Efficiency Comparison
An electric boiler converts electricity to heat at ~99% efficiency — 1 kW of electricity gives ~1 kW of heat. A heat pump achieves CoP 3.0–4.5, meaning 1 kW of electricity gives 3–4.5 kW of heat. The heat pump is 3–4× more efficient.
Running Costs
For a 12,000 kWh annual heat demand at 24p/kWh: Electric boiler: £2,880/year. Heat pump (CoP 3.5): £823/year. The heat pump saves approximately £2,000/year in running costs.
Installation Costs
Electric boiler: £1,500–£3,000. Heat pump: £4,500–£10,500 after BUS grant. Payback from energy savings: 3–5 years.
Verdict
A heat pump is significantly more efficient and cheaper to run than an electric boiler. The higher upfront cost is recovered in 3–5 years through running cost savings. For any significant heating load, a heat pump is clearly the better choice.
Sources: electricity unit rate.
