The top comment from u/theysayso on the same Reddit thread seems to put things in a good perspective:
Other posters have already noted that you can still have the solar panels, you're just not going to get paid for net metering. What people typically want is the best of both worlds, to charge onto the grid when the produce more than they use (and get paid for it) and have the grid available to supply power when they generate less than they use. But maintaining the grid also costs money. If all your ratepayers split, it makes it more expensive for those "left behind". Who gets left behind? Typically people with less money, that can't afford the systems in the first place, apartment dwellers, etc. The other noted challenge are battery systems. You can go completely off the grid but installing the batteries is WAY more expensive, takes and takes up a lot of space. The technology is disruptive, which the article really didn't go in to. For PV to push electrons onto the grid it needs to be at a greater potential. So if your local grid is 120v the PV needs to adjust to 120.1v. Then your neighbor installs one, and this her/his neighbor. If you're on a long radial line the voltage at the head end might be 126 just to get it to be 118 at the tail end. Normally a utility will install capacitor banks to adjust the voltage. Now you have PV going in everywhere totally screwing with the voltage so it becomes a bit of a grid management challenge. You need to know where all that is going in, what its rate of power is at any given moment (clouds/rains suddenly everything changes and the utility has to compensate). So yeah, a sticky problem that could get out of hand pretty quickly.
Here's a redneck way to build something like that:
1) Get a beefy inverter and a beefy battery - the inverter should be rated at 150% of your load, and the battery should be whatever car battery happens to be on sale.
2) Get a beefy car battery charger. It has to be able to handle 150% of your load as well.
3) You now have a UPS that doesn't discriminate where its power comes from.
4) Get some beefy diodes, as beefy as possible. You'll need quite a few, so buy a 25-pack on digikey.
5) Hook up your solar panels so that they give you 12 volts nominal. Then, use 21 of the diodes to create a shunt that triggers at 14.7 volts (just connect them in series). That is your overcharge protection.
6) Use four more of the diodes to connect the battery charger and solar panel to the battery, in such a way that each power source does not "see" the other (common ground, two diodes in parallel from panel+ to battery+, two diodes in parallel from charger+ to battery+)
7) For the love of God, ground this thing (battery-, charger- and panels- to a metal pipe or a ground connector in a socket).
You now have a complete, if small, setup for only calling upon the power grid when your solar panels aren't cutting it.
This system can be dismantled into its components quickly, which is nice if you need to charge a battery or need an inverter.
Unless subsidised its a long way before home PV makes sense. if I notice PV at the larger or more convenient locations for it in my area (the pool, the storage warehouse, the substation, apartment blocks) I might start to consider whether viable as a cost effective single-house solution.
I know that in New England, where I'm from, it's only major state govt subsidies that make home PV economically viable. Even then, it takes 15-20 years to break even.
As someone that lives in Mass (which is in New England) and purchased them in 2011 See http://benjamin-meyer-home.blogspot.com/2011/08/solar-panel-... looking at my data i'll be breaking even in about 3 more years (about what I planned which was 4-5 years). And this takes into account the fact that SRECs are worth a bunch less than when I started.
In Hawaii, PV was subsidized for a long time. Unfortunately they've cut those back earlier this year. (Around January 2013)
Since electricity is so expensive[1] here many people could reclaim their investments in as little as 5 years. With the subsidies reduced, it may be 7 years. That's incredibly short if you compared Hawaii to the mainland.
An awful lot of PV break-even analyses assume the cost of grid electricity will remain constant. Hawaii's electricity is oil-generated, and I suspect oil prices will continue to rise rapidly in the next decade.
It's still rising faster than inflation, and on an island like Hawaii fuel oil is more expensive due to the shipping costs. Kind of surprised they don't use geothermal preferentially to solar, but I suppose that unlike Iceland they have a better mix of solar resources available there.
Geothermal was debated back in the late 80's but was protested against as source of heat (lava) is a god (Pele) in Native Hawaiian culture. It is especially controversial since the proposed geothermal site was on Native Hawaiian homelands.
If I remember correctly, the group didn't want any money from the proposal. They just didn't want the drilling to be done at all. The group battling the geothermal proposals believed that the drilling would damage their god and absorbing the heat to make energy was absorbing the life force of their god. I don't know this subject very well, so if you want more information you should look up what the Pele Defense Fund has done.
I know that as enlightened individuals we're supposed to respect all creeds, beliefs, and faiths, but frankly, I doubt there is anything that anyone can say to me that will make me respect the people who have (apparently successfully) blocked alternative energy production efforts because it will drain the power of their lava god. If it's true that I share more DNA with these people than I do with a chimpanzee, it's strictly a fluke of evolution.
(Edit: To be fair, some Googling suggests there are some more tangible environmental concerns with geothermal energy in Hawaii, but propitiating Pele appears to be a very real part of their argument as well. If we laugh at and ignore their legitimate concerns because of the 'Pele' argument, that's just as unfortunate an outcome as one in which religious nutters stop a worthwhile project in its tracks.)
The native Hawaiians were only on Hawaii for what 800-1400 years before Cook got there? This has more to do with Hawaiian sovereignty from white dudes than religious beliefs.
I have been to Hawaii and many natives would rather bite their own hand off than touch a haole.
The bet that oil prices will increase as supplies diminish discounts the feedback on demand.
Oil is useful because it can be used to produce value. That value production starts at the margin, and there's a lot more you can do with $10/bbl oil than you can with $100/bbl oil, and more with that than $1000/bbl oil (and in case you question that, it's about the production cost per barrel of canola-oil derived biodiesel). Which is to say: oil prices might not simply increase with scarcity.
But price drives what sources are feasible for extraction. Early oil didn't cost much to extract, and its price was low. As oil's become harder to find and pull from the ground, its extraction costs (and minimum market price) in crease. Much of the extraction at the margin is only feasible because of high oil prices.
Ultimately you may reach a level at which the global economy is caught between oil that's too expensive to buy, and a market price that's too low to support exploration, development, and extraction.
Gail Tverberg's explored this dynamic in some detail:
Only about 60% of the cost of installation of a solar system nowadays is the cost of the PVs themselves. You still need racks, mounts, wiring, inverters, etc.
First of all "keep going down" ? Good, but they're, well, not there yet. I don't think it's possible for residential solar to become actually profitable given that we already have an electricity grid, without causin the consequences illustrated below. For now lots of things are still under subsidy, and this masks the problem.
Second solar has the problem that it creates a tragedy of the commons. This has been obvious in several European markets now. Once built, the electricity is free, but not continuous. That means that for the majority of the time, traditional utilities have no hope whatsoever of competing with solar prices ... and then comes the 10% not covered by solar or wind (it's easily more than 20%, but I get a feeling we'd get into an argument).
At that point electricity is needed from traditional sources. Of course, because of this they need to be ready at a moment's notice. Capacity needs at that point might vary from 10% of total to 100% of total, so you still need the same fossil fuel capacity you have right now. It doesn't have to run at full speed anymore, of course. It can't be turned off, because when renewables fail, they don't give you much warning (we're talking minutes at most).
Note that means that large scale renewable plants cannot be used to power homes, because of economics. The more of this you have, the less efficient the market becomes (because the smaller ones maintained "for free" by individuals can't be beaten on price).
It has other pros and cons. In the case of plant failure, the system is much more resilient. And in the case that something disables most small plants (say, an earthquake), the system is much more affected than today (because rooftop solar just isn't built to power plant standards). Double this effect for comparison against nuclear (which is built to withstand ridiculous stress for obvious reasons, and that means it can almost always simply remain operational during a disaster)
Here's the kicker :
Disconnecting from the grid is not realistic for most people, Chung said. The current state of battery technology means they have to be replaced after a few years, he said. And putting a system with batteries on a typical house would cost $40,000 versus $25,000 for one without the storage component, he said. Moreover, the battery portion isn't eligible for the tax credits.
(this isn't entirely true, it's only true if you "minimize" the storage component. A battery that can hold 3-5x the power that will ever be drawn from it will last 20-30 years -at least- under that load. If you load it up > 95%, you get 2 years at best)
So we're stuck upgrading the grid ... Or making solar installations 2x or 3x more expensive than the currently are, and not just in money : you need battery chargers, space (batteries aren't small), maintenance, ...
