Improved water supply system could also produce electricity

They hope to develop technology to utilise excess pressure in the system to produce electricity that can be used locally or sold back to the grid — while, at the same time, reducing CO₂ emissions and operating costs associated with supplying treated water.

‘The water industry is very energy intensive. This project could help reduce its associated environmental impact and economic costs,’ said Dr Prysor Williams of Bangor — with colleague Dr Aonghus McNabola of Trinity adding that the technology could also potentially reduce metering charges for individual customers.

Water supply involves considerable energy consumption, cost and CO₂ emissions in water treatment, pumping and monitoring. Treated water is most commonly supplied to a community from a central storage reservoir by gravity throughout a catchment system, and this water must be supplied within satisfactory pressure bands. 

Where the pressure in water flow becomes too high, a Break Pressure Tank (BPT) is commonly installed in the network, whereby the pressure, kinetic and potential energy within the flow is dissipated to the atmosphere. These BPTs present an opportunity to recover energy from water-supply networks by means of a hydropower turbine system, producing electricity without interfering with the water supply service.