The issue here is the mandate that when you create electricity with solar that the electric company must buy that electricity from you as you feed it back into the grid, regardless if they currently need it or not based on demand. These power companies dont want to become energy storage companies, its too expensive. They prefer to simply make as much electricity at the moment as is needed.
I agree with the electric companies on this point. If they dont need the electricity, why should they be forced to buy it? That will increase costs for non-solar customers as they end up footing the bill for the battery storage needed by solar customers. I think the proper way to do these installs is to have customers always have on site batteries which store the energy for their own homes use. Yes, its nice to sell back electricity to the grid, but that feels like a very hackish way to use 'solar'. It makes sense also. If you want to save money on your electricity, you need to make your own, so you draw less from the grid- Not make it for someone else when nobody wants it.
Does anyone know if the power company is required to buy all forms of electricity currently? Could you just setup thousands of solar panels in a field you own and demand money from the grid? Seems like a easy return on investment, depending on the cost of panels/equipment.
Most net metering programs take solar from a home when the grid is facing its highest demand and energy is most expensive for the power company. They then provide a credit to your bill in watts. With a solar installation, you're drawing energy at night, when the grid basically wants to give away power to keep things balanced.
So you contribute a dollar worth of power, and you take out the same power at a later point in time, and the power company basically gives you a 5 cent credit.
The power companies make fistfulls of cash on the arbitrage.
They still hate it though, because distributed power generation threatens the model of power monopolies that get to fix prices while steadily reducing service.
Hawaii in particular has faced historically terrible load balancing, so some of the distributed generation is a response to the poor existing services and constant outages. HECO basically created all the incentives for the public to hate and want to work around them.
You couldn't just give them an out on whether they wanted to buy the power or not, since they despise distributed solar generation. They'd just build a messy and expensive quick spin up generator, buy expensive power from that during midday, and claim they don't "need" the solar, to deter investment in the technology, even though it'd be better for everyone if they bought the solar.
You can't ask a kid how much he needs foul tasting medicine. Sometimes you just have to deliver it.
Have an uncle who works in power. The way he tells it the power companies are happy with supplemental power during peak loading because peaker plants are unholy expensive, but said companies are worried about what is going to happen when everyone is doing it.
It's like electric cars & the gas tax. Electric cars are great! But gasoline taxes paid at the pump are a major source of funds for road maintenance, and electric cars pay none of them. That's ok for now because so few people have them. And that's not to say we don't want electric cars. But we better figure out how to handle them before half of the population is driving them and the DOT is faced with a major budget shortfall.
In CA, at least, net metering is in $, not Watt/hours. So I can push 1kWh to the grid in the daytime, when rates are high (typically $0.35/kWh), and pull at night when rates are low (typically $0.10/kWh). Thus, I can reduce my net bill to $0 while still being a net consumer on the grid.
You state the following as a given, which is exactly what your parent says is wrong.
>Most net metering programs take solar from a home when the grid is facing its highest demand and energy is most expensive for the power company. They then provide a credit to your bill in watts. With a solar installation, you're drawing energy at night, when the grid basically wants to give away power to keep things balanced.
Do you have a source that states production from solar meets peak demand?
In Hawaii, solar meets peak demand during the summer, as in the summer they have a higher midday peak than evening peak. In winter the evening peak is slightly higher, however if you look at area under the graph rather than just at the peaks, it is obvious that solar correlates pretty well with usage in general in Hawaii.
We can take it as given that solar panels produce the most power during the day, particularly when the sun is directly overhead. The assumption is that air conditioning and refrigeration is a major electricity use that consumes the most power when the sun is shining. Presumably that is the case for residential, office, retail, and most service industry use. There are industries whose electricity use is not correlated with time of day, but they're not based in Hawai'i. If you want evidence that the damnedpowercompany would like to give away power at night, take a look at their awful "security light" programs.
I've seen a couple of things recently that said that peak consumption (in California, at least) is in late afternoon and early evening, as people return home from work and turn on their air conditioners and other appliances. It's not right in the middle of the day, as you might think.
Probably depends on where in California. If you look at google maps in SoCal, it seems like almost every house has a pool. Pool pumps take a lot of power, and you're supposed to run it during daytime. Those 4-6 hours its running is our highest power usage.
I can literally look up my hourly power usage online. The 4-6 hours my pool pump is on is almost 2x higher power usage than any other time. I consider that a lot of power.
