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0 pointsPaulDavisThe1st3y ago0 comments

I live in New Mexico with a 6.7kW array. My house is heated with air source heat pumps. In the summer, we generate 3x the electricity we need. In the winter, we generate 1/3x of the electricity we need. Last year we generated 91% of all our electricity, the year before 93%.

We would need a gigantic store for heating our house, because for 4-5 months a year, we are generating less electricity than we need. Something on the order of 15MW of storage.

We could certainly our home's thermal efficiency, though this would be complex. We could also add more panels, but then we'd be overproducing by even more during the summer.

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solraph3y ago· 1 in thread

15MWh of storage seems very high? I appreciate I don't know your raw numbers of production and consumption, but don't you still produce some power during the winter? ie; you would only need to cover your shortfall.

For context, I live in the cloudy-ish south of Australia, and have similar problems with our solar power in winter. However, we still produce reasonable amounts of power through the day, and our total winter shortfall is only about 500 kwh, once offset against the daily production.

So for us, 500kwh -> 2080.8 MJ -> 462.4 litres of storage required (assuming 4.5 MJ / litre and ignoring round trip losses), which seems an entirely reasonable for local storage, safety aspects not withstanding.

PaulDavisThe1stOP3y ago

Our problem is not the shortfall in the winter generative capacity (sure, it drops a bit, but is still not far from 1MW/month). The problem is the increased load required for heating. I figure we need about 3MW/month for heat, for maybe 4-5 months, but you're right, the storage would only need to be 8-10MW, not 15MW since we'd still generate about 1MW anyway.

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