Mendip Mills energy makeover
Giving historic water mills a contemporary purpose generating electrical and thermal energy
Project duration: November 2003 to August 2004
The aim of this project was to give 15 historic water mills in Mendip a contemporary purpose, primarily by installing systems for generating electrical and thermal energy from the water source at each site. The project also aimed to facilitate energy efficiency improvements at the mill houses and associated business premises.
CSE worked with Hydro Generation Ltd to assess the technical and financial feasibility for electricity generation at each mill site. A significant part of the feasibility process involved consultation with local community stakeholders to establish support for the project as a whole, examine incentives and barriers to the set up and management of the community energy fund, and to set parameters for use of the fund.
Preliminary talks with the Environment Agency were held to help ensure that planned hydroelectric schemes did not negatively impact local flora and fauna and complied with the regulatory framework for water abstraction and impoundment.
Analysis of the data from Home Energy Checks for 11 of the mills showed that they were 'hard-to-treat' homes, in that they all had solid walls. Excluding wall insulation, the potential for energy saving from standard measures was on average only 9%, and for six of the mills was 5% or less.
The study showed that several of the sites had very promising potential for installing modern hydropower units. Three of the sites had potential for more than 30kW, while a further seven had a potential for 5-10kW. The simple payback times for these ten sites, allowing for a household grant from Clear Skies, were all less than 18 years, with four of less than ten years. This was based on a conservative estimate of future prices for green electricity. If these ten sites were to proceed to implementation, this would represent a total installed capacity of 147kW, an average annual energy output of about 600,000kWh, and an annual saving in carbon dioxide emissions of about 260 tonnes.
The approach of establishing the Mendip Power Group, in order to share information and provide collective representation to funders, regulators and utilities, proved to be very successful. This was due in no small part to the energy and enthusiasm of the members of the group. Also, carrying out 15 surveys at one time led to cost savings in the feasibility studies and time savings in dealing with the Environment Agency and in dealing with suppliers for quotations.
In March 2004, the MPG, with support from CSE, secured £50,000 of funding from the SWEB Green Energy Fund to support the installation of hydropower systems at the ten sites. It is expected that the three largest schemes will be completed in 2005, namely Tellisford Mill (31kW), Stowford Mill (37kW) and Shawford Mill (31kW).
It is hoped that seven more of the mills will proceed with installations during 2006. Abstraction licences will be applied for once the initial three sites have been successfully installed. A total installed capacity of 48.1kW would result from the seven sites, which include: Jackdaws Iron Works (10kW), Glencot House (5.8kW), Burcott Mill (5.2kW), Bleadney Mill (5.4kW), Coleford Mill (6.6kW), Old Mill (5.2kW) and Farrants Mill (9.9kW).