Careful of the municipal utility bait and switch! Here in Idaho they recently adjusted the net metering credit to greatly decrease the value of solar energy.
They waited until there was a lot of solar adoption in the state, and then pulled the rug on solar owners under the guise of “making sure everyone pays their fair share”
I wouldn't characterize that as a bait-and-switch, but as adjusting to economic reality. When solar is <1% of penetration, a solar kWh is basically just as valuable as any other kWh. When solar gets over 10% of penetration, a solar kWh is worth much less than any other kWh - when the sun is shining, energy is plentiful. By the time you get to ~25% solar penetration, energy is almost free on a sunny day at noon, and much of the value moves into storage, to move the solar energy from noontime to the evening.
Nonsense, until 100% of daytime generation is solar/wind every KW added still offsets generation from other sources. This myth is mostly perpetrated by the suppliers of power based on more expensive and more polluting sources who see the value of their investments slashed.
I wouldn't be so quick to dismiss timerol's point as nonsense.
I live in Belgium. I was doing some electrical work in my home recently. On the 29th of May, I noticed two out of three phases were close to 250V instead of the intended 230V. This is the limit where inverters of solar installations switch themselves of; it indicates more solar power was being produced than could be absorbed by the grid.
It turns out the day-ahead electricity market prices on that day were negative for 8 hours. As I noticed with my voltage meter, such price signals are trying to tell us something. Shielding market participants from those signals (e.g. by net metering) will cause real technical problems.
I already try to be part of the solution by charging my EV around solar noon, even tough I don't have solar panels. And I will switch to dynamic hourly pricing soon. But one person voluntarily acting on price signals is not going to be enough.
I already documented precisely this in another comment. Inverters switching off means that everything works exactly as designed. Negative prices are mostly on account of those producers that don't switch themselves off, such as nuclear power stations and baseline load providers that are too slow to adjust to demand or supply peaks.
With 50 panels on my property (a good 12.5 KW of generating capacity based on the nameplate power of one inverter and the peak capacity provided by the other) I probably am on the large size for a domestic installation. But you don't install solar power for peak capacity, you install it for average days and not so average days when you're going to need every Watt produced. And on those days (when power is scarce) you'll find that you are still consuming from the grid. That's the only issue with solar: when you need it most it isn't there. And so everybody gets to be happy: less CO2 emitted, fewer fossil fuel tonnage burned as if there is no tomorrow and some cash back for those that invested in solar. In the long run everybody wins, in the short term some parties may have to review their spreadsheets. But those traditional suppliers definitely aren't losing money, in fact they made out like bandits over the last year or two.
Oh, and as for the 'intended 230 V' -> grid voltage can be between 228 and 252 inclusive without violating the standard. Nominally it is 240 V, not 230 V. The way inverters inject power into the grid is by syncing to it and then leading the phases a bit to cause current to flow. The RMS voltage will rise as a consequence of that.
Did you catch the "Belgium" in my comment? Here in the EU, the grid voltage is targeting 230 volt (± 10%). (Either between the two phases in a two phase system, or between phase and neutral in 3 phase systems.)
Fair enough, but I've never seen it drop below 228 and I've never seen it go above 253 and 240 is the rough midpoint between the two. I suspect this was to accomodate the UK which did have nominal 240V so that all of Europe could be 'one standard' without the requirement for gear to have many different voltage selections. So now the only time you see 230 is when the sun isn't shining the rest of the day you're much closer to 240. Incidentally: this is also why a bunch of older appliances are at risk of burning out. If they were marginal when we were still nominally 220V then 230V was already pushing it and 253 V (still within EU tolerance, 230 x 1.1 is 253!) will definitely cause damage. Newer gear is more forgiving about this. Hence the spike in business at white goods stores during days with lots of sunshine...
Older appliances typically had a whole raft of supply voltages to choose from 100, 110, 115, 120, 200, 220, 240 and sometimes even 127 and 245 and I'm pretty sure I've seen even weirder ones (150, 185 iirc). Now it's just 120 or 240 for regular consumer gear. BTW, brownouts are more of a risk than overvoltage, with brownouts a powersupply that autoranges might accidentally pick the lower voltage and then when the brownout ends magic smoke comes out.
