UK startup targets sewage spills with battery backup tech

A UK startup is pitching a new fix for one of Britain’s dirtier infrastructure problems: sewage spills triggered by power failures at pumping stations. Rheya Labs has developed backup batteries designed to keep those pumps running during blackouts, and it says its software can spot faults before they lead to spills.

The company is one of 20 finalists in Ofwat’s £7.5 million Water Discovery Challenge, run by the Water Innovation Fund. Each finalist receives up to £100,000 in seed funding as part of a wider £7.5 million pool distributed over 20 months.

Sewage discharges remain a major issue in England. The source says the country recorded around 290,000 sewage discharges from storm overflows during 2025, lasting roughly 1.9 million hours in total. While overloaded systems, heavy rainfall, and ageing infrastructure are often blamed, power failures at pumping stations are also a recognized trigger.

Rheya’s approach combines two pieces: instant battery backup when a power cut hits, and machine learning applied to pump data to predict the causes of spills before they happen. According to co-founder Ben Taylor, sewage pollution is an escalating crisis in the UK, and weak power resilience at pumping stations is a largely overlooked factor.

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How Rheya compares with other sewage backup projects

The idea enters a field where battery-backed sewage infrastructure is already being tested elsewhere. Sydney Water has trialled sodium-ion battery packs at its Bondi pumping station, backed by a $10.6 million grant. That project combines a 30-kWh sodium-ion pack with rooftop solar for backup power.

In New York, Viridi’s 150 kWh lithium-ion battery system replaced diesel generators and can provide backup power for between 32 and 90 hours.

Rheya’s distinction, according to the source, is the addition of predictive analytics alongside instant backup power. But that edge is still unproven outside controlled trials and early pilots, and independent public verification of its spill-prediction claims has not yet appeared.

“With our rapidly changing climate, it is more vital more than ever that we double down on our efforts to create a water system able to support lives and livelihoods.” “The array of new ideas from new players is astounding. The challenge is getting these ideas delivering impact on the ground, with the sense of urgency these times need.”

Up to ten finalists, potentially including Rheya, will share £550,000 each next April to fund further testing before any broader rollout across the water network.