Comment by phil21
4 months ago
Well, I certainly can’t make a couple weeks of battery storage pencil out vs. a fossil fuel generator at this point.
The math actually gets worse once you get into combined cycle natural gas at scale.
You I suppose could make an argument that load curtailment is cheaper than planning for the current grid reliability everyone has gotten used to over the past 50 years, but it would be a societal shift.
Seasonal energy storage is what is interesting to discuss, and of course is where that last 2% of grid reliability comes from. It’s also the most expensive part of running a grid. The first watts are basically free, the last are very expensive.
I’d love to be proven wrong within the next decade though! I just personally don’t see the battery storage price going down at the same rates it has been simply due to structural raw material input cost reasons - short of a breakthrough in chemistry. I think we are getting close to the maximum savings achieved by economies of scale with current technology.
You shouldn't need a couple weeks of battery storage - if you're in a sunny place. For example Las Vegas should be able to reach 97% uptime of constant energy supply (greater than your typical fossil fuel plants uptime) by building ~17 hours worth of storage and ~6x the amount of power needed in the nameplate capacity of the solar panels. Even a slight bit of curtailment, the kind already done on western grids, to reduce load when the weather calls for a bunch of clouds, or uncorrelated energy production (e.g. wind, which won't necessarily go down on the odd cloudy day, or for on-grid cases just transmission lines to solar somewhere else, or a backup generator), pushes that much further to 100%.
Seasonal energy storage is uninteresting, you just overbuild the energy production instead. This is already done for every existing type of energy production to account for seasonal variation in demand.
If batteries became cheap enough where you could do days instead of hours affordably it pushes this sort of calculus into less sunny places as well, and there's every reason to think that they will become that cheap (perhaps not cheap enough to make weeks reasonable though).
> Seasonal energy storage is uninteresting, you just overbuild the energy production instead. This is already done for every existing type of energy production to account for seasonal variation in demand.
It’s the only thing that is interesting, considering you just hand-wove that last 3% of reliability away with vague “backup generators” and “transmission lines to other places”. Both immensely expensive items if they are idle 97% of the time.
I’m not interested in the least about having my grid availability at 97% - in a cherry picked location ideal for solar.
I’m totally fine overbuilding nameplate capacity for my solar field - already plan to by about 8x due to where I live. Panels are cheap! At least that problem seems more or less solved.
The issue is I have no realistic means to store that energy for even days much less weeks when the sun doesn’t shine. A small wind turbine can help a bit, but doesn’t get rid of the need for a backup generator.
The same holds true at grid scale currently - which is both a more important topic and more interesting to discuss than some rich tech bro being able to brute force his off-grid solar+battery install.
Someone needs to back that last 3% with something like a combined cycle natural gas plant. That amount of capital investment sitting idle is exceedingly expensive. The only thing you are saving much money on vs. running it all-out is fuel costs - you still need to staff it.
A national grid sounds pretty neat, but would both be crazy expensive and is so politically untenable that I don’t expect to see it seriously even discussed in my lifetime. Just a small amount of time spent in the rural areas of the country made me realize how utterly impossible it would be due to NIMBY.
Again, to me at least that last 3% is where everyone hand-waves and makes it someone else’s problem. At some point though you run out of other people’s power.
I do wish we had not destroyed our nuclear industry into irrelevance, as 50 more years of experience and hands-on construction knowledge pushing that tech forward might have had us in a far different place today!
And fwiw I do hope I’m wrong. Perhaps energy storage gets to the point we can keep a fully reliable inexpensive grid for the common folks and industry to rely upon. I’ve certainly been wrong before!
You understand that fossil fuel and nuclear plants are typically less reliable (have a lower availability factor) than that right? Every form of power generation has downtime, and needs balancing with other types or accepting that downtime. Solar tradeoffs low mechanical complexity for higher environmental dependence, but ends up with similar (in fact less) downtime here under unfavorable assumptions (100% of energy coming from a single point source of solar, constant energy load not your typical lower energy from consumption energy at night, no ability to shed load with price signalling or curtailment).
The last 3% is left alone because it's the fair comparison to other energy sources... tilted in the direction of favoring the other energy sources.
> It’s the only thing that is interesting, considering you just hand-wove that last 3% of reliability
The 3% issue doesn't come from seasonal variation, it comes from short term weather patterns where you might have a week of heavy cloud cover. Seasonal variation is trivially solved by simply increasing the multiplier on nameplate capacity (and the 6x for Los Vegas includes that increase). It's always going to be easier to generate an extra 25% energy than to store 25% of your energy produced in summer and use it in winter.
> “backup generators” and “transmission lines to other places”. Both immensely expensive items if they are idle 97% of the time.
On the contrary both things that exist anyways. Every place that cares about consistent power already has backup generators for when nonsense happens like power poles being blown over. Transmission lines exist to allow sale of excess production. It's only at tiny scales where these things aren't pre-existing and at those tiny scales overbuilding solar and batteries even more is so much cheaper than the alternatives (like building redundant gas plants disconnected from the grid, or even just redundant diesel generators) that they win by a mile.
An understated win of the storage model here is that these generators don't have to be able to supply the entire load, they just have to be turned on in advance when the weather forecast says there might be a problem to slow the drain on the batteries.
PS. I don't know what country you're from, but it seems a bit crazy to me that you apparently used to have a nuclear industry but apparently don't have a national grid... If you have actual weeks where the sun doesn't shine and no grid... you aren't in a sunny place... so you can still brute force it of course but done efficiently a lower percentage of solar makes sense.
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