I don't understand how that means it's more efficient though. Don't you need to put that heat energy back into the environment to heat it back up again? To me

I don't understand how that means it's more efficient though. Don't you need to put that heat energy back into the environment to heat it back up again? To me that feels like calling a magnet perpetual motion. It seems like it is, but the magnet will eventually wear out. That's like saying this LED is over 100% efficient. It seems like it, but eventually the environmental heat around it will be gone and used up.