[adwn]

> 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).

[bluGill]

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.