So there's 2 things we "can" do:
1) do what greens suggest, and make the rates reflect the new cost structure. Of course that means effectively raising the rates on traditional electricity by a factor of 10 or 100. This will mean that anyone who doesn't have solar right before this happens is so thoroughly screwed it's not funny.
It will also disproportionately affect the poor. For two reasons. First, they can't pay for their own little renewable plant, and can't get the loan. Second they usually live in highrises that cannot be powered using renewables, except for the penthouse. If you think this is wrong, call up a picture of residential highrises in Hong Kong, you'll see what I mean.
It will also reduce the size of the economy. Energy is one of those non-negotiable things, with almost zero price elasticity. It's effectively a tax. Even more so because the government usually controls the other side.
Oh and, in toto (everything taken together), it's less efficient than centralized production. It's attractiveness (to no...
I agree with most of this but there is option 3. Solar people buy batteries and don't return power to the grid. This is probably a bad outcome for the average electricity user as well since the richest, most heavy users, won't be participating. My guess is the end game is a "grid connection fee" with a tax credit.
I like option 3. Why is it a bad outcome for the average electricity user? As the demand on the grid reduces the prices should fall down for those using the grid. In the very least, they shouldn't be affected.
As the population on the grid falls, the infrastructure cost per head increases and the cost of borrowing for infrastructure upgrades also goes up, because a company that is losing customers is a risky bet for the bank.
"Disconnecting from the grid is not realistic for most people, Chung said. The current state of battery technology means they have to be replaced after a few years, he said. And putting a system with batteries on a typical house would cost $40,000 versus $25,000 for one without the storage component, he said. Moreover, the battery portion isn't eligible for the tax credits."
So population on the grid does not fall. What mostly falls is the revenue from them. 90% of the time they're not paying (or even paying negative amounts thanks to the laws the greens forced through). The company can't disconnect them, and if the greens have anything to say about it, can't charge them. They need to provide backup power though, because the solar installations can't do that (without tripling in cost).
It does in the point I was actually answering to though.
I was answering the question; "I like option 3. Why is it a bad outcome for the average electricity user?", where option 3 is "Solar people buy batteries and don't return power to the grid."
You are basically saying you think there is a low likelyhood of the topic of the question someone else asked becoming reality. But I didn't propose how likely it was one way or another, I was just answering the question that they asked about the downsides.
because the electricity company will still need the full capacity of the grid in power plants spinning idle to be able to react to renewble output changes. So not much savings on existing infrastructure.
That combines with selling 50-60% less in the limited deployment case, 90-95% less.
That means prices will need to increase by a factor 3 in the limited deployment case, factor 10-20 in the green's "dream scenario" case.
when renewables fail, they don't give you much warning (we're talking minutes at most)
If your country has a lot of hydro (which has ramp times measured in seconds) this doesn't matter.
Additionally, clouds don't magically appear and obscure an entire cities sunlight over the course of a few minutes. They pass over cities, so as one area loses solar generation another is regaining it. Or maybe it's an overcast day where the the solar generation is at a predictable low level all day. Neither of those cases pose any problem to hydro or any other plant that can ramp up and down over the course of a few minutes (and every nation has these - you can't run a grid without low-response time generators)
In the case of plant failure, the system is much more resilient. And in the case that something disables most small plants (say, an earthquake), the system is much more affected than today (because rooftop solar just isn't built to power plant standards)
I'm not really sure what you're saying here. That distributed generation gives you resiliency? In Australia and NZ, if the grid goes down then your solar inverters turn off too so it doesn't affect the grid's reliability at all. I believe most countries have this requirement.
How does not being "built to power plant standards" have any effect? Your inverters are still required to generate clean AC, and if they can't match the grid closely for any reason they stop generating.
"In Australia and NZ, if the grid goes down then your solar inverters turn off"
Yes... and that's precisely the issues here. How do you know when the grid is down? You'd see a drop across your grid connection? Makes sense. But what if the grid went down, but because all the local houses were supplying greater than 100% of the local load requirements, it never looked like the grid was down?
That's the challenge. As I understand it, power utilities are considering "smart grid" as a distributed control mechanism to kill PV interconnects in such instances. However traditional grid control is normally built very stringently to allow fast detection of issues and fast isolation/resolution with redudant lines. If you have one rogue smart control point, you could end up electrocuting the engineer.
If the grid supply goes down for some reason (natural disaster, car hits transformer, significant sustained overload blows pole fuse etc) then everything connected to the grid in that area will see some or all of the following effects:
* sudden change in supply voltage
* sudden change in frequency (and rate-of-change of frequency)
* sudden change in phase angle
You can't mask these signals and they are particularly pronounced on the section of grid that was affected (i.e. the part that is now blacked out). These (and more) are the specific effects that inverters monitor for, and they will disconnect if they notice anything unusual. Inverters aren't checking for the presence of a grid supply, they're monitoring it's health. Your local lines company dictates the trip limits based on your address and size/type of installation.
As for safety, compare some scenarios that a lines worker could actually find himself in:
1) he has turned up to a fault and found that a HV line is on the ground and the auto-recloser is still trying to re-liven it at periodic intervals. The voltages are so high that walking anywhere near the fault could result in him being electrocuted due to a step voltage. The power levels involved are high enough to cause a major explosion.
2) he has to open or close a circuit breaker in a switch yard. He has no way to know whether the breaker is going to explode when he racks it in. At least he probably won't know about it if it does blow up.
3) he turns up to a fault on a 230V line, tests it and finds that there's still voltage present despite the earlier fault. He visits the houses connected to that part of the circuit who have a grid tied inverter and manually isolates them before investigating further.
That last one is hypothetical, since I've never heard of an inverter failing to turn off and even if one did stay on initially it would very quickly trip on overload after trying to supply your house and your neighbors all by itself.
Testing the safety of a circuit before you work on it is an everyday part of the job for electricians. Finding that a circuit is still live is very common, and having one re-liven unexpectedly happens too from time to time. You just take precautions, wear protective gear, and do your best to minimize the danger.
The grid is profitable enough for the power comanies to invest in storage tech like this - http://www.gravitypower.net/ - or this - http://www.lightsail.com/ - which provide the grid response of hydro, but with the flexibility of being able to put it in at the local level. Now as to the question of centalised being more efficient, it is not at all clear, given transmission losses, if that is true with solar systems that have local storage.
As I noted in another comment, peaker plants are in trouble everywhere. I don't think we'll see a political compromise soon enough, and expect a utility death spiral.
We're already at grid parity for solar on a kWh basis in places like Hawaii. What's more, solar supply matches A/C demand. Reducing and shifting most of the demand with home automation will cost less than buying batteries. Some people will just disconnect from the grid, maybe even connecting with their neighbours.
The maintenance costs for the grid won't go down as fast as people dropping out, so retail prices have to go up -- engendering a positive feedback loop.
As far as energy being non-negotiable with zero price elasticity: this is true in the short-term. We've seen the same thing with cars - eventually people switch away from gas guzzlers. More efficient appliances and architectures take a long time to show their effect, yet they have just as real an impact on total demand.
It's hard to argue that inefficiency is good for the economy. In fact, proponents of alternative macroeconomic metrics cite the GDP's bias against efficient renewable energy as one of its flaws [1].
If you pursue a bigger economy without considering efficiency and the societal benefits of other labor/capital allocations, you run the risk of prescribing bad policies. E.g., a government can grow GDP just by hiring idle workers to dig ditches one day and fill them back in the next.
[1] de Graaf and Batker. What's the Economy For, Anyway?
Distributed power generation can never match the efficiency of centralized, for obvious reasons.
This may not matter for renewables, as there's no fuel burned ... but ... I doubt it will turn out that way. So a larger cost will be much more efficiently distributed amongst it's users.
By efficient I meant it achieves the same result with less cost, not that it minimizes electricity waste. If distributed solar "will also reduce the size of the economy", doesn't that mean it's more efficient?
