Why Heat Pumps and Solar Are a Natural Combination
A heat pump is an electric appliance. It heats your home using electricity rather than burning gas or oil. When you combine a heat pump with solar panels, your solar system can offset much or all of the electricity the heat pump consumes — turning what was a gas bill into solar-generated heat.
The combination works because:
- Heat pumps are dramatically more efficient than electric resistance heating — they deliver 2–4 units of heat energy for every unit of electricity consumed
- Solar panels generate free electricity during daylight hours, which can directly power the heat pump or offset its consumption through net metering
- Together, they can eliminate both your electricity bill and your gas bill
How Heat Pumps Work
A heat pump doesn't generate heat — it moves it. In heating mode, it extracts heat energy from outside air (even cold air contains heat energy) and moves it inside. In cooling mode, it works like a conventional air conditioner, removing heat from inside and releasing it outside.
The efficiency advantage: a heat pump might use 1 kWh of electricity to deliver 3–4 kWh of heat energy into your home. An electric resistance heater converts 1 kWh of electricity to exactly 1 kWh of heat — no better. A gas furnace converts fuel to heat with losses. Heat pumps win on efficiency.
Cold Climate Heat Pumps in Illinois Winters
Standard heat pumps from previous generations lost efficiency rapidly in cold weather and often couldn't operate below about 25°F, relying on backup electric resistance heat in very cold conditions. Modern cold-climate heat pumps have improved significantly. Leading products are rated to operate efficiently down to 0°F or below.
For Illinois winters, which regularly produce temperatures below 0°F in January and February, a cold-climate rated heat pump with a backup heat source (either electric strip or dual-fuel with a gas furnace) is the appropriate configuration. SPM evaluates each home's heating profile before recommending a heat pump system.
ComEd has offered rebates on qualifying cold-climate heat pumps through its Energy Efficiency Program. Rebate availability and amounts change — verify current offerings directly with ComEd before budgeting.
How Adding a Heat Pump Affects Solar Sizing
This is where many homeowners get confused: adding a heat pump increases your electricity consumption, which means a larger solar system is needed to offset it. But the overall financial picture is still often favorable because:
- You're eliminating your gas bill (or most of it)
- The heat pump's electricity consumption is more efficient than the gas it replaces
- Solar can offset the added electrical load, so your net energy cost can still go down significantly
The key is to size the solar system to account for the heat pump's added electrical load from the beginning — not to install solar first (sized for your current electric-only usage) and then add a heat pump later, which would leave the solar undersized.
SPM evaluates the heat pump and solar system together when both are being considered, so the solar sizing reflects the home's actual post-conversion electrical profile.
The Gas Elimination Math
For a home currently using natural gas for heating, the economic case for heat pump + solar looks like this:
- Gas bill: eliminated or greatly reduced
- Electric bill: increases due to heat pump consumption
- Solar offsets the increased electric bill: net electric cost approaches zero
- Net result: both heating and electricity costs are greatly reduced or eliminated
The specific numbers depend on your current gas usage, heat pump efficiency rating (COP), your solar system size, local electricity rates, and net metering terms. SPM models this for your specific home before recommending a combined system.
The Sequence That Makes Sense
For homeowners planning both a heat pump and solar:
- Assess the home's efficiency profile first — windows, insulation, envelope
- Determine whether the existing HVAC needs replacement (or whether the heat pump replaces an aging system)
- Size the solar system to cover the home's total post-heat-pump electrical load
- Install both in a coordinated sequence, or in a phased plan that accounts for the solar sizing implications
Frequently Asked Questions
Does a heat pump work as well as a gas furnace in an Illinois winter?
A modern cold-climate heat pump with appropriate backup heat is an effective heating solution for Illinois. At very low temperatures (below 0°F), most heat pumps reduce efficiency and rely more on backup heat. For the majority of Illinois heating days, the heat pump operates efficiently. The backup heat source handles the coldest days. The overall heating season performance is typically very good.
Should I replace my HVAC with a heat pump before going solar?
If your HVAC system is approaching end of life (typically 15–20 years for a furnace or AC), replacing it with a heat pump before sizing solar is the right sequence — it lets the solar system be sized for the post-conversion electrical load. If your HVAC is newer and functioning well, you may want to defer the heat pump and size solar for your current load.
What about gas backup with a heat pump?
A dual-fuel system pairs a heat pump with a gas furnace as backup. The heat pump handles most heating (efficiently), and the gas furnace kicks in during the coldest days when the heat pump's efficiency declines. This configuration reduces gas usage significantly without requiring full gas elimination — and may be appropriate for homes with very cold microclimates or where full gas service elimination isn't practical.
What brands does SPM install for heat pumps?
Contact SPM for current equipment recommendations. We select equipment based on your home's specific load, layout, and climate requirements.
Interested in evaluating heat pumps and solar together for your home? Learn about SPM's heat pump service or get a free whole-home energy assessment.