this post was submitted on 22 Apr 2024
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I’m not familiar with how power grids work, is an excess of power bad for the grid if it isn’t used?
No. They constantly monitor it and keep it in line. The power grid itself is totally fine. Completely.
The only "problem" is they cannot easily turn on or off huge old power plants, so if the sun is blazing, they might have to direct excess old generation power to batteries or other grids.
The only "problem" is the power companies don't get to charge much for simply managing the grid. They charge mostly for power generation, so it ends up costing them money. If they were simply a government paid service, they wouldn't have to care what so ever which direction power is flowing as long as it has somewhere to go.
The main power company in CA (PG&E) has built tons of other things into the bills aside from power generation, so I expect my bill (which has gone up 300% since 2018) to continue to climb despite this.
my utility charges $25 a month just to be hooked up. then there's taxes and some community bullshit fees on top of the actual electricity usage. so even though my usage has dropped quite a bit over the years, and the base rate hasn't really gone up that much (about 10-12% total, over two decades).. my bill is still more than double what it used to be.
Seriously, i found an old bill from a decade ago, it was like $54 for my 1 BR apartment. It’s now usually over triple that…
PG&E charges me more to deliver power ($0.18/kWh) than it does to generate ($0.12/kWh) that power. That’s f’ed up.
They keep it in line by curtailing or switching off generation. The generator typically still gets paid as if it were generating whatever it has available, which is perhaps an issue, but the total generation is reduced to meet the demand.
This is why there is negative pricing, it's cheaper to sell electricity in the negative than to pay a generator to be offline.
They can't direct excess generation to batteries if the batteries aren't there yet. They're being installed, but the overall capacity is still relatively low. Transferring it to other grids also has limits, and in particular if there's an excess of solar in one region the neighbouring regions also probably have an excess, so there really is no other option but to curtail.
Jeeze it almost seems like the 21st century might take some sort of smart grid, and having a bunch of big dumb plants that cannot be turned on and off without great expense should be a relic of the past!
There is a cost to that. Everyone complains about that.
That's why for example China are building new coal plants. The new ones turn on and off quicker.
"Batteries" don't need to be what we commonly think of as storing electricity. They can very much be a different way of storing energy instead. For instance, pumping water up to a tower (or upstream), or splitting water into hydrogen + oxygen (for consumption/combustion later)
Yes I'm aware of water storage, and even quite fond of it, but it's very dependent on geography (as you need a very large body of water so you can't really just use a water tower) and also incredibly expensive. There are generally more effective and profitable uses for land.
Meanwhile BESS is tiny, something like 30MW per acre.
Storing energy as hydrogen is a fool's errand, in fact many of the new use cases for hydrogen are snake oil touted by people looking to sell more hydrogen. Even ignoring the fact that hydrogen leaks through and embrittles any container it's stored in (or that it explodes violently), converting hydrogen to electricity only leaves you about 70% of the energy you put in.
Kind of, yeah. But excess solar can be turned off almost instantly so it isn't like it's an impossible problem.
Sorry for asking all these questions, but how do you turn off solar? Doesn’t it keep generating while there’s sunlight?
If it's turned off, it's like a battery that isn't connected to anything. You have a voltage across the positive and negative terminals, but power can't actually flow unless there's somewhere for it to go.
Just disconnect the panel.
Yeah, various power generation techniques (e.g., big industrial power plants) do not want to run without a load. And switching them off temporarily isn't really feasible (shutting them for good would ultimately be nice, but that's another topic...).
And you can't just "dump" huge amounts of excess of power
it needs to go somewhere.
Tesla coils?