100 gallons of gas is saved
It depends on the power rating. A typical nuclear power plant might be rated at 1100 megawatts, so that would be 1100 megawatt-hours in one hour. To translate that into SI units, one watt is one...
As much as they use
it depends on the r-value of the insulation and the area or temperature range of the climate it is to be installed
How much does earth rotate in one hour