Britain’s sewage pumps are getting smart batteries as a start-up attempts to stop pollution before the next power outage.

Rheya combines battery backup power with software designed to predict wastewater spills
Power outages at pumping stations can turn routine power outages into environmental pollution
Rheya Battery Will Predict Underlying Causes of Spills Before They Happen

British start-up Rheya Labs has developed specially designed backup batteries to keep wastewater pumping stations running during power outages across Britain.

The company has been named one of 20 finalists in Ofwat’s £7.5m Water Discovery Challenge, run by the Water Innovation Fund.

Each finalist receives up to £100,000 in seed funding, part of a wider pot of £7.5 million distributed over 20 months.

A different approach to an old problem

Sewage spills are a common and long-standing problem, often blamed on overloaded systems or heavy rains.

England recorded around 290,000 wastewater releases from storm overflows in 2025, lasting a total of around 1.9 million hours across the entire network.

Power outages at pumping stations are widely recognized as one of the triggers for these spills, alongside heavy rains and aging infrastructure.

Rheya Labs is currently working on a system that combines instant battery backup with software designed to flag faults before they cause spills.

In the event of a power outage, Rheya’s batteries instantly take over from the pumps, preventing raw sewage from flowing into rivers and streets.

The system also applies machine learning to pump data, with the aim of predicting the underlying causes of spills before they occur.

Co-founder Ben Taylor said sewage pollution remains an ever-growing crisis in the UK, calling the electrical resilience of pumping stations a hidden but major cause.

Predictive analytics can give Rheya the edge

Elsewhere, Sydney Water has trialled sodium-ion batteries at its Bondi pumping station, providing a cheaper alternative to lithium-ion systems.

This Australian project, supported by a $10.6 million grant, combines a 30 kWh sodium-ion pack with rooftop solar generation for backup power.

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

Unlike those systems, Rheya’s technology would combine instant backup power with predictive analytics, potentially detecting outages before they actually occur.

“With our rapidly changing climate, it is more vital than ever that we redouble our efforts to create a water system that can support lives and livelihoods,” said Jo Jolly, Ofwat’s chief innovation officer.

“The range of new ideas coming from new actors is staggering. The challenge is to ensure that these ideas have an impact on the ground, with the sense of urgency that modern times need.”

So far, Rheya’s approach has not been proven to actually outperform established sodium-ion and lithium-ion systems outside of controlled trials and early pilot deployments.

Independent verification of Rheya’s claims about spill predictions has yet to be publicly tested, leaving early results largely anecdotal for now.

Up to ten finalists, including Rheya, will each share £550,000 next April, funding further testing before a wider rollout across the water network.

The success of this project will ultimately depend on whether the predictive software will match the reliability already demonstrated by simpler alternatives to sodium and lithium.

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