Edit: we had our house unoccupied for 2 months with everything unplugged and off, but our pool pump and sprinkler system. Based upon that, and looking at our historical usage, I would say our pool pump accounts for about 65% of our monthly kwh.
Wow, it surprises me that it's that high, but you clearly know your numbers. Presumably the rest of your house is quite energy efficient?
If it something that interests you, you could probably reduce the power usage considerably by switching to a smaller pump that runs for more hours. All else equal, the power required for pumps increases much more than linearly (proportional to the cube of the flow), so a pump with half the flow rate that is run for twice as long would use less than half the total energy per day for the same amount of water circulation.
That's not the case for residential, office, an industry use. The hottest time of the day is when electricity tends to peak in hot climates, which is not when the sun is directly overhead. It's usually later in the afternoon.
That's not at all what that report says. The graph in the report is talking about the energy usage and production of one household, not global demand. Peak global demand of energy in Australia is very much in the middle of the day as offices and other workplaces run aircon / lighting / computers / industrial processes.
>I agree with the electric companies on this point. If they dont need the electricity, why should they be forced to buy it?
A) Because they are operating a utility monopoly. We are forced to be their customers. They should be forced to be ours.
B) They could use it, but they would rather sell you the output from their oil fired power stations because the profit is higher for them. That is why they don't want your solar panels hooked up - not because your neighbors couldn't use the electricity they generate - because it challenges their monopoly position and eats into their profit margins.
If this were truly about electric companies not needing the electricity (as opposed to them viewing any challenge to their monopoly as a 'free market evil'), then they would be arguing for market pricing for your solar generated electricity. They are not. They want your solar panels to be completely disconnected. Ideally you shouldn't even have them at all.
>Yes, its nice to sell back electricity to the grid, but that feels like a very hackish way to use 'solar'.
Your argument for how energy policy should be set are informed by what you think "feels hackish"?
I'm really surprised people on HN don't see the complexity of having distributed power generation that you have no visibility on. I don't really think this is as trivial a problem as people seem to think it is.
As for the situation of selling power back to the grid, I would argue the solar users are still the customers. The power companies don't want it because the changes need to be paid for by current customers but only benefit ex-customers. The solar users are using the grid as a giant battery and an insurance policy for cloudy days.
If the power companies are paying what they charge, then the laws of physics say they are losing money due to losses to heat, etc. So of course their margins are higher on their power.
>I'm really surprised people on HN don't see the complexity
I never said it was a trivial problem. I said that it was a problem that the utility companies have a vested interest in not solving.
I'm really surprised that people on HN are blind to this.
>The power companies don't want it because the changes need to be paid for by current customers but only benefit ex-customers
This is false. The power companies do not want it even if it is paid for by current customers because even if it is, it eats away at their profit margins. Every kwh generated by a home owner's solar panel is not a kwh they are being paid for, even if they just use it themselves and don't transmit it across the grid.
At least in Hawaii there are a lot of independent energy producers, so your statement is appears to be wrong that they only want to sell their own power. While the majority is their own, it looks like 35%ish is independently generated.
They don't want to buy back power at the same rate they sell it, and since they can't control the nodes - the power from solar panels on homes is less valuable than that from larger independent producers since it costs more to control a distributed system. I'm sure they would buy it back, but people will be very angry about what they're willing to pay.
People are also free to get batteries if they don't like what the market prices are for buying electricity.
> I never said it was a trivial problem. I said that it was a problem that the utility companies have a vested interest in not solving.
They probably would solve it, but they know that the cost of solving that subtracted from the rate they pay their energy producers is low enough that people will complain and it's not worth it. They probably come out ahead by not solving that problem, I'm not sure how you can mandate they solve a problem so people that want to go "off grid" don't have to buy their own batteries. That's really what they're trying to avoid - there is nothing preventing people from going completely off grid, they just don't want to buy their own batteries.
>At least in Hawaii there are a lot of independent energy producers, so your statement is completely false that they only want to sell their own power.
They're not doing that because they want to.
>They don't want to buy back power at the same rate they sell it
They don't want to buy power at all. Certainly not if they have existing capacity that they would rather use. Definitely not if it is a future threat to their bottom line.
>People are also free to get batteries
Batteries are a much more inefficient way of using power than selling it to your neighbor.
>They probably would solve it, but they know that the cost of solving that subtracted from the rate they pay their energy producers is low enough that people will complain and it's not worth it.
Let's not pretend they're not solving the problem for our benefit. This is about their profits.
>I'm not sure how you can mandate they solve a problem so people that want to go "off grid" don't have to buy their own batteries.
