Understood, but the heat pump, itself, depreciates. They're good for about 10 years, out here, so you'd have to knock 900$/yr off the "investment". That takes i

Understood, but the heat pump, itself, depreciates. They're good for about 10 years, out here, so you'd have to knock 900$/yr off the "investment". That takes it down to 6%, which is better than a high yield savings account, for sure. My suspicion is that the folk who make these heat pumps are well aware of the pricing structure in central Texas.