What inputs do I need?

Enter a heat demand (kWh of heat), choose the period, and set the efficiencies: COP for heat pumps, electrical resistance efficiency, and gas boiler efficiency. Edit electricity price, gas price, grid carbon intensity, and gas CO₂ factor as needed.

For each system we calculate energy in (kWh of electricity or gas), cost (× price), and CO₂ (× grid intensity or gas factor). Results are shown per chosen period and per year.

Does it upload my data?

No. Everything runs locally in your browser.

Electricity vs. Gas Heating — Efficiency, Cost & CO₂

Friendly estimates for planning and awareness. Private by design — runs locally in your browser.

Heat Demand & Factors

Heat demand Period Season length (days)

System Efficiencies

Heat pump COP Electric resistance efficiency (%) Gas boiler efficiency (%)

Prices & Emission Factors

Electricity price (per kWh) Gas price (choose units) Gas price

Grid intensity (kg CO₂ / kWh) Gas factor (kg CO₂ / kWh) Upstream methane add-on (gas) %

Advanced (optional)

Days per year Therm → kWh

Use the methane % to include a CO₂e uplift for gas supply (awareness-level). All factors are editable.

Friendly estimate only. Real homes vary with climate, setpoints, insulation, hot water draws, and equipment performance.

Results

How This Heating Comparison Works

You supply a heat demand (kWh of heat). Each system delivers that heat with its own efficiency: electric resistance ≈ 100%, heat pumps ≈ COP 2–4, and gas boilers ≈ 85–95%. We convert heat to required energy in, then multiply by your prices and emission factors.

Heat pump electricity in: heat ÷ COP
Electric resistance electricity in: heat ÷ (eff%)
Gas energy in: heat ÷ (boiler eff%)
CO₂: electricity kWh × grid kg/kWh; gas kWh × gas kg/kWh (optional upstream % adds proportionally)

Tip: Try COP 3.0 as a season average; colder days are lower, mild days higher.

FAQs

What should I enter for heat demand?

Use your best estimate. For daily space heat, try 20–60 kWh/day in winter for a typical home; for annual totals, use your past bills or an energy audit.

Why does the heat pump often win?

Heat pumps move heat instead of making it—so their COP can be 3+, meaning 1 kWh in ≈ 3 kWh of heat out.

Is gas factor exact?

No—0.184 kg/kWh is a common HHV-based tailpipe CO₂ figure. Regions differ; edit to match your source. You can add an upstream % if you want CO₂e awareness.