>if I notice PV at the larger or more convenient locations for it in my area
You might not notice them. Last time I took a plane, when landing I was surprised at the installations I didn't realise were there. Large rooftop installations are common on stores such as Walmart, Ikea and others.
The time is already here. Anyone can now buy panels at ~$0.50 per watt, from Alibaba. To power a 10,000 watt home costs ~$5,000 in panels. Add $1,000 for an inverter and misc, add another $4,000 for installation labor (I'd pay ~$1,000), so for $6,000 to~$10,000 in total costs one eliminate their electric bill. That's a payback of ~3 to ~4 years. A 3x to ~4x revenue multiple seems like a cheap price to pay for an income producing/saving asset.
The capacity factor for most of the U.S. is a lot lower than 1. If you actually have 10,000 watts of demand, you need more like 40,000 watts of panels.
(Lots and lots of homes would probably meet most of their usage with less than 10,000 watts of panels, but they also aren't paying $3,000 a year in electric bills)
>Other posters have already noted that you can still have the solar panels, you're just not going to get paid for net metering. What people typically want is the best of both worlds, to charge onto the grid when the produce more than they use (and get paid for it) and have the grid available to supply power when they generate less than they use.
This ought to be the best of both worlds for the electric grid, too, since solar generates electricity when load is at its highest.
However, the grid is not concerned with running efficiently, or with minimizing environmental damage. They're concerned about their net profit.
Profits on day-generated electricity are much higher than profits on night generated.
>This ought to be the best of both worlds for the electric grid, too, since solar generates electricity when load is at its highest.
Unfortunately, not.
Demand peaks early morning and early evening, when solar is near its minimum.
And in winter, solar is near zero at those times.
So solar net metering has always been a bad deal for the utilities when you take into consideration the fixed costs they have for maintaining the necessary reserve to cover peak usage.
Note that Hawaii is (mostly) below the Tropic of Cancer, so gets quite a lot of solar radiation even in the winter, and the length of a day only varies by a couple hours throughout the year ([1], [2]). I don't know the math offhand, but even without adjusting the panels, I'd expect that the winter output is probably pretty significant.
We tend to think of Hawaii as sunny and warm all the time, but it's actually just an "above average" place for solar generation. Honolulu gets about 90 sunny days and 181 partially-cloudy days.[1] Phoenix on the other hand gets 211 sunny days and 85 partially-sunny days.[2]
It's not just about sunrise and sunset, but UV index and cloud cover. Here's some actual data on actual solar generation:
This shows that even on the sunnier Oahu and Maui, solar generation is more like Nebraska than California.
The fact is that sunny days drop about 30% in the winter and UV index is down.[3] I wasn't able to find real-world MWH in Hawaii per month, but I'm guessing it's about a 50% drop overall with some days actually at ~0. Certainly not 0 for the month, but the fact remains that you need backup power for low-solar periods with more capacity if you want to leverage excess power in high-solar periods.
What you say is probably true in Michigan, but not so much in Hawaii. For big parts of the US, AC stands for most of the consumption, and you do have the highest power demand when the sun is strongest.
Just to muddy the waters further, most people are at work when the sun is strongest leading some to recommend that home PV arrays should be orientated towards the evening sun. Of course if your home and work electricity grid is connected then this could be mitigated.
That is actually incorrect for the majority of places. Industrial and business related consumption tends to dwarf home owner consumption, and is usually at its peak during the day.
That's not really an accurate picture of net metering.
The terms of almost every net metering plan are in the power company's favor, even if the net meterers somehow never bought power.
Net metering, as currently implemented, only allows you to earn credits on your bill up to the point where your maintenance fee kicks in. You're earning credits by producing power for the company during the day, when power is expensive. You're burning those credits to keep the lights on at night, when the company's cost of power is nonexistent. No one is paying net meterers market rate for time of day, so the power companies are coming out way ahead on cost of power. Even if that weren't the case, they still baseline your bill to a maintenance fee.[1]
Moreover, Hawaii has never had any clue how to balance a grid, so if HECO is now blaming customers for problems with the terrible system they built, my default position is skepticism.
I'm really pulling for a neighborhood microgrid movement in areas with abundant solar, terrible power monopolies, where a bank of vanadium batteries is overkill for one house.
Don't get me wrong. Only some power companies are awful monopolies that barely do their job, most work fine. Still, those awful monopolies should face some threat of revolt.
> I'm really pulling for a neighborhood microgrid movement in areas with abundant solar
This is a nice scheme around and between the tropics, and just about nowhere else. Because you need not just abundant sun, but abundant sun year round.
Germany's already getting a lot out of the source with terrible insolation.
Temperate areas would need to lean on storage more. As generation efficiency increases, storage losses matter less. As storage technologies improve, poor insolation matters less.
But sure, someone invents a nice kitchen-sized baseline reactor that anyone can run, then this microgrid movement really takes off. Probably not in the next couple weeks. ;)
Utility reliability requirements are set by PUCs and Federal Regulators. Unless the neighborhood microgrid is always islanded from the grid, there are quite a few problems to solve:
1) Who will respond to outages and make repairs. This includes issuing clearances to crews making repairs.
2) Who will issue protection settings (reclosers/relay settingsfuse coordination, etc) and perform fault analysis?
3) Unless you have generators then they'll need to provide power when your PV systems don't meet demand
4) Someone needs to investigate power quality problems
5) Generation dispatch to meet demand and maintain a system frequency of 60Hz.
6) Someone must handle interconnection requests. Who is going to stop your neighbor with a 50Hz generator that can handle 50% of your microgrid load from connecting to the system, causing a big frequency drop and damaging appliances? Your microgrid doesn't have enough inertia to absorb something something like that.
7) Are the micro grid operators subject to the same reliability requirements as utilities?
8) Are you going to install your own poles and wires? That includes permitting, responding to joint use requests per regulatory requirements, etc.
Some of these issues are created by the bulk power system model. For example, heavy industry and long distance transmission require much more precise balancing than neighborhoods. Others can be financed in the same way that HOAs finance capital improvements, or the same way tenants of an apartment benefit from the use of a building and maintenance crew they could never afford to build or have on retainer individually. Others would be obvious how to resolve in practice (ie, How do you prevent your neighbor from wrecking the system? Well, how do you currently prevent your neighbor from hooking up his pipes to the neighborhood fire hydrant? A combination of common sense regulations and social mores.)
If our default position were microgrids, we might wonder of a unified system, "but how would you prevent cascading blackouts?" The current answer is you don't, major cascades just happen around once a decade.
It's all a series of tradeoffs, and I agree with you, usually the tradeoffs favor bulk generation. The balance shifts when monopolies abuse the public trust. So here, things like load balancing are an interesting example, since that's not an area where HECO has always excelled. UCSD is using a microgrid because they can't achieve sufficient reliability from California's bulk power system:
Capacitors are typically used for power factor and voltage correction. A minor correction on what theysayso wrote. If the line is long enough, voltage regulators are used to increase the voltage at a certain point.
Phasing for lines is checked by a rotation meter, it is either A-B-C or A-C-B. Get it wrong and your motors spin backwards.
I think ultimately this will cause people to install these systems to run non-essentials, with automatic switchovers, and optional battery backup fed by solar. And yeah, the switchovers and batteries will be expensive, but once utilities start doing this en masse people who want this bad enough will suck it up and get their personal benefit from using "free" electricity and possibly doing the planet good, rather than from selling electricity back.
They mention one person's cost for a PV system with batteries in the article, it was $14,800. (Look for "Hayashi bought a system with batteries"). It also states the buyer will be able to recoup his upfront cost in 2 years thanks to tax credits.
There is no technical mystery here. We just need the right legislation to awake utilities from their century-long sleep on infrastructure investment. Americas grid is an embarrassment.
I don't know about net metering, but you can build a serviceable system with 12 volt PV cells, recovered UPSs, and some lead-gel batteries (which you should store outside). You can use car alternator diodes for overvoltage protection. Should I draw a schematic?
Hawaii has the highest cost of electric in the nation. I used to live in Hawaii, and working from home, my monthly electric bill was $500-$750. Hawaii also has year-round sun, being close to the equator. The state also has rebate programs for solar panels. When I was looking into it, if you got a 5-year loan, it would be cheaper to buy the panels than pay your electric bill.
