Trews Weir Hydro

Trews Weir Hydro Project

As of June 2017, we have been 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’d like to thank again all our members and supporters who wrote to their local councillor of the benefits of this project. Without your help we might not have been able to get this project off the ground and it helped the Council understand the social value of such renewable projects, in addition to the economic benefits.

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 outline design. The Environment Agency provided needed information and Western Power Distribution (WPD) were consulted with regards possible grid connections. There would need to be a new sub-station 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. The likely siting would be alongside the fish and eel pass that was built in 2015.

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.

The next stage includes checking the financial viability in a community energy finance model and then if at this stage its financially viable, we’ll be talking further with the EA and making the pre-planning application to allow ECOE to obtain a license from the Environment Agency.

We’ve started talking to river users and research 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 is 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