How many solar panels do I need for heat pumps?

Heat pumps are an incredible investment in your home's energy efficiency, but the savings don't have to stop there. Powering your heat pump with solar panels essentially guarantees lower energy costs while decreasing your carbon footprint even more than a heat pump alone. 

More than half of a typical home’s energy use goes toward heating and cooling—if you run your HVAC with clean solar power, you can shrink your power bills, and you’re well on your way to a net zero home. 

Plus, the cheaper you can make your electricity, the better the chances you’ll save money in the long run by switching to a heat pump for your heating and cooling. 

So, how do you size a solar power system to match the needs of a heat pump? We’ll show you how to estimate.

Based on an EnergySage analysis of a Department of Energy database, the median annual electricity use for a typical heat pump in the U.S. is about 5,475 kWh per year. The likely range is anywhere between 400 kWh and 22,500 kWh, depending on your house, climate, and some details about the heat pump itself. We get into a lot of those nuances and possibilities in another article, but you can use the table below for some rough estimates.

Average heat pump electricity usage (kWh)

Heating efficiency: sCOP 2.5. Cooling efficiency: SEER 15. Lower percentiles are more likely to represent smaller, more efficient homes. Units in kWh.

All of these figures assume that a heat pump will be your home's sole heating and cooling system. Today’s high-performance models can actually pull that off, even in extremely cold climates.

Of course, you’d budget for less energy use if installing a mini-split for only a part of your home. We’ve also made some estimates (based on the DOE database) for the amount of electricity a heat pump might use per square foot, which can be a decent way to estimate a partial home system's energy use. 

Backup or hybrid heating systems for cold weather can change the math, too. Electric strip heat will increase electricity usage, while a fossil-fuel system will decrease it. We don’t have good estimates for either of these scenarios because they depend on too many fine details, but an HVAC pro can help you get a ballpark estimate.

Some parts of the U.S. get more sunshine (and snow) than others, and some roofs are laid out for better sun exposure, depending on the direction, tilt, and shading. That all affects how much electricity your solar panels produce in a year.

Installers who bid on projects through the EnergySage Marketplace usually include production estimates in their quotes. We’ve analyzed those estimates and put together some rough guidelines for typical annual solar panel generation in different parts of the country. 

These numbers assume that you’d install 450-watt solar panels. 

Average production per solar panel by U.S. region

Again, these are just estimates, and your solar installer might make different projections based on your roof shape, nearby shading, and the local weather. 

They also don’t account for the cash value of your solar energy, which can vary based on incentives and billing policies. (More on that below)

Once you have an idea of how much energy you’ll need to run a heat pump in your home and how much energy you could produce per panel per year, you can do some simple math to get a sense of how many solar panels you’ll need to offset a heat pump’s electricity usage. 

The estimates vary wildly depending on your home and local climate, so plug in the numbers as accurately as possible. Some examples:

If you’re eligible for solar net metering (that is, full credit for solar power on your electric bill), then your estimate is complete. That’s how many solar panels you'll need to match your heat pump’s energy consumption.

The math might look different if your utility company offers a partial billing credit (they buy your excess solar for a discount). 

One option is to install extra solar panels. This can make sense when the utility’s markdown is pretty modest (like in Michigan). 

But if it’s a big billing penalty (like under California’s new rules), it typically makes more sense to add battery storage so you can hoard more of your solar power instead of giving it away to the utility company.