If we burn 1000 watts of electricity in any electric resistant heater ("space heaters", electric convection heater, or electric fan heater), we will get 3,410 BTUs of heat for the electricity we've paid for. We get all the heat out of the electricity we've paid for, so our efficiency is considered to be 1, or 100%.
Now, if we burn 1000 watts of electricity with a geothermal heat pump, we get about 4 times the heat, or 13,640 BTUs. We burn (and pay for) one unit of electricity and transfer 3 units (free) of heat. We get 4 units of heat for the price of 1! This means our efficiency rating (COP: coefficient of performance) is 4, or 400 percent.
Geothermal Heat Pump efficiency is much greater than that of electric resistance heat!