Renewable energy consultancy Dulas has completed a 250kW hydroelectric scheme at Welsh Water’s existing Llys y Frân reservoir. 

The scheme, located in a Pembrokeshire country park, controls the flow release to the river Syfynwy to support abstraction at a pumping station located some 15km downstream. Commissioned in September 2017, the scheme is already approaching 1 million kWh of generated electricity, and will power a planned visitors centre, activity hub and boathouse, as well as exporting energy to the National Grid.

The Welsh Government recently announced a new grant scheme that offers 100% relief on business rates for community schemes with a rateable value of up to £50,000. Equally, and as UK Feed-in Tariffs continue to be phased out, existing reservoir sites can offer opportunities for the UK to continue to build out its hydro capacity.

Llys y Frân is a raw water storage reservoir, with a capacity of nearly 10,500Ml. Dulas was appointed EPC contractor by Welsh Water for the project, and was charged with the design, procurement, installation and commissioning of the hydro generator before it was handed over to Welsh Water.

Preliminary work at the site saw Dulas design and install a raw water supply line from one of the discharge regulators along the front of the valve house, requiring the construction of three concrete pillars for support. The main works comprised the installation of a new 250kW hydro turbine and generator, and construction of a new powerhouse building, discharge pipes and an automatic failsafe bypass valve and pipework.

In addition, Dulas added a telemetry function that enables remote control of the new turbine and its bypass system, as well as control of the reservoir spill to within 25mm.

“Dulas has long been a trusted supplier to Welsh Water, and our team has significant experience in the optimisation of existing reservoirs and hydro infrastructure to fully develop their renewable energy potential,” said Crispin Angood, Senior Project Manager at Dulas.

“While the decline of Feed-in Tariffs will present severe challenges for the sector across the UK, schemes like that at Llys y Frân demonstrate the potential of reservoir and water treatment facilities to boost generation by incorporating hydropower technology.”

“Having worked with Dulas on a number of our other operational hydro schemes, we were confident in their ability to maximize energy generation from the reservoir,” said Mike Pedley, Head of Energy at Welsh Water. “The team once again delivered to a very high standard and, as the site is located within a country park, it will serve as a showcase to educate the public on how a hydro scheme operates.”