Regarding [1] - are you being sarcastic?

Is that a serious question?

Yes. The dominant (essentially only at the surface) source of heat on the planet is the Sun?

Of course it was sarcasm. I meant to highlight the major problem for using renewables for heating: you'll need most of the power when the least amount of daily solar insolation is available – in winter. This means you either need a lot of storage capacity, or a lot of transfer capacity from far away places, to cover several days of dunkelflaute [1]. This problem is solvable, but it's hard and expensive to solve in practice.

[1] https://en.wikipedia.org/wiki/Dunkelflaute

I couldn’t tell because many people make arguments (or imply) that it doesn’t matter with an apparently straight face all the time! Including large scale gov’t programs.

Including other comments on this exact thread where people did exactly that.

You don't actually need your heat pump 24x7 even on those cold days, if you can run for 15 minutes one, 15 off that would make a big difference to the grid (your neighbor running the same schedule but opposite times) without making your house too cold. Managing the above is tricky though.

> You don't actually need your heat pump 24x7 even on those cold days, if you can run for 15 minutes one, 15 off that would make a big difference to the grid

That's already the case – the actual heat pump only runs intermittently, on demand. This happens quasi-randomly, so you automatically get some load balancing across a city.

The problem is that this is intra-day load balancing, which doesn't help one bit if there are several days of low supply (windless winter days).

What your thermostat does is not synchronized with your neighbors, so the peak load is not managed.

It also isn't synced to supply, instead most people have it set to different temperatures based on when they are home. It would be better to cool or heat the house based on supply. You want the house between 21 and 24c, you don't care when the system is on.