Heating: heat pumps vs gas vs oil
For most temperate climate homes, heating is the single biggest line item in the annual carbon budget. Here's how the main fuel options compare on emissions and what "electrify heating" actually means in practice.
Per-kWh emissions, by fuel
DEFRA factors per kWh of heat delivered to the home (gas/oil) or per kWh of heat output (heat pump / district).
| Fuel | kg CO2/kWh | 12,000 kWh/yr |
|---|---|---|
Heat pump (electric, mild climate, COP 3) kg CO2 per kWh of heat delivered, on a typical EU grid | 0.061 | 0.73 tCO2 |
District heating (EU average) varies widely by country | 0.140 | 1.68 tCO2 |
Natural gas boiler DEFRA 2024 | 0.183 | 2.20 tCO2 |
Oil boiler DEFRA 2024 | 0.247 | 2.96 tCO2 |
Wood / biomass short-cycle, treated as non-fossil | 0.020 | 0.24 tCO2 |
Heat pump emissions by country grid
A heat pump is only as clean as the grid it runs on. Same unit, same heat demand, different country: emissions vary by an order of magnitude. Assuming COP 3 (one kWh of electricity yields three kWh of heat).
| Country | Grid intensity | Heat-pump kg CO2/kWh heat |
|---|---|---|
| 🇫🇷France | 56 g/kWh | 0.019 |
| 🇳🇴Norway | 30 g/kWh | 0.010 |
| 🇸🇪Sweden | 45 g/kWh | 0.015 |
| 🇨🇭Switzerland | 44 g/kWh | 0.015 |
| 🇬🇧United Kingdom | 235 g/kWh | 0.078 |
| 🇩🇪Germany | 385 g/kWh | 0.128 |
| 🇵🇱Poland | 660 g/kWh | 0.220 |
| 🇺🇸United States | 369 g/kWh | 0.123 |
| 🇨🇦Canada | 116 g/kWh | 0.039 |
| 🇯🇵Japan | 480 g/kWh | 0.160 |
| 🇨🇳China | 581 g/kWh | 0.194 |
| 🇮🇳India | 632 g/kWh | 0.211 |
What this means in practice
- Gas → heat pump on a clean grid (FR, NO, SE, CH) cuts heating emissions by ~95%.
- Gas → heat pump on a dirty grid (PL, IN) still cuts emissions, but only by ~25%. The win compounds as the grid decarbonizes.
- Insulation comes first. A heat pump that runs at half capacity in a well-insulated home beats a heat pump that compensates for poor insulation.
- Oil and direct electric resistive are the worst combinations on most grids. Switch order of operations.
Sources
- UK DEFRA GHG Reporting Conversion Factors 2024
- IEA Electricity Information — country grid carbon intensity.