~30% of the NYC area is still probably running steam heat which just uses physics to get where it's needed. Depending on the system size a car battery and inve

~30% of the NYC area is still probably running steam heat which just uses physics to get where it's needed. Depending on the system size a car battery and inverter can run a forced hot water system for a pretty long time. Forced hot air is gonna be worse than that but the electricity to run the blower is still peanuts compared to a heat pump system.