Comment by bluGill
9 hours ago
> The frequency itself is then provided by the rotational inertia of "spinning metal" power plants.
This might or might not be true. I used to live near a large plant that took HVDC from a power plant several states away and transformed it into AC. They used electronics to provide the grid frequency, not spinning metal. All the other local peak power generation was run in grid following mode.
Grid Forming Batteries are a thing - but since it's not free to implement of course such a provider would like to get paid, not give it away, whereas both a conventional thermal plant or a hydro plant unavoidably has spinning metal, their stability comes free with the electrical supply.
The risk vs reward isn't great. If you made your country's 10GW grid work with only batteries for 15 minutes to show it's possible, maybe you get one half page in a "Electricity Weekly" industry newspaper. But if anything goes wrong and ordinary people notice - now you're on TV News for a week.
I'm under the impression that most grid scale batteries are owned by the utility which in turn cares about this. And the rest are only going to be bought if a utility \ grid gives them a contract where again those who care will give better terms of they need it.
My home battery might participate without the above but in to small to matter.