Plus it is possible to "bank" heat -- passive solar systems do it all the time, and I seem to remember seeing a plan for a system that used a heat pump to transfer energy to what amounted to an insulated box of rocks, from which heat could be extracted later.
-- Bob
---------
Then the horns kicked in...
...and my shoes began to squeak.
-- Bob
---------
Then the horns kicked in...
...and my shoes began to squeak.