On average in 2019, it took an average of …
10,551 BTU or 3.1 kW of coal or 7,732 BTU or 2.3 kW of natural gas to produce 1 kilowatt of electricity, which is equal to 3,412 BTU.
With fossil generation, it takes quite a bit more kWh of the fossil fuel burned to turn into usable electricity. It took roughly 4.65 kWh worth of coal to make the 1.5 kWh of electricity, as it fossil fuels have significant losses due to the inefficiency in converting coal or oil into electricity.
How much does your 120 volt plug-in electric heater in your house use when it’s on? It doesn’t really matter whether it’s a $12 Walmart heater fan, or a $300 radiant heater in a fancy wood cabinet. All are same energy efficiency – when you apply resistance to electricity, 100% becomes heat, including the heat produced by the fan coils or indicator lights.
All 120-volt heaters are 1.5 kW or 5,118 BTU, because 120-volt wall outlets can only supply 12.5 amp constantly. In theory, you could make a space heater smaller then 1,500 watts but nobody does because electric coils are cheap to manufacture, and when you are warm, the thermostat just shuts off.
So every hour a heater heater is operating, it’s 1.5 kWh.


