Solar · Advice
Should I get a solar diverter or a battery?
Short answer
A solar diverter sends surplus electricity to an immersion heater, costs a few hundred pounds and is worth it if you have a hot-water cylinder and low export rates. A battery costs thousands but can power anything, shift cheap night electricity and provide backup. Many homes with a cylinder benefit from both.
Last checked 24 September 2026 · 1 source
In more detail
- Diverter value = kWh diverted x (price of the fuel it replaces - export rate forgone). If gas heats water, value per kWh is low; if an immersion or no gas, value is higher.
- With a heat pump cylinder, diverting to the immersion (COP 1) is usually less efficient than running the heat pump (COP 2-3) at midday.
- Batteries cost GBP 5,000-8,000 (EST).
The facts, dated
- 01Battery storage typically GBP 5,000-8,000 (EST) — 5000-8000 GBP
market_data · UK · checked 24 September 2026 · Energy Saving Trust
Sources
- Energy Saving Trust — energysavingtrust.org.uk/advice/solar-panels/
Last checked: 24 September 2026