Because they are a monopoly and a utility. We mandate they solve problems because otherwise they will just milk their monopoly for all its worth and the only party that benefits from that is them.
I think you hit the nail on the head. Their monopoly is in jeopardy and they aren't happy about it.
Hawaii tried geothermal, but for some odd reason it made a loud whistle sound when letting off exhaust. People didn't like that, so the idea stopped cold.
I'd have just had some shitty engineer spend ten seconds proposing an easy fix for that, but then again if the power company gave me millions NOT to do that, why would i?
> then they would be arguing for market pricing for your solar generated electricity. They are not.
Market pricing is exactly what a lot of utilities in the EU are now pushing for. Solar panel owners don't like it, because market prices now frequently dip below zero when solar and wind peak simultaneously.
The second issue is the cost of providing and maintaining power transmission. Traditionally, the utilities just tack on transmission costs on the electricity costs. When everyone buys all their electricity from the utility, this is a reasonable compromise. However, when you get rooftop solar, the cost of providing power transmission to you doesn't go down at all, yet your electricity purchases do go down.
A fairer way to price electricity transmission would probably be by your maximum draw from the grid, or by the size of the fuse that connects you to it.
A fairer way would be to treat electricity transmission as the natural monopoly that it is and to ensure that companies that do generation are not involved in transmission and vice versa.
Transmission would be better handled by local government. If they want to favor homeowners' solar panels, so be it. If they want to favor the local power plant, again, so be it.
If you let generators run the grid then they will do everything in their power to kill any forms of competing power and they will succeed thanks to their monopoly power.
There is no intrinsic reason why rooftop solar shouldn't be given subsidies (direct or indirect), also. It is greener than almost all alternatives, after all.
> A fairer way would be to treat electricity transmission as the natural monopoly that it is and to ensure that companies that do generation are not involved in transmission and vice versa.
That's exactly how it works in Finland and a lot of the rest of Northern Europe. I buy transmission and electricity from different companies.
If the entire point of installing solar is to offset the cost of your own electricity, it seems like a incredibly stupid investment.
You are basically paying tens of thousands of dollars to shave $100 off your electricity bill every month. You would do far better investing your money in normal things and just using the profits to pay your electric bill.
If you want solar to not be reliant on the grid, you need batteries. If you want solar to be a investment that gives you xx$ of benefit a month, you should look into doing something besides solar.
Having just gotten our PV panel installed on our roof this year, this is fresh in my mind. Of course everyone is doing it -- electricity in Hawaii is insanely expensive. Before we turned on the system, we paid $200/month for power! And this is in a house with no heat and no AC.
Do they have to buy the power? Yes, but not without limits. The system is built on "net metering". Every kWh we deliver to the grid can only go to offset one that we already have or will use. If your system is so large so as to make you a net producer of energy when averaged over a whole year, you will be giving that away to the utility for free.
The rules also limit installation of PV systems to a level that will not exceed the minimum daytime load on the local circuit, exactly because there is nowhere to store the power. So every kWh they get from us is one they would otherwise have to generate to supply to one of my neighbors.
It's clear that the utility companies aren't happy with this. But studies have shown that these "extra costs" the utilities talk about being saddled with are offset by savings to them as well.
Solar power typically produces power during times of high power demand, so the net effect of solar is actually to even out the daily load variance. This is good for the utility because they need to make sure they have capacity to handle peak load, even if it's only for a small fraction of the time. These "peak power" plants are expensive, because you almost never get to operate them. When PV reduces peak load, they don't need these plants and this is a net win for them.
Could you just setup thousands of solar panels in a field you own and demand money from the grid? Seems like a easy return on investment, depending on the cost of panels/equipment
This depends on your jurisdiction; in the UK you can put up to 4kW on an inhabited building and get a subsidy. Larger installations require pre-approval.
You are conflating the electricity producers with the grid. The grid itself actually saves money by installing storage, when compared to upgrading links, and does so when it can.
As to, if they do not need the power, why should they buy it? Well, there are two reasons, one is that everyone else on the grid already gets to, so it would be anti-competitive to not allow it for the little guys, and the other is that someone will always want power, so it makes economic sense to buy the power and build storage to offset it and make money through arbitrage.
Hawaii is a particular shit show when it comes to electricity utilities. From their own page on renewable energy, no less:
Electricity can be made from a variety of energy sources. Some are fossil fuels such as oil, coal and natural gas. Over 90 percent of all the energy used in Hawaii for electricity, surface and air transportation comes from imported fossil fuels, mostly oil but some coal. (The synthetic natural gas used in Hawaii is refined here from crude oil.)
