The excess solar power is thrown away, raising prices. Due to a change in state law, homeowners, who had received retail prices for selling their excess solar power to the grid, now will be paid wholesale prices, which in some cases approach zero.
[pdf] Battery storage prices have gone down a lot since 2010. In 2025, they are about $200–$400 per kWh. This is because of new lithium battery chemistries. Different places have different energy storage costs. China’s average is $101 per kWh. The US average is $236 per kWh.
[pdf] The average price of lithium-ion battery packs is $152/kWh, reflecting a 7% increase since 2021. Energy storage system costs for four-hour duration systems exceed $300/kWh for the first time since 2017.
[pdf] A single CAES plant can store 100+ MWh – enough to power 10,000 homes for 10 hours – at $150-$200/kWh, significantly below many battery alternatives. China's Zhangjiakou CAES facility (2023) operates at $160/kWh, leveraging abandoned salt caverns for air storage.
[pdf] According to market data, the charge per rectangular foot of a container domestic commonly stages from $150 to $350 per rectangular foot, comparable to prefabricated houses but normally decrease than normal modular homes.
[pdf] This enables 20-foot containerized systems storing 500-800kWh to operate at $0.18-$0.25/kWh – now cheaper than diesel generators in most regions requiring fuel transportation.
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