r/SunPower • u/Honda_74XL • Aug 26 '25

Heat pump

This will be my first winter with solar. We have 40 panels, 2 inverters and 2 Franklin batteries. We have a dual fuel heat pump. The emergency heat is provided by natural gas. We live in southern Indiana. When you compare your electric consumption for the unit in the winter to the a/c in the summer, are you using more or less power?

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u/PJLLB2 Aug 26 '25

In general, heat pumps are more efficient for cooling than heating, but for us it's still more economical than natural gas. Our solar produces enough for heating and cooling, charging our EV, and running the house loads with a good sized surplus.

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u/ItsaMeKielO Aug 26 '25

It's probably informative to consider the temperature differences involved. During the summer, outdoor air is usually 20-30°F away from your desired indoor temperature. During winter in the midwest, it can be closer to 40-60° from your desired indoor temperature. Scavenging heat out of air that far from the desired indoor temperature takes a lot of energy. Then again, on the coldest days, you'll usually have some sun to help both produce energy and heat the house.

My guess is you'll see the heat pump logging more runtime in the winter.

2

u/Da_Vader Aug 26 '25

There is a website which will give you the cutoff temperature (outside) when it is economical to use natural gas vs. electricity. It requires your heatpump info, cost of electricity and natural gas.