The oxygen byproduct does not figure favorably unless it can more than pay for itself. Seems like the same amount of electricity will always have more energy t

The oxygen byproduct does not figure favorably unless it can more than pay for itself. Seems like the same amount of electricity will always have more energy than the amount of hydrogen it can be turned into. Takes theoretically a minimum of 39 kwh of electricity to make 1 kg of H2. Decently efficient processes still use up 48 kwh so far to make 1 kg of H2 since they are not perfect. 1 kg H2 yields 120 to 140 MJ when burned or probably the lower of 33 to 39 kwh depending on how you calculate the heat. Keeping in mind the only way to get 39 kwh back out is if the byproduct oxygen actually consumed none of the electricity during the gas production.[0] Probably quite a bit lower for domestic heating due to losses out of exhaust flues that are necessary. Indoor heating using the same electricity will always be more efficient than turning the electricity to hydrogen first. [0] didn't calculate that far myself to be sure.