Comment by avianlyric

You can use a heatpump for heating as well. Then not only do you get all the energy moved by the heat pump to warm a space. But you can also use the waste heat created by the heatpump for heating as well.

In a cooling scenario, all waste heat is just that, waste. But in a heating scenario, waste heat isn’t waste, it’s additional heat you can use, and reduces the total amount of energy you need to inject into the system.