There's a lot more than the lovely chest fridge at
A heat pump with a 4-6 COP is nice, but a good solar heating system might have a COP of 50 or more. John Christopher's CSI building in cold, cloudy New Hampshire is heated with "98% solar power and 2% fan power." PE Norman Saunders calculates that some of his solar houses will only need "purchased heat" for a few hours every 35 years. No wood. No heat pumps.
The reflective solar heating system might lose lots of heat through windows at night and on cloudy days. A low-thermal mass sunspace with an insulated wall between the sunspace and the living space and warm air circulating between the two and no airflow at night might be a lot more efficient. The Barra system stores heat from sunspace hot air in ceiling thermal mass, with little heat loss at night. A slow ceiling fan and thermostat might bring warm air down from a low-e ceiling when a room is occupied.
As an alternative to a massy ceiling. Fin-tube pipes near the ceiling could both collect and distribute heat from a stratified storage tank, with the help of a ceiling fan. The tank might also have a $60 1"x300' pressurized PE pipe spiral near the top to make hot water for showers.
Nick