Comment by PaulHoule
7 months ago
Yeah, and people are talking about renewables as if the storage is free. Or people quote case 17 out of
https://www.eia.gov/analysis/studies/powerplants/capitalcost...
as if 1.5 hours of storage was going to cut it. I've been looking for a detailed analysis of what the generation + storage + transmission costs of a reliable renewable grid is that's less than 20 years old covering a whole year and I haven't seen one yet.
I haven't seen one either.
To be honest, I don't think anyone has any idea yet (other than crude upper bounds) because it depends a lot on things like how much demand response can help. Demand response doesn't have to mean "rolling blackouts"; it could mean "running the freezer during the day when electricity is free". Will people heat their houses in the winter with sand batteries? Will desiccant air conditioning pan out? Can nickel–iron batteries compete economically with BYD's gigafactories? What about sodium-ion? Nobody has any idea.
I was pleased to calculate recently that the EV transition, if it looks something like replacing each ICE vehicle with the BYD equivalent of a Tesla Model Y, would add several hours of distributed grid-scale storage, if car owners choose to sell it back to the grid. But that's still a far cry from what you need for a calm, cloudy week. Maybe HVDC will be the key, because it's never cloudy across all of China.
Sensible-heat seasonal thermal stores for domestic climate control (in some sense the most critical application) have been demonstrated to be economically feasible at the neighborhood scale. PCM or TCES could be an order of magnitude lower mass, but would the cost be low enough?