The space heaters are virtually 100% efficient at putting energy I pay for into the room, with no duct loss. And here the energy is produced by hydroelectric and nuclear. There are essentially no diseconomic factors.
Very true that’s why I mentioned the losses are at the generation station. Still 100% in the home, so the loss isn’t to the homeowner except in the bills. If hydro and nuclear were used more than coal (53% of the time) I would guess more of us would use electric heaters.