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Utilities Battle Homeowners Over Solar Power
HughPickens.com writes Diane Cardwell reports in the NYT that many utilities are trying desperately to stem the rise of solar power, either by reducing incentives, adding steep fees or effectively pushing home solar companies out of the market. The economic threat has electric companies on edge. Over all, demand for electricity is softening while home solar is rapidly spreading across the country. There are now about 600,000 installed systems, and the number is expected to reach 3.3 million by 2020, according to the Solar Energy Industries Association. In Hawaii, the current battle began in 2013, when Hawaiian Electric started barring installations of residential solar systems in certain areas. It was an abrupt move — a panicked one, critics say — made after the utility became alarmed by the technical and financial challenges of all those homes suddenly making their own electricity. "Hawaii is a postcard from the future," says Adam Browning, executive director of Vote Solar, a policy and advocacy group based in California.
But utilities say that solar-generated electricity flowing out of houses and into a power grid designed to carry it in the other direction has caused unanticipated voltage fluctuations that can overload circuits, burn lines and lead to brownouts or blackouts. "At every different moment, we have to make sure that the amount of power we generate is equal to the amount of energy being used, and if we don't keep that balance things go unstable," says Colton Ching, vice president for energy delivery at Hawaiian Electric, pointing to the illuminated graphs and diagrams tracking energy production from wind and solar farms, as well as coal-fueled generators in the utility's main control room. But the rooftop systems are "essentially invisible to us," says Ching, "because they sit behind a customer's meter and we don't have a means to directly measure them." The utility wants to cut roughly in half the amount it pays customers for solar electricity they send back to the grid. "Hawaii's case is not isolated," says Massoud Amin. "When we push year-on-year 30 to 40 percent growth in this market, with the number of installations doubling, quickly — every two years or so — there's going to be problems."
But utilities say that solar-generated electricity flowing out of houses and into a power grid designed to carry it in the other direction has caused unanticipated voltage fluctuations that can overload circuits, burn lines and lead to brownouts or blackouts. "At every different moment, we have to make sure that the amount of power we generate is equal to the amount of energy being used, and if we don't keep that balance things go unstable," says Colton Ching, vice president for energy delivery at Hawaiian Electric, pointing to the illuminated graphs and diagrams tracking energy production from wind and solar farms, as well as coal-fueled generators in the utility's main control room. But the rooftop systems are "essentially invisible to us," says Ching, "because they sit behind a customer's meter and we don't have a means to directly measure them." The utility wants to cut roughly in half the amount it pays customers for solar electricity they send back to the grid. "Hawaii's case is not isolated," says Massoud Amin. "When we push year-on-year 30 to 40 percent growth in this market, with the number of installations doubling, quickly — every two years or so — there's going to be problems."
The complaints that the rooftop systems are invisible to the power companies "because they sit behind a customer's meter and we don't have a means to directly measure them" can be addressed pretty easily with updated electric meters.
The power companies are all moving towards "smart meter" technologies anyway. Why not make sure they've put one in that can monitor the output of a PV solar (or even a wind turbine) installation while they're at it?
When I had my solar system installed, the power company had to switch out my meter. And even though we're one of the last remaining areas around here that doesn't yet use smart meters, they still upgraded me to a bi-directional meter so my power generation vs. usage can be tracked. So they're spending $'s on labor and hardware to mess with your meter each time a new solar system is put in. It's their short-sightedness if they don't put more useful equipment in place while they're doing that anyway!
And when it comes to solar, I think the output is fairly predictable too. The only real "fluctuations" you get with the output are based on the day's weather conditions. If you compare my panels to my friend who lives on the other side of town and has a PV solar installation, our daily power generation numbers are within 2-3KWh of each other, and the hourly rates on a graph look almost identical. The power company receives and has to sign off on a registration form stating you've installed a small power generation system and they're made aware of its exact size/maximum output at that time. So even with NO other metering capability, they'd be able to predict that in a certain part of the circuit, they now have someone who will add, at most, a specific amount of power back to the lines between the hours of 10AM and 2PM (when the panels produce the most power). It seems like this is data they should be able to work with.
There's something to this claim. The power electric companies traditionally have control over all inputs to the system. Home solar changes that.
