Historic Corn Mill becomes home to an Archimedean Screw hydropower turbine

It’s been a few years now since the Archimedean screw hydropower turbine was installed and commissioned at Frensham Mill. However, I feel it gives a good insight into what can be achieved at old mill sites. You will see how the owners embraced hydropower and then made improvements to the landscape to increase the existing wildlife and natural habitat of the site.

Mill History:

Frensham Mill is an ancient mill site dating back to at least 1217 when the mill at ‘Feresham’ is mentioned in the Bishop of Winchester’s Rent Rolls. The mill had two mill ponds to ensure that the corn mill had a constant supply of water even if the main river supply ran low; one of which was built on a small Wey tributary carrying runoff from Frensham Great Pond. This large pond feeds into the Wey about half a mile above where the mill was located. The house was re-modelled in 1928 following the demolition of the old mill. At his time a Francis turbine was used to generate electricity. When the Mill was rebuilt in 1876 it was possibly the largest in SW Surrey. The oldest building, the Granary, was renovated in 2012 along with the gardens and the hydro/ heat pump project.

Frensham Mill during the Victorian era  Photo Credit: Frensham Mill

Frensham Mill during the Victorian era Photo Credit: Frensham Mill

The owners wanted to make the most of the renewable energy potential of the old mill race.  The solution was to combine an 11kW Archimedes screw hydropower turbine with a 30kW water source heat pump. Today the mill produces 70kWh of electricity per year and 90kWh of heat, saving over 50 tonnes of CO2 emissions per annum.

Installing the Archimedean Screw hydropower turbine  Photo credit: Mannpower Consulting Ltd

Installing the Archimedean Screw hydropower turbine      Photo credit: Mannpower Consulting Ltd

The Mill had been a barrier to migratory fish for hundreds of years. In order to improve migratory fish passage the Environment Agency specified a fish pass and upgraded stream to link upstream and downstream for the first time in hundreds of years to encourage trout, eels etc. The river banks were restored and the water meadow was reinstated with wild flowers. Around 10% of the river’s flow is directed down the fish pass and into an old ditch to provide a link between upstream and downstream. A series of 10 gravel pools were installed to step down the levels to the mill pond, providing areas of gravel as potential spawning areas.

Archimedean Screw commissioned and generating electricity   Photo Credit: Mannpower Consulting Ltd

Archimedean Screw commissioned and generating electricity Photo Credit: Mannpower Consulting Ltd

The green sand river banks had become severely eroded and were restored with an environmentally friendly planted coir roll system. With the environment utmost in their minds the owners decided to restore the river banks with this system designed to provide an enhanced aquatic habitat both above and below the waterline. Posts were driven into the river bed and pre-planted coir rolls were then placed on top of willow screening and back filled. Today the new banks have become very established.

River bank restoration at Frensham Mill  Photo Credit: Frensham Mill

River bank restoration at Frensham Mill         Photo Credit: Frensham Mill

A survey of the site also found evidence of Serotine & Brown Long Eared bats.  A light proofed area and improved access tiles were installed in the main roof as part of requirements to enhance their habitat. A survey found an established badger trail along the eastern boundary of the site ( that was left undisturbed by the works). Water voles and kingfishers have also been spotted on site.

Photo Credit: Mannpower Consulting Ltd

Completed hydropower project                   Photo Credit: Mannpower Consulting Ltd

And the Archimedean  screw is now set in a garden intended to reflect the spiralling curves of the screw. The water meadow is in the process of restoration with a plan to plant over one acre of wild flowers.

Archimedes set in a garden designed to reflect the spirals of the turbine

Archimedes set in the garden designed to reflect the screw spirals   Photo Credit: Frensham Mill

Once again we see the Ancient power of Archimedes being used for hydropower generation because if it’s fish-friendly credentials. The Archimedean Screw turbine provides a fish-friendly alternative to conventional turbines, ideally suited to low-head (1m-10m) sites, and sites with fish protection issues. Extensive fish passage tests have conclusively demonstrated that the large water chambers and slow rotation of the Archimedean Screw allow fish of all sizes, and debris, safe passage through the turbine. As a result, the Environment Agency has agreed that no screening is required.

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More Rural Development Funding On Offer

A NEW round of funding for rural development projects has opened in County Down.

Farmweek Edition – 20th October 2011

A NEW round of funding for rural development projects has opened in County Down.

In the latest call for applications for monies to help improve the quality of life in rural communities, the Down Rural Area Partnership (DRAP) is inviting local people across the Ards, North Down, Banbridge and Down areas to submit project proposals under the ‘village renewal and development’ theme.

The theme aims to support the development of village plans or fund the updating of existing plans, or to support the physical and environmental regeneration improvements in both large and small villages.

Nearly £4m has already been committed to over 80 projects across the four council areas since the rural development programme began in 2009, with grants ranging from a few hundred pounds to several hundred thousand, all with the aim of improving the quality of life in rural communities.

“This is a wonderful opportunity for progressive groups in our towns and villages to access funding for new ideas to improve and up-grade the environment of these areas. I would hope that all of the eligible towns and villages will take this opportunity with open arms and help make the places where we live better for everyone, resident and visitor alike,” said Councillor Jim Fletcher, Chair of the Partnership.

To apply for rural development funding you must live in a rural location in one of the four Council areas – rural is defined as a settlement with a population of 4,500 or less – or if you live in an urban setting, you must be able to demonstrate that your project will principally benefit a rural area. Farmers, private businesses and social economy enterprises, as well as individuals over the age of 18, can all take advantage of these funding opportunities.

The Rural Development Programme 2007-2013 is part financed by the European Agricultural Fund for Rural Development (EAFRD) and the Department of Agriculture and Rural Development (DARD).

Applications can be made online through the EU Grants website www.eugrants.org or hard copy application forms can be obtained by contacting the Down Rural Area Partnership office on 028 9182 0748. Guidance notes to include eligibility criteria and funding thresholds for the above measure are available at  www.downruralareapartnership.com. The closing date for applications is Wednesday 7th December 2011 at 4.00pm.

Source: Farmweek