There's no (legitimate) reason Hawaii's electric should be so high. They just have no incentive to reduce prices, and they have to keep their 6-figure salaries. I knew plenty of people that wanted to build solar/wind farms, but the electric company either wouldn't accept their electric at all, or would give them pennies on the dollar.
Did you consider options like swamp coolers? I'm not familiar with Hawaii's climate so I don't know if they would be effective, but that power bill is more than many people pay in rent...
I never heard of swamp coolers before. Honestly I think the problem was I just kept my mainland lifestyle. In Hawaii, people keep electric consumption in mind with every purchase. Most people use fans instead of A/C. High efficiency appliances. Even keeping lights off whenever possible. I didn't realize the electric problem until after I had already purchased the large screen plasma TV, A/C, etc.
Swamp coolers are basically just water mist things connected to big fans. They work off of evaporative cooling, so they are extremely effective if it is dry but not effective at all if it is humid.
I know on Oahu, certain parts of the island are very dry while others are extremely wet. I haven't seen evaporative coolers on this island. They might be here, I just haven't heard of anyone using or talking about them. Many people have older homes with jalousie windows and rely on the trade winds to cool their homes down.
Hawaii is humid (surrounded by water, right?) so swamp coolers are out.
For the prices, if you'd ever been to HI you wouldn't be surprised. Everything costs more there, a lot more. Again, it's several thousand miles from the nearest major landmass
How do we reconcile the fact that base-load generation (e.g. coal, nuclear) is hard to throttle, yet PV is increasingly sapping the profits from peak generation hours (i.e. mid-day) resulting in economic disruptions and perhaps ultimately in off-peak electricity disruptions as base-load generators become increasingly expensive to operate?
I personally think that that's the reason the brakes are being put on PV, and not the populist "robber baron" explanation offered by the article.
If the grid operator is primarily concerned with profits from peak generation hours, and trying to prevent solar from impinging upon that, it doesn't seem reasonable to legislate a way to protect those profits, ESPECIALLY not when it is environmentally damaging to do so.
The rate schedules are highly regulated. If they lose the peaks they are going to either get an increase in other rates or throw their hands in the air and turn it all off.
The second would be a huge problem. The first is something lots of people are going to complain loudly about.
Sure. But lots of those people are currently staying away from solar because of the capital costs.
It sort of seems like the two big inflection points will be solar getting so cheap that it pays for itself in a few summers and neighborhood or household scale batteries becoming practical.
There is always the even more expensive choice of going off grid entirely. But that requires a power storage facility of some form.
If we are fortunate and can get to reasonable "supercap" sort of technology this will become easier.
I note with some interest though that most roof top systems put only enough out that they could, in theory run a Tesla Super Charger to a Tesla battery supply. You could then pick a point in the afternoon where you did the 'switch' and switched over to inverters running off the Tesla battery pack. Providing electrical load from that point until it got below a set charge point on the batteries. Some days you'd probably go from 4PM to 9 or 10PM, others only until 6 or 7. But you would get the benefit of not having to pay for that power when you were running off the Tesla. Elon if you're reading this you should figure out how to make that happen, you'd get better volumes on the batteries with Tesla (better economics of scale) and people could do this without utility participation.
Is the battery technology the same? I'd imagine in cars space is at a higher premium and may have other constraints that seem like they might perhaps be less-than-optimal for houses. I recall seeing large banks of lead-acid(?) batteries in datacenters and at a few houses.
With a super capacitor charge is stored as charge, and in a battery charge is stored by a reversible chemical reaction. The challenge of running the chemistry back and forth in a battery is what causes them to wear out eventually, and limits charge and discharge rates.
When we put solar on our house we looked at putting in a whole house "ups" as it were (the typical off grid setup was not unlike a data center, batteries that carried you until you could get on to generator power) The maintenance and replacement of those batteries is a pain.
But in terms of kWh stored and power delivery ability, the packs we were sizing were not unlike that of a Tesla Model S (65 - 75kWh) and Tesla has already got a replacement and refurbishment plan in place, and the packs themselves need no maintenance under normal use. So it seems like an interesting pre-packaged solution, except you'd need a high efficiency house inverter as well but progress there has come from the solar investments.
Lithium batteries are interesting because they store 200Wh/kg, vs. 40Wh/kg for lead. But they're dramatically more expensive, about 500€/kWh vs. about 100kWh/kg for lead (difficult to compare precisely, due to different tolerances to deep discharge among others)
One of the big problems with PV and wind power is that they don't offer any inertial load on the grid. This means that once the percentage of these sources increase the grid frequency stability decreases.
When using renewables you must still generate a majority of your supply from a big rotating generator. The inertia of the spinning generator keeps the frequency from straying from 50/60hz.
In Ireland they broke a record a few years back for having 50% of the electric generation coming from wind power. This was at the upper limit set by the grid operator (eirgrid) because above this level the frequency of the grid becomes unstable. Even though more wind power was available they didn't add it to the grid.
Poor, poor, Ireland. That must be just awful for them. Thank God we in America aren't at risk of hitting that 50% figure of energy supplied by wind or solar.
System Non-Synchronous penetration (SNSP) is a real-time measure of the percentage of generation that comes from non-synchronous sources, such as wind and HDVC interconnector imports relative to the
system demand. In the Irish grid this is limited to 50% for stability.
I think the US uses 10% spinning reserve for generation (might be a NERC requirement?). Some plants (gas and certain hydro) have fast response times. Others (coal, nuke?) have a longer response time.
The biggest issue with wind is that the wind gusts so power output is variable.
As regards to frequency until your system has enough mass to influence the rest of the grid, the grid frequency is dominate. Even a 2,000 MW generation facility will not influence the grid frequency much, which is why it is important to sync to the grid as you connect.
Just an anecdote, but I had a conversation with a statistician who worked for the electric utilities here in Australia, and he said that solar subsidies had been so successful that it has caused a large and completely unanticipated net drop in power consumption over the summer months. Further, the situation is embarrassing for the authorities because they negotiated massive electricity price rises on the basis of needing large infrastructure improvements to handle future load. These price rises have been very politically sensitive as they are asserted to be part of the cost of the "carbon tax". It is now clear there's no need for even a fraction of the infrastructure they're building, and one consequence has been that there's been a rapid scaling back of solar subsidies to try and make all parties look a bit less foolish.
I think the moral of the story is that people are way more enthusiastic about installing this kind of thing than rational analysis would estimate.
Wait a minute. Increased decentralization of power generation _does_ make large network improvements neccessary. This does (in the case of Australia) not have anything to do with load, but with locality and network resilience.
The traditional electricity network is a bunch of interconnected star-shaped networks, each with a large power station in the middle. You now not only have to get bigger power lines to where the decentralized "power stations" are, but you also have to increase the overall interconnectedness, to avoid instability (think parts of the network going out of phase with other parts, localized overload and so on) due to the volatility of the renewables.
Unlike Australia, some countries with unevenly distributed renewables do indeed also have to massively increase their overland capacity (central Europe).
Yes and no. As I understand it -- most of the network improvements are to do with Peak Load. (ie -- the days where it's 45 degrees C and every household is cranking A/C). Solar PV definately helps reduce those few days a year Peaks.
In the Australian context -- as I understand it -- the Privatization of the Electricity Generators was such that they are legislated to only charge a fixed % of their costs. So the only way for them to make more money is to increase their cost-base (aka "Gold Plating") and then charge their customers the additional fees.
>> Unlike Australia, some countries with unevenly distributed renewables do indeed also have to massively increase their overland capacity (central Europe).
Only in neighborhood circuits where residential PV is significant. Utilities don't want to. Government should force them.
Unless the energy companies get to make a profit on solar power they will fight it tooth and nail with lobbying and legislation, no matter how good it is for the environment.
Why not set up a system where energy companies install and maintain solar panels on peoples' houses and then charge for the maintenance as a service (as opposed to individuals paying for their own panels in order to reduce their power bills)? That way they will be incentivized to not only offer solar power, but to invest in technology to also make it more efficient. Also individual home owners will not need to outlay such a large initial cost.
