Heat source selection based on carbon intensity

Hi all,

I’m just getting up and running on HA.

The main reason I’m going to HA is because I live in an area of huge temperature swings AND huge fluctuations in electrical grid carbon intensity. I have a gas furnace and a heat pump.

I’ve written some logic that uses API calls to OpenWeather and ElectricityMaps to calculate the optimal heat source from an environmental perspective. I have an Ecobee connected to HA via Homekit, but have discovered that I don’t have access to aux heat control.

I have separately built a prototype thermostat with a bunch of solid state relays, but am an incompetent coder and worse at hardware. If my ecobee can’t be convinced to do what I want, then I’d rather buy a HA friendly thermostat that does what I want.

So the questions are:

  1. Is there a way to control aux heat with an ecobee since API access was terminated.
  2. Is there a better thermostat to use in place of my ecobee.
  3. How’d y’all get so smart? This stuff is hard.

Thanks all!