I'm building a new house and I'm based in Poland. I'm going with air heat-pump* + a simplest fireplace as a backup - not connected to central heating, no electronics. On top of that 10-20kW of solar and a place for batteries. I'll install them once they get cheaper. The house is 200m^2, so I'm hoping to pull only 200 kW/month from the grid and generate rest on my own.

Also, I've been wondering how much efficiency would I get if I could put some mirror and direct the light to the unit in the winter. It could help with defrosting as well.

*I was considering horizontal heat pump, but it's not worth it. It affects vegetation and future construction.