role [system design, project management, finance], I'd be interested!).
[1] https://www.solarpowerrocks.com/wp-content/uploads/2016/12/s... (updated 10/23/2018)
[2] https://www.solarpowerrocks.com/
For example, ComEd in Illinois is offering incentives on top of state and federal incentives for rooftop solar due to a state renewables mix mandate, and their fleet of commercial nuclear reactors are reaching the end of their service life (and aren't cost competitive with wind and solar in the state, even accounting for the need for battery storage to meet capacity requirements).
There was actually a humorous episode when a guy from a solar installer came to our office to advertise how much economic sense their solar panels make. He gave all the exciting numbers and everything, and then someone asked him to show some numbers from an actual installation, at that particular time of day. So he brings up a web GUI for a 50KW commercial install, which at the moment was producing something like 2.5KW. Awkward.
Ultimately, though, that's not why I didn't go with solar. Our HOA doesn't allow it. I would actually welcome a law which would limit the HOA's say in such matters, or eliminate it entirely.
I'm not sure what state you're in, but several states prohibit an HOA by law from preventing you from installing rooftop solar. You should check if your state has such legislation, and if not, champion it. I'll even do it for you if you don't want to spend the time (until I can get federal legislation passed).
Top hit on Google: "Solar panels generally require very little maintenance. They are very durable and should last around 25-30 years with no maintenance. The only maintenance you should need to perform is to wash them clean of dirt and dust two to four times a year, which you can easily do with a garden hose."
Sounds expensive, if panels are installed on the roof. And you can't wash off pollen by just casually spraying it with a "garden hose".
HomeAdvisor quotes $100-350 a pop. As a homeowner I'd expect the actual cost to be closer to the upper end of the range. Tradesmen won't get out of bed in the morning for less than $200. To wash windows in my house from outside only is $300.
(Oops, then edited it to double that estimate)
>Your investment is recouped in 8-13 years.
So, right when you recoup your investment, the 10 year warranty runs out. Great.
You're right. 4 on this list have 25 year warranties... but the rest.. ouch.
I pay ~$50/month and that would offset most of my bill (net metering resets at year end, so I'm likely to pay most of Jan+Feb), so it should pay for itself in 10-15 years, probably closer to 10 since my numbers are very conservative (low estimate for electricity, high estimate for installation & parts, low electricity cost). Panels are under warranty for 20 years, and they immediately add value to my house, so it's a net win as soon as they are installed.
Maybe it's one of those "not my problem, it's free to me". As most people aren't thinking of themselves spending tens of thousands of dollars.
The economics of a mandate is the scariest thing. I imagine shortages of natural resources and production. It will further divide the 10% and everyone else.
Again, Solar panels do not grow on trees and their manufacturing process is chemically intensive. So, it is in the best interest of every one, that Solar PVs are deployed where they return both economic and environmental value.
Again -- here is the link to Global Solar Atlas --
https://globalsolaratlas.info/
the areas in the Red is where you want to deploy PVs. Other places not so much.
Americans aren't entitled to the cheapest new construction housing possible while foisting the consequences of that on the rest of us. No different than cars being more expensive to meet higher CAFE mileage standards. Not living in a polluted hellscape costs money, who would've thought.
Meta: Where did this entitlement complex come from that someone's pocketbook is more important than the air we breath?
If you’re worried about pollution tax the emissions, like any civilized country would. Mandating rooftop solar is way too indirect and exposes the public to corruption of the construction trades. Of course, that’s why the parties that stand to benefit from the corruption are going around the country pushing these laws.
Utility scale makes sense, but so does rooftop solar at scale (if you can streamline soft costs; permitting is unnecessarily expensive AF in the US versus someplace like Australia). A pollution tax will take time to implement, if at all tenable in American politics. Unfortunately, indirect methods are needed at times due to the political landscape. I will take a decent solution today over the perfect solution when it's too late.
I really think mandates like this are totally wrong approach. Consider that in virtually every jurisdiction in California a new home requires both solar power and a 2-car garage. If that isn’t perverse I don’t know what would be.
Unlike you I consider a carbon tax almost trivially easy to implement. Way easier and more effective than construction mandates.
Utilities can kick and scream (and attempt to subvert the mandate to maintain their relevance), but the mandate will go into force.
> Commission officials acknowledged homeowners will see smaller bill savings under SMUD’s Neighborhood SolarShares program than they would with solar panels on their roofs.
> The average single-family home in the utility’s service territory, which covers most of Sacramento County and parts of Placer and Yolo counties, can currently save around $75 a year with rooftop solar, the Energy Commission estimated. Under SMUD’s program, the average single-family home will be guaranteed electricity bill reductions of just $28 a year.
> The changes from SMUD’s initial proposal didn’t convince critics from several prominent environmental groups, including the Sierra Club and the Center for Biological Diversity. They argued the solar projects SMUD plans to use for its program are too large and generally too far from residential neighborhoods to be considered true “community” solar facilities.
https://www.latimes.com/environment/story/2020-02-20/califor...
[1] https://www.smud.org/en/Corporate/Environmental-Leadership/P...
By the way, it's not commonly acknowledged but in my experience solar panels are very underrated as effective insulators, reducing A/C costs.
Start building houses out of bricks and mortar. They will last for a century, provide shelter to your children and grandchildren and in that case, 10k for a solar system do not really make much over the time.
Second question: if the PV is part of the construction, and not bolted on afterwards, what can you save?
Third question: given that these save money and are a net economic win after a decade even when they are bolted on as an afterthought, even if the answer to #2 is “none” and even if the answer to #1 is that purchase prices go up rather than land owners can’t sell for as much, surely it’s still a win?