I think nobody here has the patience to wait for this particular dynosaur-consuming monster to catch up.
I think it's been clear for the last fifteen years that oil for electricity generation is untenable. My only remaining concern is that it will take far far too long to unhitch a utility company that has already clearly demonstrated it has no interest whatsoever to change.
Was oil a bad choice when there were no affordable regenerative methods? Probably no. My concern isn't with their initial choice, it's with their more recent choice to fight solar and other regenerative energy sources instead of embracing them.
The facts are evidence of electricity being very very expensive in Hawaii, to the point where even the most unfavorable policy on solar in the western world makes installing solar a very worthwhile investment if you have the space and upfront cash. Of course this state of affairs tells you a lot about HECO. You have to be a special blend of incompetent if you can't use solar in a place where air conditioning makes up large swaths of load, which has this funny synergy with the sun.
In a parallel line of discussion you would presumably tell me the increase in heroin consumption is evidence of a more welcoming stance on its use in society. No, its just such a powerful drug that the DEAs activities only increases the number of addicts.
Hawaii, if you actually sit down and look at where the geothermal resources are (big island and a tiny amount on Maui, not where 90+% of electricity is used on Oahu), will force you to conclude that they couldn't copy Iceland and are stuck with other renewables.
The distance from the big island to Oahu appears to be feasible for an underwater HVDC cable (eg http://en.wikipedia.org/wiki/Basslink ). If the geothermal was cheap enough, this might be worthwhile.
I think that your very valid point IS the critique. Having power grids "last centuries" was a noble endeavor, however, it is now a hinderance.
The idea that customers should care about the utility company's long term investment, in their 100 year grid is not a good one. Consumers shouldn't have to care about a companies long term investment "paying off". All that means for the company is that their investment failed, and they need to try again.
It seems inevitable that continued advances in PV will either destroy the power utilities or force them to reinvent their business as electricity brokers (focusing on distribution and/or storage).
Regulatory capture can slow this trend. But as the article indicates, it's only temporary. Advances in energy storage and moderated consumption allows customers to disengage from the grid entirely.
I feel like this is one good example of big changes coming to the world and traditionally established big business in the next 5-10-25 years. Hilariously, many of the following big business have "guaranteed profits" from the Government, which is also going to have to change.
If you're in the business of making electricity by burning stuff, or you sell oil, or cable TV, or internet, or 50 other good examples, you had better start reinventing your business now.
Those business make very rich people richer, so they're going to fight it tooth and nail, which is a shame when they could be putting that effort into reinvention.
>Hilariously, many of the following big business have "guaranteed profits" from the Government, which is also going to have to change.
I doubt that will change. If you want companies to have enormous amounts of idle capacity waiting around for a cloudy day then you have to make sure they can make money.
We're not going to need that capacity anymore, so we don't need the companies anymore.
i.e. when the massive majority of houses and business have their own solar and storage, we don't need to pour billions into coal plants and the grid to have it sitting around waiting for... nothing.
I don't see how that will ever make sense. The only way you can guarantee your house will have enough power is to overbuild the storage by quite a bit. It's not worth the money.
When the majority of houses have a good amount of solar and storage, then the grid we already have will be more than enough, therefore it can go into "maintenance" mode. (likely even reduction, I suspect)
I agree. If I were a utility, I would be working hard to figure out how to be a storage broker, because if homeowners figure out storage without the utility, the utility will eventually be left with nothing other than large industrial consumers (which might be a decent business, but probably less than half the size of the utility's current market).
Isn't Hawaii a special case because of its isolation?
If so many people install solar in Southern California or Arizona that the local utility has more power coming in during the day than it can use or store, it can sell the excess via the national grid to someplace that can use it.
As far as I've been able to determine from the internet, there is no connection between Hawaii power grids and the mainland. In fact, it looks like the grids of each island might be isolated from the others.
Exactly. None of the islands grids are connected. I worked for a power plant on the big island a few years ago and even then there was a big issue with too much power during the day and not enough at night. Coupling that with the intermittent wind power and you have a very hard grid to maintain.
NextEra (the energy company that recently bought HECO) is looking to do just this. A Sept. 2013 report by them estimates a capital cost of approximately $600 million for a 200 MW cable connect between Maui and Oahu. (source page 8 of [1])
This is the low end of the scale with other estimates ranging from $553 Million to $1.24 Billion (page 9).
