New concept could lead to energy-efficient water supply technology

The water industry, their consumers and the environment could benefit from a new research project to assist the industry to cut its energy bills.

Researchers from Bangor University and Trinity College Dublin have identified a way of using water pressure within the water storage system to generate renewable energy. That energy can then be used by the water industry and sold to the grid.

The researchers have been awarded £500,000 in EU funding to investigate and develop small hydropower turbines that could be introduced within existing water treatment systems. These could reduce the amount of energy used in the water supply process. This will enable the water industry to reduce its CO₂ emission and to reduce the operating costs of supplying treated water.

“The water industry is very energy intensive. This project could help reduce its associated environmental impact and economic costs” explained Dr Prysor Williams of Bangor University’s School of Environment, Natural Resources & Geography (SENRGY).

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 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 are widespread, and present an opportunity to recover energy from water supply networks by means of a hydropower turbine system, producing electricity and improving the sustainability of the network without interfering with the water supply service.” explained Dr Aonghus McNabola of Trinity College Dublin.

Said Rhys Lewis, Process Science Manager for Welsh Water: “We have many break pressure tanks fitted which fit this criteria. Recovering energy fits perfectly with Welsh Water’s strategy to reduce its carbon footprint and we are looking forward to collaborating on this exciting project.”

The Hydro-BPT concept is being investigated from three perspectives. Firstly, the engineering design and technical feasibility are being investigated by Trinity College Dublin’s School of Engineering; secondly the organisational and business model for the implementation of this new technology in practice is being developed by Trinity College Dublin’s Business School. Finally, the potential environmental impacts of the technology (energy resource and CO₂ emissions savings) are being investigated by Bangor University.

The three-year project was awarded funds from the ERDF Ireland-Wales Programme (INTERREG 4A); with £246,000 allocated to Bangor University. The project also gained the support of numerous industry stakeholders in Wales and Ireland who will sit on the project steering committee, namely: Dublin City Council, Welsh Water, Dulas Ltd., Isle of Anglesey County Council, and Gwynedd Council.   

Publication date: 8 June 2011