October update on Nethermills Hydro Scheme



Since the corn mill at Nethermills was demolished in the 1950s at least 20 Gigawatt hours of useable energy have passed over the weirs in the centre of Ayr.  The Energy Agency commissioned a hydrological study in 2015 followed by a feasibility and design study by Mann Power Hydro Ltd. The result is the current construction project by Energy Agency Renewables Ltd, with TLS Renewable Consulting Ltd as project manager and Bailey Contracts Ltd as civils contractor.

The fish-friendly, 4-metre-diameter Archimedes screw will generate up to 85 kilowatts and a total of 320 megawatt hours in a typical year. Revenue from feed-in tariff and electricity sales will be used to maintain the system, the surplus supporting the fuel-poverty-and-carbon-reducing activities of the non-profit Energy Agency. 

Features of the scheme:

A hydro scheme providing 100% green electricity is in keeping with South Ayrshire Council’s long-term development plan to regenerate the riverside area in a sustainable way and contribute towards the Council’s Carbon Management Plan

Local benefits include a source of carbon-free electricity and funds for local projects by the Energy Agency

The turbine will be a local attraction on the River Ayr Way, displaying information on renewable energy generation to passers by

The scheme design, including new smolt chutes and eel passes, will assist the passage of migratory salmon and eels and the installation of a fish counter in the existing fish pass will benefit the management of the River Ayr catchment fishery

The scheme will prevent the emission of an estimated 147 tonnes of CO2-equivalent greenhouse gas annually and continue to generate green energy for many decades, just as the watermills did from the 13th to 20th centuries

Where are we now? (Oct 21)

Construction work is around 78% complete. The cofferdam to provide a watertight enclosure so the works can be carried out has been in place since April 2021. The structure and foundations have been laid to support the turbine screw and powerhouse. The path of the cable from the turbine house to the grid connection point has been finalised and relevant wayleave consents agreed. Work is ongoing this week to lay the electric cable between the powerhouse and the grid connection point in Ayrshire College.

 The temporary fish pass that was constructed specially during the first part of the works has now been removed and will be used at another site by Ayrshire Rivers Trust.

This is our Archimedes Screw turbine being built in Belgium. It is now due to arrive with us on Wednesday 10th November. The turbine screw, generator and other heavy parts will be lifted by crane from the river bank into the newly constructed powerhouse on the river from Wednesday to Friday that week, ending with the roof of the powerhouse being lifted into place. 

Regular  update meetings have taken place with Marine Scotland Science and their contractor Fishtek, who are installing a fish counter and camera, and coordinating this with our civils contractor, Baileys Construction. The first stage of equipment was scheduled for installation in the third week of October but has now been delayed until mid November,  weather/river level permitting. The final work will need to wait until the powerhouse is complete, weatherproof and the power supply in place, which is likely to be mid-to-late December