Note that this does not connect the Big Island to the grid either.
The preliminary proposed route can be seen on page 84 of the report.
I think that a home battery product from Tesla might help with some of these worries. If the rumors are true, Tesla want to take their existing car battery technology and turn it into a wall mountable product. This would allow homeowners to generate their own electricity during the day and use it at night. I'm not saying that people will completely drop off of the grid (though I'm sure some will) but it might be a way for the utility companies to manage peak demand. There is possibly even a good small business idea in building software to handle this type of thing.
The cost is still too high, so the electric companies have little to worry about in the short run as long as they can find ways to improve their own margins. Of course lobbying for regulatory fees and reduced buy-back rates is one way to do that, but the utilities best be careful there. That could cause a blow back reaction.
In the long run though it is all downhill. Battery tech is getting better at around 8% per year. Solar efficiency isn't far behind. What cost $20,000 now to add solar or $40,000 to get off-grid completely, will cost half that in about 10 to 15 years. If the trend lines continue then in 20 to 30 years years its a done deal. No house will ever be built again without it's own power generation system.
You can't get off the grid completely unless you are a) willing to suffer some downtime occasionally, b) way overbuild storage as compared to typical needs, or c) have your own backup fossil fuel generator.
Any way you cut it high availability costs money. If you expect the grid to handle backup for you then you should expect to pay them to do so. TANSTAAFL
On (b), in addition to total capacity (kWh) you also need to have the battery system designed for quite high transient discharge rates (kW). A typical American suburban house pulls well under 2 kW on average, but can have transient usage spikes in the range of 15-25 kW or so, depending on the house. It's doable, just requires an even more oversized/expensive system.
An alternative could be to avoid simultaneous usage of the major appliances (A/C, electric oven, vacuum, washer/dryer, tea kettle, etc.), of course. That would probably require a mixture of behavioral changes and changes to the A/C system. For example a house with multiple A/C units (window units or upstairs/downstairs) could have them wired so they don't kick on simultaneously.
I don't think (a) is true because (b) and/or (c) is exactly what people will eventually do --although in the case of (c) it will be hydrogen fuel cells.
It costs at least some $400/kWh for battery storage. That amounts to $12k dollars for each house for supplying average consumption; that's a huge cost already. If you want (a) to be false, I guess you need to multiply that by two at least. It just doesn't make sense to make each house do it individually, the grid is a wonderful technology that reduces this risks, smooths consumption and provides storage/generation economies of scale. It just doesn't make sense to abolish it entirely for all but the most isolated places.
I pay about $150/mth on electricity ($1800/yr), if your numbers are to be believed, then it would take about ~13.2 years to pay off a 24k battery pack, this doesn't include the cost of the panels which would probably be another 24K, so roughly a 26 years to pay off (Probably the working life of the panels) So basically at current prices the cost is on par with my utility. It's not amazing, but with the right gov't incentives and future advancements in battery and solar technology I don't see why we couldn't see renewables edge out the dominant players. Sucks for me though, just finished my B.eng in mechanical with specialization in thermal power generation.
I was just discussing this with someone who installed solar panels on their house about 8 months ago. I think your numbers are a little bit off.
We live in south western ohio and said person took their bill from $300-400/mo to $30/mo (at 13 cents per kWh) with $11k of solar panels. They have a payoff period of about 3 years not including the $4k rebate they got which reduces the payoff cost to a little under 2 years.
Keep in mind this is a place that doesn't get nearly as much sun as much more southern areas/Hawaii.
I do agree that batteries still have a payoff period that is too long to be economical. Here's rooting for Mr. Musk.
It's based mostly on a recent paper in nature that estimates "that EV batteries in 2014 cost between $310 and $400 per kwh", but anticipates "It’s now in the realm of possibility that we’ll see $100 / kwh lithium-ion batteries in electric vehicles by 2020, with some speculating that Tesla’s ‘gigafactory’ will push into sufficient scale to achieve that."
His numbers roughly agree with yours:
So we’d estimate that at the following battery prices we’d
get the following effective LCOEs (Levelized Cost of Electricity):
- $300 / kwh battery : 33 cent / kwh electricity storage
- $200 / kwh battery : 22 cent / kwh electricity storage
- $150 / kwh battery : 17 cent / kwh electricity storage
- $100 / kwh battery : 11 cent / kwh electricity storage
All of those battery costs, by the way, are functions of
what the ultimate buyer pays, including installation and maintenance.