I'm a little late to this game but I've heard similar stories years before (maybe California and Germany?)
Does anyone know if utilities are changing their installation design books? To me that would be the first place to start. I don't know about Hawaii but I know in other parts of the US massive subdivisions are being put in on a regular basis. I would hope that those new subdivisions would be geared to support this use case.
I've just had panels installed (in the UK)[0] and we use a hot-water converter [1].
If we're generating 2kW, and only using 600W - the excess of 400W is not fed back into the grid; it goes into an immersion heater and gives us hot water.
That saves us on burning natural gas, and prevents problems with the grid.
Now, depending on where you live, hot water may not be the most pressing problem. But it's slightly more practical that spinning up a fly-wheel :-)
Typical transmission design is a loop for redundancy. Distribution lines will have loops, for the feeders, with an open point such that it is actually a radial system but one that can be fed from 2 substations/circuits. Laterals are the lines where there are no redundant circuits. The other option is networks, which are much more expensive but have much more redundancy.
Lateral design: typically a load curve is used to calculate the maximum load for each service point. The system is typically designed to handle close to that amount. If a house has a 200 A main breaker then it can use up to 160 A of current (unless the NEC changed since I did this type of work). Typically a house will never use 160 A even at peak load, but better safe than sorry so a 37.5 kVA transformer is probably used.
The power is designed to flow from upstream (substation) to downstream (point of service). The system protection (reclosers, fuses, circuit breakers, etc.) are designed to interrupt over-current from the downstream headed upstream. The exception to this is a network design where protection is designed to protect equipment in both directions. Network design does not happen much at the distribution level, although it is used in major cities.
If customer(s) are(is) adding power to the system then at a certain point you will have reverse power flow. And if the system is not designed for this, then bad things could happen and customers are not happy when the electric company causes damages. So the utilities want to be careful.
If the rate payers (customers) want a reliable system with the ability to feed power back onto the system then there will be a cost associated with it.
For the most part utilities have a monopoly granted by the state and are good at lobbying to protect their interests. What is best for the customer might not be best for the utility.
My ConEd bill is broken up into delivery and generation charges. I think it is fair for you to be able to sell power back to the grid, but either at the whole sale generation cost; or alternatively the generation cost less the delivery cost. Allowing you to sell it wholesale like any other power producer seems like it could be a reasonable compromise. That amount might fluctuate too much to be something understandable or usable. If the distribution cost is deducted from the amount you net meter, that would also compensate the utility for having to build the infrastructure to handle the reverse power flow. This second alternative, of course, has the disadvantage that the power is "delivered" twice (and thus charged twice).
Today, there's another thread on the front page [1] related to the Google Fiber "no servers" clause.
So, be it information or energy I can't help but notice the similarities there. Our networks were essentially designed, decades ago, for mass production and consumption, I have no doubt we'll end with more distributed energy production and storage means similar to what happens with the rise of fast, symmetric Internet connections but in the meantime we'll see a lot of these stories while the evolution finds its way.
Regarding the electricity consumption, we have access to the French realtime data online [2], I don't know if there's the equivalent in the U.S., I'll be curious to see the data for Hawaii. It's interesting to note how the daily consumption patterns differs between summer and winter (we have a lot of electric heating in the winter and little, albeit increasing, AC in the summer). Obviously there's a limit to how much PV you can plug on the grid without proper storage but it doesn't seem that's already a problem.
I saw a whole house natural gas electrical generator at Costco for only $2000 I think.
If the grid wont take you I wonder if someone could use solar panels during the day and use the generator at night. Wouldn't that be cheaper than batteries?
What is completely unnecessary is connecting your solar power equipment to HECO's systems.
Buy some good deep cycle batteries and store your own power off grid.
I live in an area which HECO has chosen not to serve, so that solar is a no brainer.
$0.49 per Kilowatt Hour is what HELCO (Hawaii Electric Light Company, HECO's Hawai'i County subsidiary) charges, which is the highest price for electricity in the USA.
I certainly don't need a $35,000 solar power system, I'm getting by on a system which cost me about $5k.
My basic needs are refrigeration and lights, as well as power for small electronics.
For high draw appliances I use a gasoline powered generator. (washer, propane dryer, power tools, etc)
It must be nice to have the option of solar panels, at present I have a metre of snow on my roof and that's on the south side.
And that's after I spent three hours shovelling off as much as I could before the ice storm hit us today.
It snow 15cm before the ice storm now I'm back to square one.
I'd like to have solar panels but I can't see how I could keep them from being covered in snow without shovelling them off off at least once per week Dec to Feb.
Couldn't you just wire up resistance heater wire between the panels? It might take a little while to melt all of them but that would be a pretty simple solution.
What is the power utilities number one priority? Profit? Supplying power? Providing reliable power? Serving its customers? Buying back power from PV arrays?
If you answered any of these, you're wrong. The number one priority (at least in the utility I contracted at) was safety. Safety was front and centre in almost all design decisions related to power system control, and was the dominant company culture. Even "low" voltage distribution of 230v is dangerous without the correct equipment and training.
Let's put aside the issues with local transformers and substations - at the end of the day, AC power are relatively straightforward systems (though they are far from simple). The control of those systems is, actually, quite complex, and deals with multiple failure states. Adding PV supply into the mix is problematic. Though well studied, it appears that without better electical signalling (for example, overlaid at the local sub/transformer), Islanding will continue to be an issue.
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[ 44.7 ms ] story [ 447 ms ] threadOther posters have already noted that you can still have the solar panels, you're just not going to get paid for net metering. What people typically want is the best of both worlds, to charge onto the grid when the produce more than they use (and get paid for it) and have the grid available to supply power when they generate less than they use. But maintaining the grid also costs money. If all your ratepayers split, it makes it more expensive for those "left behind". Who gets left behind? Typically people with less money, that can't afford the systems in the first place, apartment dwellers, etc. The other noted challenge are battery systems. You can go completely off the grid but installing the batteries is WAY more expensive, takes and takes up a lot of space. The technology is disruptive, which the article really didn't go in to. For PV to push electrons onto the grid it needs to be at a greater potential. So if your local grid is 120v the PV needs to adjust to 120.1v. Then your neighbor installs one, and this her/his neighbor. If you're on a long radial line the voltage at the head end might be 126 just to get it to be 118 at the tail end. Normally a utility will install capacitor banks to adjust the voltage. Now you have PV going in everywhere totally screwing with the voltage so it becomes a bit of a grid management challenge. You need to know where all that is going in, what its rate of power is at any given moment (clouds/rains suddenly everything changes and the utility has to compensate). So yeah, a sticky problem that could get out of hand pretty quickly.
http://www.reddit.com/r/technology/comments/1tey5l/a_solar_b...
credit: http://www.reddit.com/user/theysayso
1) Get a beefy inverter and a beefy battery - the inverter should be rated at 150% of your load, and the battery should be whatever car battery happens to be on sale.
2) Get a beefy car battery charger. It has to be able to handle 150% of your load as well.
3) You now have a UPS that doesn't discriminate where its power comes from.
4) Get some beefy diodes, as beefy as possible. You'll need quite a few, so buy a 25-pack on digikey.
5) Hook up your solar panels so that they give you 12 volts nominal. Then, use 21 of the diodes to create a shunt that triggers at 14.7 volts (just connect them in series). That is your overcharge protection.
6) Use four more of the diodes to connect the battery charger and solar panel to the battery, in such a way that each power source does not "see" the other (common ground, two diodes in parallel from panel+ to battery+, two diodes in parallel from charger+ to battery+)
7) For the love of God, ground this thing (battery-, charger- and panels- to a metal pipe or a ground connector in a socket).
You now have a complete, if small, setup for only calling upon the power grid when your solar panels aren't cutting it.
This system can be dismantled into its components quickly, which is nice if you need to charge a battery or need an inverter.
Since electricity is so expensive[1] here many people could reclaim their investments in as little as 5 years. With the subsidies reduced, it may be 7 years. That's incredibly short if you compared Hawaii to the mainland.
