Compare calculators

Both calculators run independently — change the inputs on either side to compare results.

Heat Pump Savings Calculator (vs Gas or Oil)

Compare the annual heating cost of a heat pump against a gas or oil furnace using your heat demand, the heat pump's COP, furnace efficiency, and both fuel prices.

Annual heat demand (delivered) (kWh/yr)

Heat pump COP (seasonal average)

Electricity price ($/kWh)

Furnace / boiler efficiency (%)

Fuel price (per kWh equivalent) ($/kWh)

Solar Energy

Solar Panel System Sizing Calculator

Size a rooftop solar PV system from your real electricity usage, local peak sun hours, system losses, and your target offset — and get the number of panels you actually need.

Average monthly electricity use (kWh)

Peak sun hours (daily average) (h/day)

Share of usage to offset (%)

System losses (inverter, wiring, soiling, heat) (%)

Panel power rating (W)

Key differences

	Heat Pump Savings Calculator (vs Gas or Oil)	Solar Panel System Sizing Calculator
Category	Solar Energy	Solar Energy
Inputs required	5	5
Result	Annual heating savings ($/yr)	Solar panels needed (panels)
What it does	Compare the annual heating cost of a heat pump against a gas or oil furnace using your heat demand, the heat pump's COP, furnace efficiency, and both fuel prices.	Size a rooftop solar PV system from your real electricity usage, local peak sun hours, system losses, and your target offset — and get the number of panels you actually need.