Unfortunately, the power company is still expected to make sure that the power comes in at the right voltage and frequency. And with control on only part of the inputs, that's a lot harder. The fewer inputs they control, the harder...
Theoretically, you can design a control system that'll handle the problem. But, so far, noone has bothered to, because noone's had a need to. As solar becomes more common that'll change, and the problems will go away.
One part of the problem is NOT going to go away however - they have to pay to maintain the lines. Right now, that cost if covered by your electric bills. As the amount of electricity you draw from their generators goes down, they're going to reach the point of needing to charge you a flat fee just for the connection to the power lines, plus the usual fees for actually using their electricity.
"I do not agree with what you say, but I will defend to the death your right to say it"
Its not just frequency and voltage, there is phase and power factor, harmonics etc. Grid tie inverters are not simple pieces of equipment by any means - they try to synchronize and follow the grid power delivery by following grid input AC waveform at the point of connection, which is a limited bit of information and may not be fully in sync with macro-scale grid need at any given moment.
For a perfectly synched network you would have to have atomic clocks and low latency radio link network with each point of generation, that's obviously not going to happen, so hacks, power factor correction systems, extra reactive loads etc are and will have to be implemented.
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EE working for a utility here, and I agree with all of this. The utility I work for, and a lot of others, don't even generate any power, we just do transmission and distribution, i.e. "poles and wires". Solar still causes us headaches. Don't get me wrong, I love solar, and I want reduced fossil-fuel usage, but the issue really is more nuanced than the public perception of "the utility just doesn't want us making our own power so they can keep charging us money".
Most people seem to operate under the assumption that power distribution is a network, where it flows in any direction. On the transmission side, yes, this is true. For distribution, it's generally false, except in large cities. More common are radial feeds, where several circuits, also called feeders, come out of the substation, each one typically having multiple branches and serving a certain area. Think of it like an artery system. The main trunk of the feeder has larger size wires that can handle more current, the branches have smaller sizes, etc. It's designed for power flowing from the substation to the customers, and not vice versa. There are a number of issues that arise when this expectation is violated. As a few examples:
If the homeowner at the end of the branch puts in a large solar installation, the wires and distribution equipment may not be sized to handle the power he's producing.
The variability of generation and inability to measure it is definitely an obstacle. Let's say there's an area with 20MW of load, and 15MW is being provided by solar. The solar output is unpredictable, but to the utility, who probably only has real time metering at the substation, it just looks like 5MW of load, so they don't know that when the sun goes down or a storm passes through they're going to see a major load increase.
It's a safety issue. The utility does not, and absolutely never will, assume that a customer has a properly functioning transfer switch that prevents backfeed during outages, which can be hazardous to both linemen working to restore power. There are certainly safety precautions that linemen can take, but it's still a danger.
On the billing side, the utility still needs to maintain equipment to provide whatever class of service the homeowner has. They need to be able to provide, for example, 400 amps, even if the homeowner gets solar and winds up having a bill of $0 from the utility. The O&M costs for such customers wind up being effectively subsidized by people who don't have solar.
I like solar, and I'm not afraid of it putting me out of a job, at least in my lifetime. I think when battery technology is more mature, it could help alleviate a number of issues that currently exist. But the public perception that its conspiracy by big bad utility is just trying to stifle competition is untrue. I'm not going to say that anticompetitiveness could never be the motivation for a utility to fight the proliferation of solar, but from an engineer's perspective, there are real obstacles that exist that many people don't realize or appreciate.
There are already strict requirements that must be met in order to connect a solar system to the grid. The devices that do this have all sorts of requirements regarding what the power must look like regarding conditioning and interesting things like disconnection should power drop in order to prevent energizing an electrical line that a worker thinks is dead because he doesn't expect you to push power. Meters that "run backwards" are also used with grid-tie connections already.
As it stands today in our existing system if an electric producer has excess they sell it to OTHER grids tied to their system, it doesn't simply go to waste. On an island like Hawaii that may not be possible but on the mainland it certainly is and those connections also stretch into other countries like Canada.
In short - most all of your assumptions about how power is just being thrown willy-nilly onto the grid are incorrect and already accounted for. If you think an electric company is going to allow you to (legally) connect without having passed those standards you haven't done your research. Look up Grid-tie to learn more.
