this post was submitted on 31 Aug 2026
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Sticking coal power generation on your roof, are ye?
From a power-generated-per-area perspective, PV is about 500x less dense than a modern gas-fired combined cycle.
Why does that matter? Solar can go where coal can't.
Put PV above a parking lot, you're not using that land for anything else useful anyway.
Lotta places it can go. Doesn't matter if it takes up more space.
Coal and gas plants can only go in specific spots. Need a water supply, needs logistics, needs a clear zone to vent. So it needs more space than a trivial accounting would indicate.
Solar can go in more diverse locations, absolutely. Especially advantageous because solar can be installed right on top of the buildings that need electricity. Lowers dependence on already-overloaded transmission lines.
Just from a utility perspective, it’s a lot simpler, easier to buy a plot of industrial zoned land, and stick a combined cycle on it. This is enough to power an entire medium city, 24/7.
Compared to logistically working with a massive number of private property owners to install solar on their property. And the result of all that work is enough to power the same city from 7 in the morning to 7 at night.
From a utility perspective, you may be right. Given the existence of an already-extant fossil fuel distribution infrastructure, I could see it being simpler.
But that said, the "amount of space used" isn't a great metric to compare the two, since the space used by solar is very different and can overlap with space used for other things.
Getting away from utilities, solar is something that individual people can install on their properties to electrify their own little baby power grid, feeding back to the wider grid or not. This will effect the demand curve in the aggregate, leaving utilities to cover the difference somehow. With load dropping to zero or near-zero during sunlight hours, and increasing in the off-peak and winter hours, they have to consider options to balance the grid that aren't appropriate for fossil fuel plants.
The niche that gas peaker plants fill is rapidly going away as battery technology improves. I think the calculus, in ten or so years, is going to be that it'll be "a lot simpler, easier to buy a plot of industrial zoned land, and stick a" battery farm on it to harvest surplus power during the daylight/windy hours and discharge it at other times.
I expect that demand for gas is going to drop precipitously in that situation, meaning that the whole fossil fuel distribution network may struggle, and prices will go up, further motivating distributed generation. And utilities are going to want to prepare for that earlier rather than later.
Agreed, energy density isn’t really very relevant from a grid perspective; space is pretty abundant when you’re talking about an entire grid region.
I was definitely hinting at the dispatch-ability of PV in my other comments, but you totally have the idea.
And it’s going to be batteries totally. At the publicly owned power utility I work at, I actually was in the energy storage technology group for a small stint. Whole purpose of the group was just running feasibility analyses on installing utility-scale batteries.
The core issue is batteries at scale are a completely infant technology. We had proposals that were literally straight out of graduate research. That’s great and all for the technology development, but my company only cares about reliability, dispatch-ability, and competitive rates. We’re not interested in prototypes.
I’d keep a close eye on molten salt batteries and flow batteries. I think those are the most developed. Especially flow batteries, companies like Sumitomo are making pretty big progress in Japan, and starting to move over to the US.
But again, issue is scale. A useful battery for a medium-sized utility is something like 50MW at 4 hours duration (equivalent to something like a peaker unit, though not all that useful for nighttime baseload). And this battery would be something in the range of like $250M. And a comparable gas peaker unit, about $80M, and that unit can run 24/7.
So the economics at utility scale are getting there, but we’re not there yet.
I do look forward to a 99% solar and battery grid though. With that 1% filled by emergency natural gas.
Are you counting the space taken up by the gas wells, transportation infrastructure, and storage facilities?