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. Useful before buying a heat pump or filing for electrification rebates.

Annual heat demand (delivered) (kWh/yr)

Heat pump COP (seasonal average)

Electricity price ($/kWh)

Furnace / boiler efficiency (%)

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

Annual heating savings

435.29 $/yr

No savingsMarginal savingsSolid savingsStrong savings

$200-600/yr is the common range versus gas at moderate rates. The $435 example (COP 3, $0.07 fuel) recoups a typical $4-6k cost premium in roughly 10-14 years.

Savings compare delivered-heat fuel cost against heat-pump electricity cost; a positive number means the heat pump is cheaper to run, driven mainly by COP versus furnace efficiency and the electricity-to-fuel price ratio.

Solar Energy

Solar Panel System Sizing Calculator

Calculate exactly how many solar panels your home needs based on your electricity bill, local sun exposure, panel wattage, and desired offset. Ideal for homeowners planning a rooftop PV installation.

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)

Solar panels needed

21 panels

Lean sizingStandard full offsetLow-sun sizingOversized or low-sun

9.33: 7-10 W per monthly kWh is the normal range for a 100% offset at 4.5-5.5 sun hours. The example (9.3 W/kWh: 21x400W panels for 900 kWh) sits here.

This is installed watts per kWh of monthly usage; the formula's own math ties panel count to your offset target, sun hours, and losses, with ~7-13 W per monthly kWh being typical.

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. Useful before buying a heat pump or filing for electrification rebates.	Calculate exactly how many solar panels your home needs based on your electricity bill, local sun exposure, panel wattage, and desired offset. Ideal for homeowners planning a rooftop PV installation.