I'll also have solar + battery. Should be able to run the furnace & fan but not the heat pump (too many kW/h) during a power outage and thus heating with gas. It'll run off the heat pump for 90-95% of the year, only using gas on the coldest days, or during an outage. To go full heat pump for 100% of the year you need to seriously upsize the heat pump(s) and you wouldn't have performance during an outage.
I'll also have solar + battery. Should be able to run the furnace & fan but not the heat pump (too many kW/h) during a power outage and thus heating with gas. It'll run off the heat pump for 90-95% of the year, only using gas on the coldest days, or during an outage. To go full heat pump for 100% of the year you need to seriously upsize the heat pump(s) and you wouldn't have performance during an outage.