[1]http://www.heco.com/heco/Residential/Electric-Rates/Average-...
That was my thinking when I bought a bunch of oil ETFs a few years ago.
Oops.
http://www.eia.gov/dnav/pet/hist/LeafHandler.ashx?n=PET&s=EE...
It's still rising faster than inflation, and on an island like Hawaii fuel oil is more expensive due to the shipping costs. Kind of surprised they don't use geothermal preferentially to solar, but I suppose that unlike Iceland they have a better mix of solar resources available there.
I know that as enlightened individuals we're supposed to respect all creeds, beliefs, and faiths, but frankly, I doubt there is anything that anyone can say to me that will make me respect the people who have (apparently successfully) blocked alternative energy production efforts because it will drain the power of their lava god. If it's true that I share more DNA with these people than I do with a chimpanzee, it's strictly a fluke of evolution.
(Edit: To be fair, some Googling suggests there are some more tangible environmental concerns with geothermal energy in Hawaii, but propitiating Pele appears to be a very real part of their argument as well. If we laugh at and ignore their legitimate concerns because of the 'Pele' argument, that's just as unfortunate an outcome as one in which religious nutters stop a worthwhile project in its tracks.)
I have been to Hawaii and many natives would rather bite their own hand off than touch a haole.
Oil is useful because it can be used to produce value. That value production starts at the margin, and there's a lot more you can do with $10/bbl oil than you can with $100/bbl oil, and more with that than $1000/bbl oil (and in case you question that, it's about the production cost per barrel of canola-oil derived biodiesel). Which is to say: oil prices might not simply increase with scarcity.
But price drives what sources are feasible for extraction. Early oil didn't cost much to extract, and its price was low. As oil's become harder to find and pull from the ground, its extraction costs (and minimum market price) in crease. Much of the extraction at the margin is only feasible because of high oil prices.
Ultimately you may reach a level at which the global economy is caught between oil that's too expensive to buy, and a market price that's too low to support exploration, development, and extraction.
Gail Tverberg's explored this dynamic in some detail:
http://ourfiniteworld.com/2013/07/01/inflation-deflation-or-...
Her principle thesis is that it's going to be financial and economic effects rather than energy per se which will spell the endgame.
Meanwhile PV costs keep going down.
Second solar has the problem that it creates a tragedy of the commons. This has been obvious in several European markets now. Once built, the electricity is free, but not continuous. That means that for the majority of the time, traditional utilities have no hope whatsoever of competing with solar prices ... and then comes the 10% not covered by solar or wind (it's easily more than 20%, but I get a feeling we'd get into an argument).
At that point electricity is needed from traditional sources. Of course, because of this they need to be ready at a moment's notice. Capacity needs at that point might vary from 10% of total to 100% of total, so you still need the same fossil fuel capacity you have right now. It doesn't have to run at full speed anymore, of course. It can't be turned off, because when renewables fail, they don't give you much warning (we're talking minutes at most).
Note that means that large scale renewable plants cannot be used to power homes, because of economics. The more of this you have, the less efficient the market becomes (because the smaller ones maintained "for free" by individuals can't be beaten on price).
It has other pros and cons. In the case of plant failure, the system is much more resilient. And in the case that something disables most small plants (say, an earthquake), the system is much more affected than today (because rooftop solar just isn't built to power plant standards). Double this effect for comparison against nuclear (which is built to withstand ridiculous stress for obvious reasons, and that means it can almost always simply remain operational during a disaster)
Here's the kicker :
(this isn't entirely true, it's only true if you "minimize" the storage component. A battery that can hold 3-5x the power that will ever be drawn from it will last 20-30 years -at least- under that load. If you load it up > 95%, you get 2 years at best)So we're stuck upgrading the grid ... Or making solar installations 2x or 3x more expensive than the currently are, and not just in money : you need battery chargers, space (batteries aren't small), maintenance, ...
So there's 2 things we "can" do:
1) do what greens suggest, and make the rates reflect the new cost structure. Of course that means effectively raising the rates on traditional electricity by a factor of 10 or 100. This will mean that anyone who doesn't have solar right before this happens is so thoroughly screwed it's not funny.
It will also disproportionately affect the poor. For two reasons. First, they can't pay for their own little renewable plant, and can't get the loan. Second they usually live in highrises that cannot be powered using renewables, except for the penthouse. If you think this is wrong, call up a picture of residential highrises in Hong Kong, you'll see what I mean.
It will also reduce the size of the economy. Energy is one of those non-negotiable things, with almost zero price elasticity. It's effectively a tax. Even more so because the government usually controls the other side.
Oh and, in toto (everything taken together), it's less efficient than centralized production. It's attractiveness (to no...
"Disconnecting from the grid is not realistic for most people, Chung said. The current state of battery technology means they have to be replaced after a few years, he said. And putting a system with batteries on a typical house would cost $40,000 versus $25,000 for one without the storage component, he said. Moreover, the battery portion isn't eligible for the tax credits."
So population on the grid does not fall. What mostly falls is the revenue from them. 90% of the time they're not paying (or even paying negative amounts thanks to the laws the greens forced through). The company can't disconnect them, and if the greens have anything to say about it, can't charge them. They need to provide backup power though, because the solar installations can't do that (without tripling in cost).
It does in the point I was actually answering to though.
I was answering the question; "I like option 3. Why is it a bad outcome for the average electricity user?", where option 3 is "Solar people buy batteries and don't return power to the grid."
You are basically saying you think there is a low likelyhood of the topic of the question someone else asked becoming reality. But I didn't propose how likely it was one way or another, I was just answering the question that they asked about the downsides.
That combines with selling 50-60% less in the limited deployment case, 90-95% less.
That means prices will need to increase by a factor 3 in the limited deployment case, factor 10-20 in the green's "dream scenario" case.
If your country has a lot of hydro (which has ramp times measured in seconds) this doesn't matter.
Additionally, clouds don't magically appear and obscure an entire cities sunlight over the course of a few minutes. They pass over cities, so as one area loses solar generation another is regaining it. Or maybe it's an overcast day where the the solar generation is at a predictable low level all day. Neither of those cases pose any problem to hydro or any other plant that can ramp up and down over the course of a few minutes (and every nation has these - you can't run a grid without low-response time generators)
In the case of plant failure, the system is much more resilient. And in the case that something disables most small plants (say, an earthquake), the system is much more affected than today (because rooftop solar just isn't built to power plant standards)
I'm not really sure what you're saying here. That distributed generation gives you resiliency? In Australia and NZ, if the grid goes down then your solar inverters turn off too so it doesn't affect the grid's reliability at all. I believe most countries have this requirement.
How does not being "built to power plant standards" have any effect? Your inverters are still required to generate clean AC, and if they can't match the grid closely for any reason they stop generating.
Yes... and that's precisely the issues here. How do you know when the grid is down? You'd see a drop across your grid connection? Makes sense. But what if the grid went down, but because all the local houses were supplying greater than 100% of the local load requirements, it never looked like the grid was down?
That's the challenge. As I understand it, power utilities are considering "smart grid" as a distributed control mechanism to kill PV interconnects in such instances. However traditional grid control is normally built very stringently to allow fast detection of issues and fast isolation/resolution with redudant lines. If you have one rogue smart control point, you could end up electrocuting the engineer.
* sudden change in supply voltage * sudden change in frequency (and rate-of-change of frequency) * sudden change in phase angle
You can't mask these signals and they are particularly pronounced on the section of grid that was affected (i.e. the part that is now blacked out). These (and more) are the specific effects that inverters monitor for, and they will disconnect if they notice anything unusual. Inverters aren't checking for the presence of a grid supply, they're monitoring it's health. Your local lines company dictates the trip limits based on your address and size/type of installation.
As for safety, compare some scenarios that a lines worker could actually find himself in:
1) he has turned up to a fault and found that a HV line is on the ground and the auto-recloser is still trying to re-liven it at periodic intervals. The voltages are so high that walking anywhere near the fault could result in him being electrocuted due to a step voltage. The power levels involved are high enough to cause a major explosion. 2) he has to open or close a circuit breaker in a switch yard. He has no way to know whether the breaker is going to explode when he racks it in. At least he probably won't know about it if it does blow up. 3) he turns up to a fault on a 230V line, tests it and finds that there's still voltage present despite the earlier fault. He visits the houses connected to that part of the circuit who have a grid tied inverter and manually isolates them before investigating further.
