[Tuna-Fish]

The technologies I like provide solutions to the hard problems.

In Finland, the coldest weather is experienced when, during winter months, there is a persistent anticyclone parked overhead. Those can cover the entirety of the country, and inside them there is negligible wind. For example, on 8th of December it was -20°C, and the average output of wind power (nominal installed capacity ~2800MW) over the day was 330MW. The average output of grid-connected solar was <1MW (It's December in Finland, what did you expect?).

Anticyclones can remain in place overhead for weeks. The value often used to calculate the cost of renewable+storage is 3h. This is a reasonable value for California, where solar production correlates well with use. If you built the grid in Finland based on that, we would just die when it gets cold.

There are no renewables that work well in Finland. Water power is fully built out. Solar only produces power when we don't need it. Wind reliably does not provide power when we need it. Compared to renewable with enough storage, even with all it's overruns, OL3 is remarkably cheap.

[fulafel]

But how much of the heating is, or needs to be, electric?

Many current heating fuels are fossil and not great either, but they can be replaced with renewable fuels which solves storage vs renewable-produced electricity.

[Tuna-Fish]

The most common heating system in new separate homes are heat pumps. They can function as air conditioners when it's hot and heaters when it's cold.

[fulafel]

That does seem to head for electricity based heating. But a web search lead to some (admittedly 6 yrs old) graphs that have electricity being in in 3rd place after fuel based heating solutions by energy use: https://www.stat.fi/til/asen/2014/asen_2014_2015-11-20_tie_0... - and hopefully those new houses are better insulated and use proportionally much less energy than the average housing stock, eg passive houses.