Air source heat pumps are a very bad news for the grid when they aren’t backed up by natural gas pre-heaters for when the air temperature is below 40 degrees.

That’s why Albany’s All Electric Skyscraper in 2006 – One Commerce Plaza – added gas pre-heaters. The electric pre-heaters were burning megawatts of electricity when it got below 40 degrees, a common condition in Albany during the winter. Except for the gas pre heaters in extreme cold, the building is still all electric as it has been since the 1960s.

Ground source heat pumps don’t have this issue as if you are below the frost line in most of America, it never gets below 40 degrees. Heat pumps don’t require pre-heating when it’s above 40 degrees or so.