I once worked at a utility studying this very issue.
The typical worries about solar are:
+Power intermittency (rapid, uncontrolled changes in power can push the voltage and frequency outside acceptable levels. This reduces reliability and can destroy electronics.)
+Voltage regulation (also, on a local level, PV can mess with voltage compensators, pushing voltage outside of acceptable levels at the end of voltage regulation zones)
+Morning power surplus (lots of solar power will drop the baseline demand from ~4AM to noon, reducing the amount of cheap baseline power you can run)
+Harmonics (crummy inverters can inject unwanted sine wave harmonics into the grid, again bad for electronics)
+Fault current danger (if a tree takes down a power line, both sides can be remain live if power is being pushed onto the grid by PV on both sides)
+Inverter tripping (the main way to fix the fault current problem is to mandate that inverters passively follow the grid's voltage/frequency and then disconnect if they detect problems. However, with high PV penetration this has its own problem: a transient fluctuation can cause a domino chain reaction where all the inverters turn off, taking the grid down with them.)
+Power factor/vars (one important function for the grid is to keep current and voltage in phase, but today's PV inverters are dumb and blindly produce power with a power factor of 1, which can mess with automatic capacitor banks meant to help counteract the inductive load of the grid)
Now, some of these problems are more real than others, and many don't become an issue until PV penetration reaches like 30%.
The good news is that these are all solvable problems. Energy storage or additional natural gas peakers can fix the intermittency problem, and for the other problems the grid can be redesigned to allow better two-way power flow and inverters can be designed to produce higher quality power.
However, the bad news is that all of these fixes are expensive and all of them take years. Furthermore, many utilities do not have the expertise or confidence to make big changes to their grid and still guarantee reliable high quality power. Utilities are known for being slow and risk-averse, but they are risk-averse for a reason - blackouts are very costly to society.
Another issue for the utility is how to charge for power. Historically, utilities have tried to keep things simple for residential customers by charging only for power consumed. However, if residential PV becomes popular, utilities will have no choice but to change their pricing model so that they can be compensated for the non-kWh value they provide (e.g., reliability, stability, option value, power quality regulation).
The bottom line is that the problems from high PV penetration are real. Utilities are cautious, not evil, and they have good reasons to be. (Also, I think it's ridiculous when people claim that PV will kill utilities - barring a radical shift in technology/economics, wires and pooled power regulation and economies of scale make a grid hugely valuable, even if power generation becomes more distributed.)
That said, these are all solvable problems and I am hopeful and optimistic about the long-term future of solar power.
> However, the bad news is that all of these fixes are expensive and all of them take years
As a power electronics control engineer I strenuously disagree. The historical problems with massive renewable penetration aren't just solvable, they are well-solved already!
For example, grid-tied inverters and PFC rectifiers have been meeting IEEE-519 harmonics guidelines for many years already.
We even have virtual impedance methods which provide harmonic and reactive support for the grid available right now. The problem is that the utilities have actively blocked their implementation!
The grid accepted an almost total transformation from nonlinear RCD computer loads to PFC-corrected loads without difficulty at all, and there are far more switching power supplies on the line than there are active inverters. So I view the "problem" with unity power factor inverters as a red herring.
Anti-islanding has been in effect for many years already, which completely eliminates the "felled tree leaves live wires" problem. Again, another non-problem.
Consider very carefully what you get from the entrenched utilities, because they are coming to the table with a tremendous amount of preexisting bias.
I did not mean to imply that all of the typical worries were well-founded (as you say, harmonics has been solved for years), but now I realize that's how my comment read, so I apologize. My point was that there are factors other than intermittency that historically have stopped utilities from enthusiastically supporting residential solar.
Also, I wholeheartedly agree with you that the solutions to these problems already exist. When I said they'd take years, I meant it would take years to implement the solutions, not to invent them.
Unless they're already started up (i.e., part of expensive spinning reserve) gas peaker plants can't respond fast enough to solar PV ramp rates, which can be hundreds of MW/minute when clouds blow over a utility scale plant like Topaz (550MW). They take 10-15 minutes to come online from a cold start and sync with the grid. Gas peaker cold starts are expensive - the plants I've looked at (GE, mainly) allow some number of cold starts before the plant has to be taken down for service. But keeping them hot (spinning reserve) is expensive, too.
The fix for rapid PV ramp rate is enough storage at the PV site to give ~ 15 minutes of continued nominal output when insolation drops out. This is enough time for classical grid management tools to be engaged.