That's not how energy markets work. This is by design and whether or not you think it's fair isn't really all that important. Energy prices are determined by the most expensive source of the moment, not by the least expensive one.
That's fair, but it would have to shift quite a bit still to get to the point where the marginal source would be a different one. Typically this is to all of the producers benefit (including the solar ones) so they tend to keep those most expensive sources alive at all costs.
I am fully pro solar, but the duck curve is a real thing. Time value of money and time value of electricity. If there is nobody to consume that extra juice it is of limited utility.
Extra solar power that doesn't get consumed simply isn't metered at the source. That's a direct function of how the grid works, as long as everybody plays by the transport rules regarding minimum and maximum voltage overcapacity is dealt with by simply reducing the amount of production. I see this up close almost every day on the local grid here, you can tell by 1 pm or so that the local grid is saturated and after that inverters start dropping off one-by-one until the voltage has dropped sufficiently for them to come back online again after a cool-down period (typically about an hour).
There is not such thing as 'extra juice', all that happens is that some panels are not generating. After all, if there were 'extra juice' that would imply forced consumption or some kind of giant sink load to take excess power. Neither of these happen, it's financial until some lower bound and then it gets technical.
The lower the impedance of the local grid the more margin there is for such adjustments to take place, if you are on a high impedance subnet in an otherwise low impedance grid chances are that your inverter(s) will shut down well before the grid itself has maxed out.
What’s “free” about maintaining the equipment or the cost of the equipment over time? The people that invested in installing solar still need to pay off the cost in order to break even. I guess they can eat the cost knowing that they’re saving the planet by giving away power they paid to harvest to a power company to profit off of.
You're misreading my comment a bit. It's only "free" on a sunny day at noon, because of the massive oversupply. The panels will make money, but at times when supply is lower, like after 2pm range. This depends on time-of-year as well.
Solar prices have been falling rapidly, so the value of a kWh of energy generated via solar has also been falling in competitive power generation markets.
This only happens a very small fraction of the day, typically within an hour either side of solar noon. And if the voltage goes up too far inverters will typically back off either incrementally or by shutting down entirely.
Net metering takes this fully into account, since it’s a dollar-for-dollar trade. I’d electricity is cheap during a certain part of the day, what they pay you is cheap.
The whole "paying the fair share" is just propaganda from oil companies. I saw a great video about that recently which sums up the situation nicely. https://www.youtube.com/watch?v=dPfpa2KqYk0
I'm a fan of this guys channel, he does good work and is generally well informed and informative. This video was by far his worst ever. Yes, the groups supporting this stuff have questionable motives, but the fact is that the payment model for power needs to change under a "prosumer" paradigm. Disentangling grid connection fees and power fees just makes sense. And yes, it does reduce the incentive of putting rooftop solar, but that's because the incentive was artificially high. Being connected to the grid is a valuable service that should be paid for. We used to pay for that because the cost was baked into the price of power. Now that some people are, on net, not buying power, it needs to be disentangled. Infrastructure needs to be maintained, and that has costs that need to be paid even as we switch to a renewable future.
Imagine a situation where everyone has rooftop solar, enough that, under net metering, they pay no fees. What happens? The power company goes under and now you don't have a grid. Which every one of those solar users _still needs_. There is _value_ in being able to buy power when you want it and produce it when you don't, and that value should be paid for.
> Why is this important? Because the potential impact of net-metered solar on electricity prices doesn’t even become relevant until you reach higher levels of penetration, or roughly 10% and beyond.
I think what I said was in line with that video's conclusions, which seemed to be arguing for continued net metering in the eastern half of the country, and used CA as an example of when the current policy hits its limits.
Real time variable rates are needed. These would also incentivize all sorts of load shifting strategies, which are very economically advantageous, if the damned pricing system can allow them.
That's very common in Finland and I think in many other countries in Europe. People use their water heaters, charge cars, etc. during the night when it's basically free.
The old scheme was variable rates on a fixed schedule. I'm talking about more flexible variable rates that correspond to actual conditions (both supply and demand), adjusted at high cadence.
