All that's required is for the temperature of the waste heat to be higher for it to be a waste (assuming a close to carnot or reduced carnot efficiency). Of co

All that's required is for the temperature of the waste heat to be higher for it to be a waste (assuming a close to carnot or reduced carnot efficiency). Of course if your heat pump's efficiency doesn't scale with temperature ratio there might a way to use the heat to move it towards carnot efficiency.