One driver for the equipment upgrades needed to deal with reactive power compensation, etc., is the price premium paid for "ancillary services", or power supplied at short notice for grid stability/management needs. The multiple over normal, average power pricing can be 100x depending on the circumstances.
When residential inverters are smart and can respond to utility signals, then residents can participate in the ancillary services market. That will (or should, at least) pay much more than simple net metering schedules. The economics should accelerate deploying equipment that can do this, and that will mitigate the problems brought on by high grid penetration of PV generation.
Wouldn't the solution to charging be the same as any other consumable utility? Charge x dollars per month for the base keeping the wires hooked up fee, and then x cents per kilowatt hour?
If you look carefully at your bill, you'll find that this is basically how it is structured in the US. Even commercial customers pay a demand charge (highest kW used in any 15 min period over the month, on the order of 10 USD/kW peak) for the site's peak power use plus a separate fuel charge (total kW-hr over the month) for their total energy use.
The issue is that the actual fuel charge for energy varies widely over the course of the day, and customers aren't exposed to that fluctuation. This leaves utilities to absorb the cost fluctuations, which turns them into finance companies as much as electric service providers.
I have a solar startup that specifically focuses on automating interaction with utilities, and the excitement and ambition in the solar industry right now is off the charts. There is an unbelievable amount of momentum in favor of solar, and most solar companies see these problems as totally solvable. Hawaii is seen as a microcosm for the way the rest of the U.S. will be in 10 years or less.
Here's some of the things that solar has going for it:
1. The Governor of California recently set a mandate to reach 50% renewables by 2030[1]. We want to hit this target in ten years or less.
2. The Department of Energy's Sunshot initiative is funding solar technology and software development to drive the installed cost below $1 per watt by 2017[2]. So far, we are on track to hit these targets.
3. Batteries are getting super cheap, which will turn solar into a non-intermittent source and allow solar+storage to be just as cheap as grid prices[3]. In fact, there is actually quite a bit of worry about grid defection (we are starting to see this Hawaii)[4].
4. Wall Street is funding solar projects at a massive rate[5]. The bottleneck right now in solar is finding customers, not financiers.
5. The federal subsidy for solar is expiring in 2017, but the industry is on track to absorb the cost and continue to thrive without any subsidy[6]. This will make us much harder to kill off politically.
6. The advent of community solar will solve the renting problem, where renters be able to buy pieces of a remote solar farm since they don't own their roofs[7]. This opens up the solar market to serve the entire electricity-using population, not just the building owners.
What will be hard:
Stranded assets. Solar is growing so quickly that it will soon be able to replace the capacity of existing fossil-based generators that still have lifespan[8]. Investors in those assets will see them stranded. This will start with coal and natural gas plants over the next 10 years, but as batteries get cheaper and electric cars get more prevalent solar will start stranding oil assets[9].
This is where things get hard. Utilities are traditionally pretty bad competing (since they usually don't have to), but oil companies are another story. They are very used to ruthless competition and have a lot of experience bribing their way into governments. We are expecting very heavy push back from oil after 2025 because electric vehicles risk leaving already purchased oil in the ground.
I, for one, can't wait until we fight that fight. It is the fight that our generation will be remembered for.
P.S. The entire solar industry is hiring (including my startup).
Is it really that hard to forecast the amount of power residential PV generates? I'm pretty sure you could build a model that is pretty good just based on weather data, but failing that why not just put a single small PV panel on each (plant, substation, power pole... choose your level of granularity) and have it report back the amount of solar energy in that location? That should get you a very good idea of the amount of power coming in.
If the utilities drag their feet, their could be reasonably good micro/neighborhood/apartment complex-level solutions - $100-250k of batteries on a loan & small buy-in per-unit, and the batteries & smart-system can optimize the buy/sell process around historical/current usage & prices & storage levels.
It is an interesting conundrum. I'm looking forward to whole house inverters with decent battery packs to take me completely off grid. At that point a simple fuel cell tied to the gas line to top off the battery pack when low on energy and you're good to go.
Can anyone comment on the claim that private solar power generation affects the stability of the grid? What kinds of infrastructure changes would be needed to properly support power generation in private homes?
There is a disconnect between market forces in energy production right now.
Right now, short-term grid frequency and voltage stability (periods of seconds to a few min) is regulated automatically by the governor response of the various generators on the grid. These governors bid in advance to set their proportional gain for frequency stability. Basically, they promise to autonomously raise or lower their throttle in the future based on the observed grid frequency and voltage, and get paid later when they make good on their promise. Long-term stability (periods of 15 min or so) are regulated with market action in the spot market for power. Very long term stability is regulated by markets that clear 24 hours in advance of their estimated delivery.