That also happened in CA but if you already had solar panels you continue with the same rate for a while. Doesn't seem right to switch it for those already installed.
Doesn't seem right to limit it at all, new or already installed. In fact they should be quadrupling down on incentives for solar considering climate change.
If what you care about is climate change, single home rooftop solar is a _terrible_ investment. It's dramatically harder and more expensive to install relative to large installations. For the same exact dollar, you get nearly twice the installed capacity with large scale installations vs. home scale.
Why not both? With rooftop, you further accelerate the growth of renewables, and you get the benefit of not being beholden to regulatory capture and corrupt central authorities when they decide to do something stupid with the central power supply, and you also build up resilience in the grid with less single points of failure.
I'm not against rooftop solar. My parents have, what was, at the time of installation, the largest residential install in the state of CA. But rooftop solar is not a good use of resources for fighting climate change, which is what I was responding to.
I don't follow. How does it not help in the fight against climate change? It may be less effecient than central power but it still reduces emissions compared to fossil fuels, and it's not a zero sum game as it does not take away capacity from central power.
There is a disconnect for sure here - I said I agree that it may be inferior efficiency-wise. I also said that, nevertheless, it's still far better than fossil fuels. Both statements are true, and are not contradictory. It moves the needle in a positive direction on climate change which was my original statement. I never said anything about it being the best possible of all solutions. If you want to be pedantic, not using any power at all, and going back to an agrarian lifestyle is more efficient that centralized solar.
Don't let perfect be the enemy of good. There's no way that our governments are going to put all possible resources into a centralized renewable grid, so we should also incentivize private individuals to invest while we are waiting for our politicians and power companies to get on board.
I mean, if you want to waste your money, fine. The question is whether encouraging residential PV is good policy. I don't think it is in most cases (maybe if it allows homes to be totally disconnected from the grid, saving the cost of running lines out to them?)
> Careful of the municipal utility bait and switch! Here in Idaho they recently adjusted the net metering credit to greatly decrease the value of solar energy.
As other have said, people taking the bait changed the economics, and that forced the switch. To be fair, it was foreseeable.
Here in Australia we have the worlds highest rooftop solar take up. Feed-in rates are plummeting like a stone. It's not hard to see why - most days when the sun is shining brightly, the wholesale price of electricity is negative. Look at SA here at midday (the picture will change tomorrow): https://aemo.com.au/energy-systems/electricity/national-elec...
We do have plans here that expose you to that wholesale price. If you export electricity when the price is negative, you pay the grid.
Ironically, at the same time this over supply is happening all states that mainly use coal have been hit by a price rise this month. I got mine today. In 22 days, the price of my electricity is going up 45%. That mainly caused by renewables (and particularly solar) making the old coal plants uneconomical. They used to be able to sell power 24 hours a day. Now since they can't ramp down quickly they have to pay the grid to export their excess power during the day. I don't know whether that's the cause, but right now we have gigawatt coal plants shutting down years earlier than they said they would five years ago. Which is how we get a 45% price rise.
So we are in this situation where feed-in tariffs are worth nothing, electricity prices are going through the roof, we are throwing away a ton of electricity we can't use during the day and solar installs are slowing down.
The solution is storage, of course. Batteries were hard to justify price wise a few days ago. But after this 45% price rise changed that. Again it's a double whammy, but in reverse this time. Remember during the day the price goes negative. That means the grid pays you to charge your battery. I would not be surprised if for a while, the return on a battery will be higher than installing solar panels.
Which means the next phase of the renewable change over has hit us with a vengeance in Australia. It's the invisible hand of the market finally directing investment where it's needed most I guess. It arrived a little late, and it's not so much a hand as a fist. We would have been better off building storage a few years ago. And again, that was foreseeable. Indeed it was foreseen by numerous published articles. But who reads learned engineering articles on future electricity tariffs? Not your average noob looking purchase roof-top solar apparent and if the people hawking solar panel installs read them, they didn't mention it.
So here we are. We wanted an energy transition. Now we've got one, ready or not.
They waited until there was a lot of solar adoption in the state, and then pulled the rug on solar owners under the guise of “making sure everyone pays their fair share”