Geothermal heat pumps "store"... They pump heat into the ground in the summer for air conditioning and pump it back out in the winter for heating. You don't n

Geothermal heat pumps "store"... They pump heat into the ground in the summer for air conditioning and pump it back out in the winter for heating. You don't need to be "much", you need to ideally match the TCO of other fuels (or come close, if you care more about reducing fossil fuel use and CO2, which is arguably more important than TCO. People obsess about heating costs but then run out and buy $60,000 luxury cars to do an hour+ commute each day in.)