Nobody asks Windfall Energy how much carbon its battery saves. They ask how much money it will save them.
Around 14 million UK homes, roughly half the housing stock, are rented, flats or too small for rooftop solar and a garage battery. Those households have been locked out of the cheapest energy available. Rob Hallifax, co-founder of Windfall Energy, is building a plug-in home battery for them: 2.5kWh, 25kg, delivered by courier, and designed to sit in the corner of a living room rather than bolted to a garage wall.
The commercial case is simple. The battery fills up when electricity is cheap and powers the home when it is expensive, worth around £250 a year. Roughly two thirds comes from the gap between peak and off-peak prices, and a third from grid flexibility markets. At around £1,000, that is a three to five year payback, and because it plugs in, you take it with you when you move.
In this conversation, Richard and Rob get into why balcony solar is still a niche answer, the regulatory gap that currently separates plug-in solar from plug-in batteries, how Windfall is handling battery safety, and why manufacturing 100 units is harder than manufacturing 100,000. They also discuss why selling through energy companies, with a tariff built around the battery, could be the key to reaching millions of homes.
It’s a practical conversation about turning hardware, software and a deeply unglamorous tariff problem into a consumer product people actually want in their homes.
