Comment by WJW
3 days ago
Depending on how powerful your air conditioner is, it would rapidly start cooling down the building to a temperature which is too low to still be comfortable. You could maybe buffer this with more thermal mass, but then you are back in the game of storing energy and might as well just get extra batteries.
Many heat pumps already have a mechanism for deliberately wasting energy for defrosting the coils. I bet that the same hardware with a different control algorithm could be convinced to heat out the outdoors without much net change in indoor temperature. (The solution involving the smallest amount of extra hardware is to run the system in reverse periodically. There are other solutions.)
Whether the negative energy price is enough to balance wear on the system and potential noise is a different question.
Why not place the air conditioner next to a large electric space heater?