Protecting rivers and reputation with Greener Upgrades solution

The United Utilities wastewater treatment site is located in a remote rural location on the moors. This made it susceptible to power cuts, increasing the risk of discharge into the nearby rivers and potential pollution. United Utilities is clear on its environmental responsibilities and has proposed a major improvement programme to reduce storm overflow operation over the period up to 2030. With this in mind, United Utilities tasked its own graduate engineers to develop a deployable and scalable mitigation strategy. This is an annual process within the company’s Graduate Scheme whereby the CEO and Executives challenge innovative thinking from the graduates. We were proud to lend our expertise to support a lasting solution.

While the standard solution would be to have a standby generator on an automatic mains failure system, this would mean a break in power, and any delay while an operator reset the equipment would increase the risk of a spill to the environment.

Our solution was to use one of our new BESS systems with the mains power passing through the unit. In the event of a power outage, the BESS inverters would change state and start powering the pumps automatically until the mains was restored.

First, we needed to understand how the pumps operated, their power consumption, startup and running currents, plus how long the customer wanted them to run to reduce the risk of discharge. We had to calculate the loads and decide which sized system would be best suited to run the pumps for the time required. We decided our 90 kVA / 120 kWh BESS would work best.

A module fitted to the system automatically sent an email every time the inverter changed state, ensuring both our technicians and our client would know exactly when the mains supply had been lost and when the battery was powering the pumps. To maximise peace of mind, the equipment was set up in our Widnes depot and tested to ensure the unit preformed as expected.

Our battery energy storage system has provided complete resilience, delivering essential backup power during regular power outages and reducing the threat of pollution. 

​Our Greener Upgrades were initially commissioned for a 3-month period in 2023. Thanks to their success in keeping the pumps running and a clean river flowing, this contract has now been extended twice to the end of 2024, while our customer examines proposals for a permanent solution.