Most of Polands heating is probably not electric. But it’s not unreasonable to store months worth of power, many countries have gas reserves in that ballpark. You just have to replace natural gas with a synthetic fuel.
That's just not true, unless you mean resource reserves. Taiwan has the largest NG strategic reserve I know of (11 days) and the US has the largest petroleum reserve in the world at 19 days: https://en.wikipedia.org/wiki/Strategic_Petroleum_Reserve_(U...
Resource reserves are unextracted and not replenished. They are not the same as storage.
This quotes Poland as having 89 days' worth of gas consumption with storage full, Hungary at 133 and Germany at 108. These are actual storage reserves, not untapped resources, at least for Poland.
>You just have to replace natural gas with a synthetic fuel.
The word "just" is doing a lot of heavy lifting there. For heating, by far the most sensible solution is to use summer PV to heat up a bunch of sand/rock wrapped in a ton of insulation, then use the stored heat in winter.
Resource reserves are unextracted and not replenished. They are not the same as storage.