Your Flat Called. It Wants a Battery - Ashley Grealish, Windfall Energy

Half of European households live in flats or rented homes. For a decade, the clean energy transition has passed them by — smart tariffs assume an EV, rooftop solar assumes a roof, home batteries assume a wall you can drill into. Ashley Grealish has spent his career on exactly this structural gap: first at Bboxx, building pay-as-you-go solar for half a million homes in rural East Africa; then at ev.energy, scaling smart EV charging while pushing it beyond premium vehicles; now at Windfall Energy, with a 2.5 kWh plug-in battery that arrives overnight, plugs into a standard socket, and does the rest itself.

What this episode covers

System design over product design. At Bboxx, the team realised that importing a standard television into an off-grid kit didn't work — the power draw was too high. The solution was to rethink everything: low-power 12V appliances, right-sized panels, circular lead-acid battery recovery. The same logic is inside the Windfall battery: don't adapt the user to the system. Redesign the system around the user.

Affordability as architecture. Bboxx started at $400 upfront and couldn't reach most of the people it was built for. The shift to pay-as-you-go unlocked scale. Windfall is at the same first stage — £1,000 on pre-order, with a clear ambition toward zero upfront cost through energy supplier partnerships and, potentially, the UK Warm Homes Discount.

Desirability is not optional. Ashley filled his flat with test batteries from the European market. One arrived at 45 kg on a crate. Others had loud fans and permanent blue indicator lights. None were designed to be lived with. His conclusion: a product no one wants in their home will not reach the people who need it most.

Organisations mentioned: Bboxx · e.quinox (Imperial College) · GemFair · ev.energy · Windfall Energy · Warm Homes Discount (UK)

Marine Cornelis is the founder of Next Energy Consumer, a policy consultancy working on energy poverty, consumer rights, and housing at EU level. If you are working on a related mandate or research question, you can reach her at contact@nextenergyconsumer.eu

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