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points by ben_w 3 days ago | 0 comments
My guess is seasonal will be handled with flow batteries. A big tank and cheap-ish electrolyte, with the expense being in the electrodes sized for whatever max power is required. Tanks good for multiple cubic meters worth of liquid storage aren't exactly difficult to find, nor to place in a garden.

Then again, I'm basing this opinion on a recent-ish video from NightHawkInLight: https://www.youtube.com/watch?v=eq7fR9ISuCw

[–] pfdietz 3 days ago
Flow batteries might be ok for a week or so, but their market window has been shrinking as Li-ion has gotten cheaper.

The technology I'm most excited about is ultra low capex thermal, as being done by Standard Thermal. Capital cost per unit of energy storage capacity as low as $0.10/kWh(th), so it can work with seasonal storage and just a few tens of charge/discharge cycles over its lifespan.

Standard Thermal has raised $11M and is building in Germany, where they say they can deliver 365/7/24 solar resistive heat (400 C or perhaps 600 C) for half the cost of heat from burning natural gas there.

[–] cyberax 3 days ago
Flow batteries keep coming up again and again, but they just don't work well in practice. The power density of electrodes is too low to be practical, and this is a fundamental problem.

A regular 18650 cell has about 0.1 square meters of electrode surface. And you have thousands of these cells in a car battery, resulting in literal football fields of electrode area.

[–] TheCoelacanth 2 days ago
Seasonal will be handled with wind-power (tends to produce more power when solar is producing less), building extra (power being too cheap in the summer is a great problem to have) and long-distance power transmission (plenty of sun in the southern US or southern Spain even in the winter).
[–] ben_w 2 days ago
Those all help, to be sure. Personally, in my "if I was king of the world" fantasies, I'd make a global power grid. Aluminium production is actually high enough already for genuinely antipodal connectivity at 1 Ω, though it could also be grown fairly easily if this needed to be done faster than a timescale of decades or it turns out 1 Ω isn't low enough resistance. Main limit is global geopolitical issues, hence "if I was king of the world".
[–] pfdietz 2 days ago
Wind certainly helps, but there's a question of what will happen to the relative cost of wind and solar in the future. Solar seems to have a steeper experience curve.