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Comment by kilroy123 | Hacker News Reader

Just over build the solar. Build out solar so demand in winter is met.

Use the excess power in summer for some kind of industrial use.

This can lead to a solution, but at high latitude it becomes infeasibly expensive. Insolation varies too much from summer to winter. Low round trip efficiency long term storage becomes much cheaper than doing (just) this.

This assumes prices for the solar panels and batteries continue to fall as this build-out happens. I don't think it should or could happen in a single year, but slowly over the next 5-10 years.

Syngas (infinitely better than hydrogen, which was always a stupid idea), or huge-scale Carnot batteries (the square-cube law is your friend) would do the trick nicely in both cases.

Syngas has the problem of where do you get the carbon. With hydrogen, the exhaust (water) just gets released to the atmosphere. Syngas would require capturing and storing the CO2 of combustion for reuse in making more syngas, which adds to the cost.

But yes, resistively heated ultra low capex thermal storage ("hot dirt") is very attractive.

You would have to overbuild by a factor of 20 at least. Not at all practical or economical.

Citation? We get 25 units in the sun and 5 in heavy rains.

I'm in the UK. I covered my whole roof with 6.5kW of panels (it's pretty ideal south facing etc.)

I just checked our stats. Average consumption 16kWh/day. Sunny summer day we get 30-40kWh. Sunny winter day 10-20kWh. Cloudy winter day it's 0.5-2kWh.

Also that's without a heat pump... Which you mainly use in the winter.

And without an electric car but I doubt they're as big of an issue because you can charge them from cheap overnight power anyway.

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