Air source heat pumps are an incredible investment in your home’s energy efficiency, but the energy savings don’t have to stop there. Powering your heat pump system with solar panels can maximize energy bill savings while decreasing your carbon footprint. But how do you size a solar system to meet your heating and cooling needs? In this article, we break down what you need to know and discuss with your solar installer to ensure your solar system can power your heat pumps.
On average, you’ll need somewhere between 8-23 solar panels to power an air source heat pump or 3-5 to power mini splits, but this will vary greatly based on the factors we outline in this article.
Air source heat pumps increase energy efficiency, but can still be powered by fossil fuels. Solar panels allow for emission-free electricity for all of your home’s energy needs.
There are two major factors that determine how many additional solar panels you need to power air source heat pumps: how much electricity they’ll use and the solar potential of your home.
Determining how much electricity an air source heat pump will use depends on the system’s design, efficiency, your property, geography, and your personal temperature preferences.
Heat pump systems are highly individualized, which can make determining how many solar panels you’ll need before installing your heat pump system complicated. Use the EnergySage Marketplace to find local professionals to help you along the way.
Covered in this article
There are three main steps to estimating how many solar panels you need to power air source heat pumps for your home:
1. Estimate your electricity use from air source heat pumps
Air source heat pump technology has evolved to fit various heating and cooling needs – you can now buy heat pumps designed for only one room (a single-zone system) or those that can heat and cool multiple zones throughout your house; there are also central ducted systems or ductless mini splits! While this means that more homes have the ability to enjoy the benefits of heat pumps, it makes estimating an air source heat pump’s electricity needs a bit more complicated.
The model of the heat pump and the area of the space it’s expected to heat and cool aren’t the only factors to consider when estimating the energy usage of air source heat pumps. The geography and insulation of your home play a crucial role in energy expenditure: a well-insulated home is better at retaining heat in the winter than one with poor quality insulation, and therefore won’t require as much electricity to heat.
The Department of Energy (DOE) estimates that given 1,400 hours of both heating and cooling a year (2,800 hours of use total), a 36,000 BTU/h central ducted air source heat pump consumes between roughly 5,000 and 10,000 kWh annually depending on the efficiency of the model you choose:
Average air source heat pump electricity usage Heat pump performanceAnnual electricity usage (kWh) Highest efficiency5,123 kWh ENERGY STAR Certified9,289 kWh Lower efficiency9,746 kWh
These consumption numbers are indicative of a property using air source heat pumps as their primary heating source. Units designed to heat larger spaces will likely consume more electricity, while ductless mini-splits heating and cooling either smaller homes or only a single zone should consume less. Because the energy needs of these technologies are so specific to your property, geography, the efficiency of the product, and your heating and cooling habits, the best way to get an accurate estimate for anticipated electricity consumption is to obtain a quote from a qualified contractor.
2. Predict your solar production
Similar to air source heat pump energy usage, there are many factors that contribute to the solar potential of your property. In addition to the region you live in, the location of your solar panels plays an important role in energy production. Everything from their tilt and the direction they face to the amount of shade impacts the production potential of a solar array.
Below are some rough estimates of the annual generation of a solar panel in various regions. For the purposes of these estimates, we assumed 400-watt (W) solar panels, which have been the most frequently selected panels on the EnergySage Marketplace in the first half of 2022.
Average production per solar panel by U.S. region RegionAnnual electricity production per solar panel (kWh) Northeast (e.g. MA, NY)460 kWh Mid-Atlantic (e.g. MD, VA)490 kWh Southeast (e.g. FL, GA)540 kWh Midwest (e.g. IL, OH)480 kWh Southwest (e.g. AZ, TX)660 kWh Pacific Northwest (e.g. OR, WA)430 kWh Mountain West (e.g. CO, UT)580 kWh West Coast (e.g. CA)640 kWh
Based on these estimates, you will need between two to three 400 W solar panels to generate 1,000 kWh in a single year. But as previously mentioned, this is heavily dependent on the specifics of your geography, property, and solar array design, so it’s important to confirm any estimates with a professional installer.
3. Match consumption with output
Once you understand the electricity needs of your heat pump and the solar potential of your home, you’re ready to calculate how many solar panels you might need to run your air source heat pump. To roughly estimate what it will take to cover the heat pump’s energy needs, simply divide your air source heat pump’s estimated annual electricity consumption by the expected output of a 400-watt solar panel in your region. Using the scenario above, a central ducted air source heat pump system would require: Performance of heat pump# of solar panels required Highest efficiency8 - 12 ENERGY STAR certified14 - 22 Lower efficiency15 - 23
Once again, these numbers reflect a system that serves as the primary source of heating and cooling. Other technologies, like ductless mini splits, or smaller systems require less electricity and therefore require fewer solar panels. For example, an efficient 12,000 BTU mini split system that consumes around 2,000 kWh annually would need between three and five solar panels.
Compare quotes for solar and heat pumps
Now that you’re equipped with the knowledge of how to estimate the number of solar panels required to power an air source heat pump system, you’re ready to start comparing quotes from local solar installers. What is the wattage of the solar panels they are quoting? Where will the solar panels go on the property? How efficient is the air source heat pump model you want to power with solar? It’s important to think about things like this when comparing professional estimates.
Even still, it’s best to consult a local installer to understand the energy needs of both your air source heat pump and solar panel systems. When you receive quotes through the EnergySage Marketplace, we’ll even connect you with an Energy Advisor to guide you through each quote, free of charge!