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Why don't you ask them how much they pay per kwh while you are at it? (hint: it's around 3x the US average.) If you ask most americans they will not be in favor of paying 3x more for electricity just so the environmentalists can sleep at night.
But germans on average just use a tenth of the power an american uses, so bottom line we pay less than you.
My yearly bill is like 650EURO for electricity and roughly the same for gas.
Cost free eBook I read (by iBook/Kobo/Amazon/ObookO/Gutenberg etc.): "The Green Odyssey" by Philip Jose Farmer.
Coordinating the power grid needs information, today the information carried for proper coordination ( AC waveform detecion by grid inverter ) is not sufficient to make things work at large scale.
Whether you transmit the coordination signals ( i.e. extra bits of information ) in-band ( over powerline, superimposed on the AC wave ) or out of band on a separate carrier is the question of implementation. Both in-band and out of band would have their upsides and downsides.
Fact of the matter is that todays grid is not built for that.
Simple case, assume there is a dozen or so high power solar installations in my neighborhood, delivering most of the peak power output. The requirement for grid-tie inverters is matching the phase within 1% of the 50/60hz waveform read at the connection point. The question is, _whose_ waveform is mine really following ? Is it the neighbors ? Which one is his following ? How does the error propagate and does it multiply ? That is the gist of the coordination problem.
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In an unregulated market the power line company charges a flat government regulated fee to carry the power and maintain the lines. If the line company needs to adjust the fee they must ask for a rate adjustment. The line company at no time owns any electricity on the lines. The electric providers purchase electricity from generation utilities and contract with the line company to deliver the power to the consumer. If power goes out you call the line company for service but for billing issues you call the electric provider.
In a regulated market the power company is generator, line carrier, and electric provider. They can purchase extra power if they need it from third parties but it is tightly regulated.
Historically incentives for home electric generation have guaranteed a certain price minimum for anything sent to the grid. This works in a regulated market because the price is regulated but it doesn't sit well in an unregulated market because the price may be significantly more than the current market rate. Of course if you made it fairer many homeowners would cry foul even though it wouldn't be. But at some point that decision must be made and no politician wants to be the one to take something away from his constituents.
"A person is smart. People are dumb, panicky dangerous animals and you know it." - K
Besides, unless I'm misremembering my basic electronics, having extra power available is usually not a problem unless there is someone to consume it (*). I can hook up one side of a 110 volt outlet to a piece of aluminum foil, and until someone is stupid enough to touch it, it won't burn up. Overloads are caused by demand exceeding the available supply as it passes through some resistance (the wiring, for example).
You've got most of the right answers in there, but a little mixed up. The aluminium foil survives because it has low resistance, so little power is delivered over it. Electrical power is distributed across a circuit in proportion to resistance : P = I^2 * R. Low-resistance components (eg wires, and your foil is just a flat wire) are therefore less susceptible to oversupply. But put more power into the system, and more power will be delivered to all components, and some of them will fail and catch fire. Don't believe me? Get a 3V filament bulb and connect a 12V battery to it -- it will pop because too much power is delivered across the resistive filament.
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Household inverters will dump power into the grid as long as the grid is being maintained within some tolerance of voltage and frequency. This tolerance is quite wide, because otherwise inverters wouldn't work a lot of the time.
But the utility company would ideally like to be able to control the grid to whatever tolerance makes sense under current conditions, and this problem is not simplified by random (from its perspective) energy sources dotted around.
Also, the utility company has to maintain generation for the base load, and when a cloud greatly reduces the solar it has no control over, it has to quickly ramp generation up and then back down when the cloud goes away.
> By whom?
By all levels of government.
> Where's the budget item in the state/local/federal budget?
Right here:
http://www.eia.gov/analysis/requests/subsidy/
It's about $30 billion a year in direct subsidies. This does not include outside R&D, like the share of nuke development that happens as a side-effect of weapons programs (which has very recently dropped to just about zero now that MOX is largely run out). It excludes more wishy-washy issues like nuke liability insurance issues, or the more nebulous concepts like funding the Navy to keep the sea lanes open. This is pure, direct subsidies.
> Stop repeating paranoid memes.
Stop repeating BS that ten seconds of google will prove to be blatantly false.