That being said, I'm against a mandate. Solar panels look ugly, so sometimes it's preferable to have the energy company take care of it. It also requires a decent amount of additional equipment, which means certain types of additional risk.
Instead of this type of legislation, at should just tax carbon and let individuals optimize. If fossil fuels become ~2x more expensive overnight, you can bet we'll transition to green energy much more quickly, but it doesn't push a specific solution. Maybe roof mount solar isn't the best option but some other centralised energy solution is (e.g. nuclear or wind).
Just as a single data point, my parents, who live in rural upstate NY, installed solar panels on a portion of their (connected-to-the-house) barn's roof a few years ago. Aside from times when they're literally covered in snow (which is rare, due to their temperature), they're producing power, and even in the depths of winter they produce plenty enough to offset a huge chunk of their electric bill (and in the summer, there are days and weeks at a time where they're producing more than they need).
I can't speak for the specifics of environmental impact, because I don't know the details for their panels, nor how one calculates such uneven things (how do you subtract electricity generated from the various kinds of environmental damage done to mine and refine the various rare minerals in solar panels...?), but at least economically, they're a huge win.
No, it's not. As already pointed out, Germany is full of PV, even very large systems.
Deploying solar systems everywhere is very important to decentralize energy creation (and in the future: energy storage). The future of our electrical systems lies in decentralized systems, to minimize the need for huge infrastructure to get power from A to B and also to "harden" the grids against failures.
So, it's a good idea to have solar on every house. And if it only takes care that your fridge is running on "your own" energy from the PV system that's a good start as well.
Tesla is also pioneering virtual distributed load systems, where they can have a utility send a signal similar to that used to shed AC units during high consumption periods, but the signal is instead used to command vehicles to charge when there is excess energy on the grid. [1] This would make sense today in places like Texas, that have so much wind energy (and not enough transmission capacity to other load centers) some utilities provide you electricity for free at night. Any KwH you can use instead of curtailing is a KwH of energy you're not wasting.
[1] https://electrek.co/2015/08/16/the-power-of-controllable-cha...
If a city wants more solar, then they could put up a solar farm in some rational place with a good economy of scale, and connect it to the grid.
For example, one person in a 50 m² apartment, divided by 4 floors, with 20% efficient panels, 25% duty cycle for night/latitude, still implies 625 W/person. That won’t power everything all the time, but it would reduce the required size of the external electricity source — be it PV, nuclear, fossil, whatever — by a decent amount.
This whole rooftop solar movement reminds me of 'solar roads', a snakeoil scheme a couple of years ago. It has no rational basis, and no compelling engineering support. Its just a 'roofs are flat; solar panels are flat; hey! lets put solar panels on rooftops!'
E.g. does the rooftop have an appropriate southern exposure? Is it in direct sunlight? Does it have the carrying capacity for tons of equipment? Is it a safe place to do construction? Will the roof's normal function be unaffected by solar installation?
The answer to all these things is, No.
Second, even if all the things you’ve just said “no” about are true for 100% of existing property, if this is part of the planning regulation for new buildings, then the designs can be required to be such that the answers are “yes”. I know this is technically achievable by way of having at least one example of PV on a roof.
And again, one roof for many families doesn't scale. A solar farm has every advantage over this scheme.
Do you think that isn’t obvious? So keep new apartments away from houses and vice versa. So what, no big deal.
The idea is called “planning permission” and why sewage plants are not normally next to residential areas.
Problem solved a very long time ago — which is convenient, because this is the exact same problem you’d have to deal with when planning the solar farm in the first place, because the apartments can shade solar farms too if they’re built too close.
> And again, one roof for many families doesn't scale.
Not claiming it scales with arbitrary height. It’s clearly constant with arbitrary height. Claim is that it’s still useful for ~4 stories with one family per story.
> A solar farm has every advantage over this scheme.
Except for land cost, grid capacity including connecting to the farm to the grid in the first place, and the money rooftop solar saves on the cost of the roofing material, and the way local power generation at least enables the possibility of power when the grid is down like happens sometimes in CA fire season, and the way this puts more money in the hands of normal people whereas a traditional solar farm or power plant will put it in the hand of shareholders, and the fact that large land use changes have their own ecological issues and NIMBYism (remember, if we suppose that the rooftops don’t cover enough area, then the solar farm you want to build is larger than the combined area of every building in the city it’s associated with), and the way rooftops get built every time a residential building gets built so in the case of houses it will scale perfectly with population when a PV farm or an apartment won’t. (Apart from that, what have the Romans ever done for us? Etc.)
Edit:
Just to be clear, if you were to say “American building codes make rooftop PV needlessly expensive”, I’d agree with you. My in-laws and parents both had PV installed in the UK, and even a decade ago it cost them less than half of the prices I see quoted on HN for American rooftop PV today.
However, this an entirely separate argument to the one you appear to be making.
If this sample is, by some miracle, representative; I guess it shows that Americans must live amazing middle-class lives to believe that this policy is viable.
If we want a regulation that all new construction must be powered by zero-emissions sources, say that. I'd even be in favor of it, cautiously.
But solar panels aren't a magic cure-all. They should be installed in places that make sense, which isn't guaranteed to be the roof of a new building.
In the US for instance, could we take all of the local building-codes and design blueprints that would satisfy all of the legal requirements for quality, sustainable construction, regardless of the state, city or county that you choose to build in?
Even going with a smaller scale and offering off the shelf blueprints by state may stimulate more new construction growth and sustainable designs.