Estimate heat-pump electricity and extra solar capacity using climate and COP assumptions. Compare existing heating costs and check seasonal performance limits.
Quick answer
Heat-pump kWh = useful heat BTU / (3,412 x seasonal COP); dedicated solar kW = annual kWh / loss-adjusted yield.
Notes updated 2026-10-06
- Best for
- Homeowners pressure-testing solar proposals before signing.
- Inputs needed
- electric usage, local rate, system size or quote assumptions
- Formula used
- Heat-pump kWh = useful heat BTU / (3,412 x seasonal COP); dedicated solar kW = annual kWh / loss-adjusted yield.
- Method references
- DOE heat-pump guidance
How much electricity will a heat pump add?
Useful heating demand divided by seasonal coefficient of performance determines electricity consumption. Floor area and climate are rough proxies; measured fuel use and a professional heat-loss calculation provide better inputs.
Can existing solar cover the new heating load?
Existing capacity alone does not prove spare production. This tool sizes dedicated solar for the additional annual demand and includes standard system losses. Winter grid imports and local export rules can change the financial outcome.
How does this heat pump solar estimate work?
Heat-pump kWh = useful heat BTU / (3,412 x seasonal COP); dedicated solar kW = annual kWh / loss-adjusted yield.
A worked example with explicit assumptions
A 40 million BTU useful heating load at seasonal COP 3.2 uses about 3,664 kWh. At $0.20/kWh that costs $733/year. At 1,400 kWh/kW/year it needs about 2.62 kW of solar.
What should I verify before using the result?
Floor area and climate are rough load proxies. Installer heat-loss calculations, seasonal COP and backup heat are needed for equipment selection.
Use your bill or written equipment quote, run a conservative scenario, and compare the result with the same inputs in another model.
References and next steps
Calculation notes updated 2026-10-06. Reference links explain the method; they do not establish a current utility tariff or installer price.
Read the full methodology or save and compare your solar plan.
Pressure-test the estimate
Treat the result as a planning range, not a promise. Re-run it with a lower and higher production estimate, your actual utility tariff, and the written installer quote.
- Check roof shade, orientation, tilt, and equipment losses.
- Separate cash price, financing fees, battery cost, and roof work.
- Verify export credits, fixed charges, and interconnection rules.
- Confirm incentive eligibility, deadlines, and tax treatment.
Sources behind this estimate
Use the method references below to check the formula and its limitations. Input defaults and illustrative scenarios are not current tariffs, guaranteed output or live installer quotes.
Utility export rates, eligibility rules, and installer pricing can change. Confirm the applicable tariff, interconnection requirements, and tax treatment before making a purchase decision.
Frequently asked questions
How do I use the heat pump solar calculator?+
Start with your actual usage, equipment or quote inputs, keep the displayed units, and change one assumption at a time. Floor area and climate are rough load proxies. Installer heat-loss calculations, seasonal COP and backup heat are needed for equipment selection.
What calculation does this tool use?+
Heat-pump kWh = useful heat BTU / (3,412 x seasonal COP); dedicated solar kW = annual kWh / loss-adjusted yield.
Can I check the arithmetic with an example?+
A 40 million BTU useful heating load at seasonal COP 3.2 uses about 3,664 kWh. At $0.20/kWh that costs $733/year. At 1,400 kWh/kW/year it needs about 2.62 kW of solar.
What could change the accuracy of my result?+
Floor area and climate are rough load proxies. Installer heat-loss calculations, seasonal COP and backup heat are needed for equipment selection.
Can I use the estimate outside the United States?+
Physical kW and kWh calculations use the same units internationally. Dollar results, regional defaults, emissions factors, incentives and utility guidance are US-oriented. Replace rate and production assumptions with local values; do not apply US tax or export rules abroad.
Can I print or save results without registering?+
Use Print / PDF to save this page from your browser without an email address. The solar plan stores supported scenario inputs in your browser; private files should be checked and redacted before uploading for extraction.
Compare the decision, not just the number
Compare cash, loan, lease, and battery scenarios using the same production, rate, and quote assumptions before choosing a financing path.
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