What is Solar Diverter?
A device that automatically redirects surplus solar electricity to heat your water tank instead of exporting to the grid.
Quick Answer
Solar diverters are popular in the UK, costing £250–£500 installed. Popular models include the Eddi (myenergi) and Solar iBoost. With UK export rates at 3–15p/kWh and grid electricity at 24–34p/kWh, diverting surplus solar to heat water saves 10–30p per kWh diverted. A diverter can save £150–£350 per year on water heating costs.
Fact-checked by John Rooney, Solar Energy Editor. Editorial policy
Solar Diverter Explained
A solar diverter (or power diverter) is a device that monitors your solar generation and household consumption in real time. When it detects surplus electricity that would otherwise be exported to the grid, it automatically diverts this power to an immersion heater in your hot water cylinder. This maximises self-consumption by using surplus solar energy to heat water instead of selling it at the lower export rate.
How Does Solar Diverter Work in the UK?
Solar diverters are popular in the UK, costing £250–£500 installed. Popular models include the Eddi (myenergi) and Solar iBoost. With UK export rates at 3–15p/kWh and grid electricity at 24–34p/kWh, diverting surplus solar to heat water saves 10–30p per kWh diverted. A diverter can save £150–£350 per year on water heating costs.
Frequently Asked Questions
Is a solar diverter better than a battery?
A diverter is much cheaper (£350 vs £3,500+) and has a faster payback. However, it only heats water. A battery stores electricity for any use. Many homes benefit from both.
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John Rooney is the founder of Solar Info and has been covering the UK solar energy market since 2023. He fact-checks all content against official MCS and Ofgem data and maintains relationships with MCS-certified installers across the UK.