Re:China to supercharge uranium race with 150 new nuclear re...
by pfdietz on Wednesday November 10, 2021 @02:16PM
(#29179164)
> This assumes massive advances in battery tech to support seasonal and week-to-week weather changes.
This is bad engineering. One would not use batteries for that sort of long timescale storage, one would use something like hydrogen. The round trip efficiency is much lower, but with the much smaller number of charge/discharge cycles that doesn't matter. The effect of efficiency on the cost of storage scales inversely with the average storage time; it's important for diurnal storage, not important for seasonal storage. The energy capacity cost of hydrogen storage could be maybe $1/kWh of capacity.
For a timescale of a week, thermal storage is an option, with sand heated to 1200 C. Round trip efficiency would be 53%.
This is bad engineering. One would not use batteries for that sort of long timescale storage, one would use something like hydrogen. The round trip efficiency is much lower, but with the much smaller number of charge/discharge cycles that doesn't matter. The effect of efficiency on the cost of storage scales inversely with the average storage time; it's important for diurnal storage, not important for seasonal storage. The energy capacity cost of hydrogen storage could be maybe $1/kWh of capacity.
For a timescale of a week, thermal storage is an option, with sand heated to 1200 C. Round trip efficiency would be 53%.