That last one is hypothetical, since I've never heard of an inverter failing to turn off and even if one did stay on initially it would very quickly trip on overload after trying to supply your house and your neighbors all by itself.
Testing the safety of a circuit before you work on it is an everyday part of the job for electricians. Finding that a circuit is still live is very common, and having one re-liven unexpectedly happens too from time to time. You just take precautions, wear protective gear, and do your best to minimize the danger.
We're already at grid parity for solar on a kWh basis in places like Hawaii. What's more, solar supply matches A/C demand. Reducing and shifting most of the demand with home automation will cost less than buying batteries. Some people will just disconnect from the grid, maybe even connecting with their neighbours.
The maintenance costs for the grid won't go down as fast as people dropping out, so retail prices have to go up -- engendering a positive feedback loop.
As far as energy being non-negotiable with zero price elasticity: this is true in the short-term. We've seen the same thing with cars - eventually people switch away from gas guzzlers. More efficient appliances and architectures take a long time to show their effect, yet they have just as real an impact on total demand.
It's hard to argue that inefficiency is good for the economy. In fact, proponents of alternative macroeconomic metrics cite the GDP's bias against efficient renewable energy as one of its flaws [1].
If you pursue a bigger economy without considering efficiency and the societal benefits of other labor/capital allocations, you run the risk of prescribing bad policies. E.g., a government can grow GDP just by hiring idle workers to dig ditches one day and fill them back in the next.
[1] de Graaf and Batker. What's the Economy For, Anyway?
This may not matter for renewables, as there's no fuel burned ... but ... I doubt it will turn out that way. So a larger cost will be much more efficiently distributed amongst it's users.
You might not notice them. Last time I took a plane, when landing I was surprised at the installations I didn't realise were there. Large rooftop installations are common on stores such as Walmart, Ikea and others.
http://www.alibaba.com/showroom/price-per-watt-monocrystalli...
(Lots and lots of homes would probably meet most of their usage with less than 10,000 watts of panels, but they also aren't paying $3,000 a year in electric bills)
This ought to be the best of both worlds for the electric grid, too, since solar generates electricity when load is at its highest.
However, the grid is not concerned with running efficiently, or with minimizing environmental damage. They're concerned about their net profit.
Profits on day-generated electricity are much higher than profits on night generated.
Unfortunately, not.
Demand peaks early morning and early evening, when solar is near its minimum. And in winter, solar is near zero at those times.
So solar net metering has always been a bad deal for the utilities when you take into consideration the fixed costs they have for maintaining the necessary reserve to cover peak usage.
Note that Hawaii is (mostly) below the Tropic of Cancer, so gets quite a lot of solar radiation even in the winter, and the length of a day only varies by a couple hours throughout the year ([1], [2]). I don't know the math offhand, but even without adjusting the panels, I'd expect that the winter output is probably pretty significant.
[1] http://www.timeanddate.com/worldclock/astronomy.html?n=103&m...
[2] http://www.timeanddate.com/worldclock/astronomy.html?n=103&m...
It's not just about sunrise and sunset, but UV index and cloud cover. Here's some actual data on actual solar generation:
http://www.nrel.gov/gis/solar.html
This shows that even on the sunnier Oahu and Maui, solar generation is more like Nebraska than California.
The fact is that sunny days drop about 30% in the winter and UV index is down.[3] I wasn't able to find real-world MWH in Hawaii per month, but I'm guessing it's about a 50% drop overall with some days actually at ~0. Certainly not 0 for the month, but the fact remains that you need backup power for low-solar periods with more capacity if you want to leverage excess power in high-solar periods.
1 http://www.currentresults.com/Weather/Hawaii/annual-days-of-... 2 http://www.currentresults.com/Weather/Arizona/annual-days-of... 3 http://www.weather-and-climate.com/average-monthly-Rainfall-...
Your guesses are way off.
That might be true in some places, but neither point is true in Hawaii. Insolation is nearly the same all year, and grid loads peak midday with insolation (think AC): http://www.heco.com/vcmcontent/StaticFiles/Images/Articles/t...
The terms of almost every net metering plan are in the power company's favor, even if the net meterers somehow never bought power.
Net metering, as currently implemented, only allows you to earn credits on your bill up to the point where your maintenance fee kicks in. You're earning credits by producing power for the company during the day, when power is expensive. You're burning those credits to keep the lights on at night, when the company's cost of power is nonexistent. No one is paying net meterers market rate for time of day, so the power companies are coming out way ahead on cost of power. Even if that weren't the case, they still baseline your bill to a maintenance fee.[1]
Moreover, Hawaii has never had any clue how to balance a grid, so if HECO is now blaming customers for problems with the terrible system they built, my default position is skepticism.
[1] HECO's net metering bill guide, including the minimum monthly fee even for no power use: http://www.heco.com/vcmcontent/EnergyServices/NetEnergyMeter...
Don't get me wrong. Only some power companies are awful monopolies that barely do their job, most work fine. Still, those awful monopolies should face some threat of revolt.
This is a nice scheme around and between the tropics, and just about nowhere else. Because you need not just abundant sun, but abundant sun year round.
Temperate areas would need to lean on storage more. As generation efficiency increases, storage losses matter less. As storage technologies improve, poor insolation matters less.
But sure, someone invents a nice kitchen-sized baseline reactor that anyone can run, then this microgrid movement really takes off. Probably not in the next couple weeks. ;)
1) Who will respond to outages and make repairs. This includes issuing clearances to crews making repairs. 2) Who will issue protection settings (reclosers/relay settingsfuse coordination, etc) and perform fault analysis? 3) Unless you have generators then they'll need to provide power when your PV systems don't meet demand 4) Someone needs to investigate power quality problems 5) Generation dispatch to meet demand and maintain a system frequency of 60Hz. 6) Someone must handle interconnection requests. Who is going to stop your neighbor with a 50Hz generator that can handle 50% of your microgrid load from connecting to the system, causing a big frequency drop and damaging appliances? Your microgrid doesn't have enough inertia to absorb something something like that. 7) Are the micro grid operators subject to the same reliability requirements as utilities? 8) Are you going to install your own poles and wires? That includes permitting, responding to joint use requests per regulatory requirements, etc.
If our default position were microgrids, we might wonder of a unified system, "but how would you prevent cascading blackouts?" The current answer is you don't, major cascades just happen around once a decade.
It's all a series of tradeoffs, and I agree with you, usually the tradeoffs favor bulk generation. The balance shifts when monopolies abuse the public trust. So here, things like load balancing are an interesting example, since that's not an area where HECO has always excelled. UCSD is using a microgrid because they can't achieve sufficient reliability from California's bulk power system:
http://www.bloomberg.com/news/2013-10-17/ebay-to-ellison-emb...
Phasing for lines is checked by a rotation meter, it is either A-B-C or A-C-B. Get it wrong and your motors spin backwards.
That doesn't seem too bad.
There's no (legitimate) reason Hawaii's electric should be so high. They just have no incentive to reduce prices, and they have to keep their 6-figure salaries. I knew plenty of people that wanted to build solar/wind farms, but the electric company either wouldn't accept their electric at all, or would give them pennies on the dollar.
For the prices, if you'd ever been to HI you wouldn't be surprised. Everything costs more there, a lot more. Again, it's several thousand miles from the nearest major landmass
https://www.google.com/finance?q=NYSE%3AHE&fstype=ii&ei=r7C2...
I personally think that that's the reason the brakes are being put on PV, and not the populist "robber baron" explanation offered by the article.
Unless we reconcile those, we'll see a death spiral for utilities.
If the grid operator is primarily concerned with profits from peak generation hours, and trying to prevent solar from impinging upon that, it doesn't seem reasonable to legislate a way to protect those profits, ESPECIALLY not when it is environmentally damaging to do so.
The second would be a huge problem. The first is something lots of people are going to complain loudly about.
