Trews Weir Hydro

Trews Weir Hydro Project

Last year we were given the go-ahead by Exeter City Council to look into the viability of a hydro project on the River Exe at Trews Weir. The map to the right gives you an idea of where this is in relation to the city. We appreciated the help from our members and supporters. Thank you.


Initial Feasibility Report

Hydromatch has now completed its feasibility study of hydro-electric power at Trews Weir. They completed a site survey, investigating the flow and head of the weir and then provided performance modelling with an outline design. The Environment Agency provided needed information and Western Power Distribution (WPD) were consulted with regards to possible grid connections. There would need to be a new substation built next to the existing substation but a grid connection is possible. This is good news as it means we would be able to export the hydro power to the grid if there is not viable local demand. One possible siting would be alongside the fish and eel pass that was built in 2015 and we are now investigating other possibilities too.

Two turbine types being considered are the Archimedes screw (explained below) and the Kaplan turbine. Different system configurations are being compared regarding generation potential, income and installation costs.

Our community hydro finance model has shown options are financially viable, so we’ve had our first meeting with the EA and we’ve started making the pre-planning application to allow ECOE to obtain a license from the Environment Agency.

We’ve started talking to river users and researching the potential impact a hydro scheme might have on the river and residents living nearby – both animals and people! We will be taking into account the concerns of all river users – anglers (coarse fishing and salmon), kayakers, boat users. Engaging with the local community and finding out their concerns and finding ways of addressing them will be a very important part of the development of the project. Its an important element of the EA investigation into our application for an abstraction license that we have addressed any concerns of the river users and the local community.


The Archimedes Screw Turbine

The ‘Archimedes screw‘ turbine is where water is fed into the top of the screw, forcing it to rotate as the water falls through it. The rotation of the shaft generates electricity. This a great way of generating electricity, as it generally has minimal impact on the environment.

The Archimedean screw hydro turbine is relatively new in the field of renewables, having previously been used as a simple water pump with no electricity-generating capacity. River Dart Countrypark has a working Archimedean screw turbine and examples of community owned hydroelectric schemes include Settle Hydro (in North Yorkshire) and Torrs Hydro (in Derbyshire).

Trews Weir