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A controversial project to build a hydropower plant on the River Thames has received planning permission, despite fierce opposition from local residents because of its size and noise.
The planned development by community group Teddington and Ham Hydro will install three Archimedes screws at a weir in Teddington to generate an annual average output of 1.6GWh of electricity for the grid. Construction will begin next summer, with commissioning due for summer 2018.
However the project has been slammed for using “amateur” developers, causing excessive noise during operation and increasing the risk of flooding. A petition against the local council’s decision to build the plant has so far received 1,300 signatures and a judicial review of the plant is pending,
David DeChambeau, director of Southeast Power Engineering (SEP), was brought in to manage the project six months ago, and help with the technical design. He said that Teddington and Ham Hydro had initially engaged with “other amateur hydropower developers that were working with manufacturers in Europe that just build a product and sell it”. The off-the-shelf nature of these products, he said, was unsuitable for the conditions at the Teddington weir site, which is tidal for 16 hours every day. Noise from the turbines could be heard up to 500m away because the total head is lowered as the lower water level rises. Local flooding regulations also mean the design of the plant has to be modified so that it can be raised out of the water.
DeChambeau said: “They had to put a long extension tube on the design to put the generator and gearbox well above the flood level. As a result they had a system that was enormous and opposed by everybody.”
He said noise will be reduced through changes to the shape and size of the blades, “soundproofed housing”, the inclusion of a direct online motor starter so generators run quieter and cooler, and a possible change to the trough design. He added that it is possible to make fixed-screw designs quiet, with an appropriate operating procedure in place.
DeChambeau said the developer will continue to meet with local groups in an attempt to “unruffle all those feathers”.
Lacy Curtis-Ward, chief executive of the Lensbury, a nearby hotel and leisure centre, opposes the plans. Curtis-Ward said: “The Lensbury club, Teddington society and other residents’ associations support hydropower in principle but not the application and design as it stands now.”
SEP has previously installed two 40-tonne Archimedes screws at Romney Weir, which provides power for Windsor Castle. The turbines had to create no more than 35dB so the operating noise could not be heard at a nearby residence.