6. Electric Tank

The technology is tried and tested, and the tanks are cheap. Take the money you save and increase the size of your planned solar array. Tilt your (north) array string a little bit more towards the horizon to increase winter generation. Put your (300+L) electric tank on a timer so that it only comes on between, say 11:00 and 15:00. (Increasing solar self-consumption is better than any feed-in tariff that you're going to get nowadays.) Surplus power from your larger array can go to charging your EV or be sold back out to the grid.

There are fancy options, but you don't need fancy options.

Note: Any arguments about efficiency are moot when you generate your own power and have a regular surplus during the day.

Note 2: Heat pumps have noisy fans that can run for hours on end. (Solar) Electric tanks are completely silent. That also may matter to you.

6. Electric Tank

The technology is tried and tested, and the tanks are cheap. Take the money you save and increase the size of your planned solar array. Tilt your (north) array string a little bit more towards the horizon to increase winter generation. Put your (300+L) electric tank on a timer so that it only comes on between, say 11:00 and 15:00. (Increasing solar self-consumption is better than any feed-in tariff that you're going to get nowadays.) Surplus power from your larger array can go to charging your EV or be sold back out to the grid.

There are fancy options, but you don't need fancy options.

Note: Any arguments about efficiency are moot when you generate your own power and have a regular surplus during the day.

Note 2: Heat pumps have noisy fans that can run for hours on end. (Solar) Electric tanks are completely silent. That may also matter to you.