Resorting to doing that just drives people onto solar on mass.
It sort of seems like the two big inflection points will be solar getting so cheap that it pays for itself in a few summers and neighborhood or household scale batteries becoming practical.
Ultimately, they should be re-nationalized. Privatized utilities' incentives are completely screwed up.
If we are fortunate and can get to reasonable "supercap" sort of technology this will become easier.
I note with some interest though that most roof top systems put only enough out that they could, in theory run a Tesla Super Charger to a Tesla battery supply. You could then pick a point in the afternoon where you did the 'switch' and switched over to inverters running off the Tesla battery pack. Providing electrical load from that point until it got below a set charge point on the batteries. Some days you'd probably go from 4PM to 9 or 10PM, others only until 6 or 7. But you would get the benefit of not having to pay for that power when you were running off the Tesla. Elon if you're reading this you should figure out how to make that happen, you'd get better volumes on the batteries with Tesla (better economics of scale) and people could do this without utility participation.
With a super capacitor charge is stored as charge, and in a battery charge is stored by a reversible chemical reaction. The challenge of running the chemistry back and forth in a battery is what causes them to wear out eventually, and limits charge and discharge rates.
When we put solar on our house we looked at putting in a whole house "ups" as it were (the typical off grid setup was not unlike a data center, batteries that carried you until you could get on to generator power) The maintenance and replacement of those batteries is a pain.
But in terms of kWh stored and power delivery ability, the packs we were sizing were not unlike that of a Tesla Model S (65 - 75kWh) and Tesla has already got a replacement and refurbishment plan in place, and the packs themselves need no maintenance under normal use. So it seems like an interesting pre-packaged solution, except you'd need a high efficiency house inverter as well but progress there has come from the solar investments.
When using renewables you must still generate a majority of your supply from a big rotating generator. The inertia of the spinning generator keeps the frequency from straying from 50/60hz.
In Ireland they broke a record a few years back for having 50% of the electric generation coming from wind power. This was at the upper limit set by the grid operator (eirgrid) because above this level the frequency of the grid becomes unstable. Even though more wind power was available they didn't add it to the grid.
On average though 2013 renewables provided ~17% of total demand [http://www.eirgrid.com/media/EirGridAnnualRenewableReport201...].
System Non-Synchronous penetration (SNSP) is a real-time measure of the percentage of generation that comes from non-synchronous sources, such as wind and HDVC interconnector imports relative to the system demand. In the Irish grid this is limited to 50% for stability.
The biggest issue with wind is that the wind gusts so power output is variable.
As regards to frequency until your system has enough mass to influence the rest of the grid, the grid frequency is dominate. Even a 2,000 MW generation facility will not influence the grid frequency much, which is why it is important to sync to the grid as you connect.
I think the moral of the story is that people are way more enthusiastic about installing this kind of thing than rational analysis would estimate.
The traditional electricity network is a bunch of interconnected star-shaped networks, each with a large power station in the middle. You now not only have to get bigger power lines to where the decentralized "power stations" are, but you also have to increase the overall interconnectedness, to avoid instability (think parts of the network going out of phase with other parts, localized overload and so on) due to the volatility of the renewables.
Unlike Australia, some countries with unevenly distributed renewables do indeed also have to massively increase their overland capacity (central Europe).
In the Australian context -- as I understand it -- the Privatization of the Electricity Generators was such that they are legislated to only charge a fixed % of their costs. So the only way for them to make more money is to increase their cost-base (aka "Gold Plating") and then charge their customers the additional fees.
Only in neighborhood circuits where residential PV is significant. Utilities don't want to. Government should force them.
http://www.bloomberg.com/news/2011-09-29/utilities-giving-aw...
Why not set up a system where energy companies install and maintain solar panels on peoples' houses and then charge for the maintenance as a service (as opposed to individuals paying for their own panels in order to reduce their power bills)? That way they will be incentivized to not only offer solar power, but to invest in technology to also make it more efficient. Also individual home owners will not need to outlay such a large initial cost.
Does anyone know if utilities are changing their installation design books? To me that would be the first place to start. I don't know about Hawaii but I know in other parts of the US massive subdivisions are being put in on a regular basis. I would hope that those new subdivisions would be geared to support this use case.
If we're generating 2kW, and only using 600W - the excess of 400W is not fed back into the grid; it goes into an immersion heater and gives us hot water.
That saves us on burning natural gas, and prevents problems with the grid.
Now, depending on where you live, hot water may not be the most pressing problem. But it's slightly more practical that spinning up a fly-wheel :-)
[0] http://shkspr.mobi/blog/2013/12/free-money-from-the-sky/ [1] http://www.solariboost.co.uk/
Lateral design: typically a load curve is used to calculate the maximum load for each service point. The system is typically designed to handle close to that amount. If a house has a 200 A main breaker then it can use up to 160 A of current (unless the NEC changed since I did this type of work). Typically a house will never use 160 A even at peak load, but better safe than sorry so a 37.5 kVA transformer is probably used.
The power is designed to flow from upstream (substation) to downstream (point of service). The system protection (reclosers, fuses, circuit breakers, etc.) are designed to interrupt over-current from the downstream headed upstream. The exception to this is a network design where protection is designed to protect equipment in both directions. Network design does not happen much at the distribution level, although it is used in major cities.
If customer(s) are(is) adding power to the system then at a certain point you will have reverse power flow. And if the system is not designed for this, then bad things could happen and customers are not happy when the electric company causes damages. So the utilities want to be careful.
If the rate payers (customers) want a reliable system with the ability to feed power back onto the system then there will be a cost associated with it.
For the most part utilities have a monopoly granted by the state and are good at lobbying to protect their interests. What is best for the customer might not be best for the utility.
So, be it information or energy I can't help but notice the similarities there. Our networks were essentially designed, decades ago, for mass production and consumption, I have no doubt we'll end with more distributed energy production and storage means similar to what happens with the rise of fast, symmetric Internet connections but in the meantime we'll see a lot of these stories while the evolution finds its way.
Regarding the electricity consumption, we have access to the French realtime data online [2], I don't know if there's the equivalent in the U.S., I'll be curious to see the data for Hawaii. It's interesting to note how the daily consumption patterns differs between summer and winter (we have a lot of electric heating in the winter and little, albeit increasing, AC in the summer). Obviously there's a limit to how much PV you can plug on the grid without proper storage but it doesn't seem that's already a problem.
[1] https://news.ycombinator.com/item?id=6949326 [2] http://www.rte-france.com/fr/developpement-durable/eco2mix/c...
If the grid wont take you I wonder if someone could use solar panels during the day and use the generator at night. Wouldn't that be cheaper than batteries?
Buy some good deep cycle batteries and store your own power off grid.
I live in an area which HECO has chosen not to serve, so that solar is a no brainer.
$0.49 per Kilowatt Hour is what HELCO (Hawaii Electric Light Company, HECO's Hawai'i County subsidiary) charges, which is the highest price for electricity in the USA.
I certainly don't need a $35,000 solar power system, I'm getting by on a system which cost me about $5k.
My basic needs are refrigeration and lights, as well as power for small electronics.
For high draw appliances I use a gasoline powered generator. (washer, propane dryer, power tools, etc)
Screw HECO!
And that's after I spent three hours shovelling off as much as I could before the ice storm hit us today.
It snow 15cm before the ice storm now I'm back to square one.
I'd like to have solar panels but I can't see how I could keep them from being covered in snow without shovelling them off off at least once per week Dec to Feb.
If you answered any of these, you're wrong. The number one priority (at least in the utility I contracted at) was safety. Safety was front and centre in almost all design decisions related to power system control, and was the dominant company culture. Even "low" voltage distribution of 230v is dangerous without the correct equipment and training.
Let's put aside the issues with local transformers and substations - at the end of the day, AC power are relatively straightforward systems (though they are far from simple). The control of those systems is, actually, quite complex, and deals with multiple failure states. Adding PV supply into the mix is problematic. Though well studied, it appears that without better electical signalling (for example, overlaid at the local sub/transformer), Islanding will continue to be an issue.
http://en.wikipedia.org/wiki/Islanding