However, some energy producers effectively have flat rate contracts that don't participate directly in grid stability. Wind and nuclear will negotiate a fixed power-purchase agreement (typical prices are about 50 USD/MW-hr or so in the US) that will be fixed for years at a time. Likewise, residential solar customers sell back their power under the same, basically fixed rate schedule that they use to buy power.
So, as the penetration of fixed-rate power increases into the market, the pricing volatility continues to increase as well. There are technologies that can help. In fact, it is trivially easy to get a grid-tied inverter to be sensitive to grid changes with controls that model virtual inertia, impedance, throttle, and so on. This is part of what I do as a controls engineer. The difficulty isn't in implementing such controls, it is in adjusting the markets such that all of the existing players are comfortable with the result.
Witness this in Hawaii - the retail price of power is so high that it makes obvious good sense to install your own generation. But instead of adjusting the rates to reflect the new availability of supply, the incumbent utility seeks to raise barriers to competition instead.
...the retail price of power is so high that it makes obvious good sense to install your own generation. But instead of adjusting the rates to reflect the new availability of supply, the incumbent utility seeks to raise barriers to competition instead.
Incumbents elsewhere might find themselves in similar situations. If they react the same way, enough localized generation and storage will appear that they will find their business unworkable at any rate level.
The grid is built on the assumption of a few central points producing almost all electricity. This creates a grid focused on distributing away from those points. A more distributed and fluctuating producer situation will need more distribution between different branches of the network than the current infrastructure can handle. It will also require extra power generation that can be started on demand when the power production is lower (due to clouds, night, etc). This requires a lot of extra capacity that will get very low average utilization and therefore be very expensive due to being expensive to set up.
Well for one, whenever a power-line goes dead... the Solar panels need to shut off so that the workers can safely replace the powerline.
There's nothing quite like "Oh, some home in this neighborhood is still powering this powerline, despite the fact that we've shut off all the other power sources". That's quite the real "shocker" to the poor worker.
I suspect if this weren't the case we would already have heard about all the burned houses. There's nothing the media likes to hype more than something scary and new. Of course, this is why engineers and electricians are licensed.
anybody else confused about why a guy who lives in Hawaii, one of the most temperate climates in the populated world, is spending $700 per month in electricity?
serious question for Hawaiians: do people run the a/c round the clock there? Or is it something else?
I live on the big island and pay over $.40/KWH so a $700 bill would be more like $200 on the mainland.
That is one reason why my new house is off grid solar - cheap (compared to $.40/KWH), clean electricity.
The other is that the grid here is unreliable. I had 87 outage events last year for a total of 37 hours and that is not including the nine days with out power post hurricane.
Many people, at least on O'ahu, live in urban areas with serious "heat island" going on. In those locations, if your windows catch the prevailing winds, you don't need a/c, or perhaps only rarely. If there are buildings or terrain blocking the breeze, however, you'll be more comfortable if you have a/c, or if you make some lifestyle changes that make it less necessary.
That said, when I lived there, my bills never approached that figure, even with a/c.
My bill got up above $500 one month (normally around $350) without A/C. My friend's cousin on Maui had a new neighbor move in next door from the mainland and installed central A/C like every decent apartment on the mainland has. Their first month's electricity bill was $3,000 (three thousand United States dollars) because of that A/C. It gets very expensive, very fast.
It may not be A/C. A pool with a single speed pump plus an in-ground hot tub could conceivably run between four and five hundred bucks a month for heating. Of course if that's the case he could save a couple hundred bucks a month by installing a solar heating system and a two speed pump.
I agree with the electric companies on this point. If they dont need the electricity, why should they be forced to buy it? That will increase costs for non-solar customers as they end up footing the bill for the battery storage needed by solar customers. I think the proper way to do these installs is to have customers always have on site batteries which store the energy for their own homes use. Yes, its nice to sell back electricity to the grid, but that feels like a very hackish way to use 'solar'. It makes sense also. If you want to save money on your electricity, you need to make your own, so you draw less from the grid- Not make it for someone else when nobody wants it.
Does anyone know if the power company is required to buy all forms of electricity currently? Could you just setup thousands of solar panels in a field you own and demand money from the grid? Seems like a easy return on investment, depending on the cost of panels/equipment.