If his winter heating need is that large he may live in an area where solar does not produce that much electricity during winter. I myself live in an area that has 0 (yes zero) sunlight for one winter month because of the polar night and just 1-4 hours of very low intensity sunlight for the rest of the 5 month long winter. In summer when we have midnight sun, literally 24 hour sunlight, the electricity is almost free so whatever the solar panel produces then is near useless. Also you simply don’t use that much in that season. For me at least it’s not really a worthwhile investment.

I did go back to burning wood. Per watt of heat it’s roughly ⅓ of the price where I live and with the specific set up I have. However the largest drawback of wood is that it entails a lot of manual work. First I have to spend a dozen hours carrying wood into the basement during autumn. Then during winter I have to go down 2-3 times a day to feed the furnace. However to me it’s worth it. It’s a comfy ritual that saves 5-20 euros every single day during winter depending on what the electricity price is that day.

The Qing emperor’s didn’t have multiple wives. They had one wife who was the empress. The rest were mere concubines.