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.

To keep up to date with our hydropower projects or to find out more about hydropower you can  find us on Facebook or Twitter or Google+ . To talk to one of our engineers contact us here

A return visit to Penllergare Valley Woods hydropower scheme

On our recent trip to the London we decided to bring the car and take the ferry to Fishguard to visit some of the hydropower sites we have worked on over the last year. Our first port of call was a visit to Penllergare Valley Woods, a picturesque landscape hidden away in a steep valley just a stone’s throw, yet a world away, from the M4 in north Swansea.

The Archimedean Screw along side the man made waterfall

The Archimedean Screw along side the man made waterfall

As part of the upgrade and restoration of Penllergare Valley Woods a 30kW Archimedean Screw Hydro Turbine was installed to ensure a sustainable future for Penllergare Valley. A little over a year ago the hydropower scheme was commissioned and is now generating clean green electricity to power the new visitor centre with excess being sold back to the national grid. The Archimedean Screw with a length of 11m and a capacity of 2880 m3/h is situated next to the waterfall. The enclosed compact design was the preferred design of screw for this particular site as the design minimised the installation cost and doesn’t intrude on the existing landscape.

30kW Archimedean Screw

30kW Archimedean Screw

With its lakes and waterfalls, terraces, panoramic views, exotic trees and shrubs, this forgotten Victorian paradise is being slowly restored and brought back to life by the Penllergare Trust. Penllergare Valley Woods was once a famous gentry estate and home to John Dillwyn Llewelyn, the notable 19-century horticulturalist, philanthropist and pioneering photographer. It is Llewelyn’s design, vision and influence behind the picturesque and romantic landscapes of the park.

A return visit to Penllergare Valley Woods Hydropower schemePenllergare Valley Woods is a place where you can enjoy the sound of birds, delight in the profusion of wild flowers, discover evidence of exotic plantings and uncover for yourself the hidden features of a grand design. Wildlife research carried out by Swansea Council has found the estate is very significant for amphibians and acts as a “corridor” for animals to thrive and move about.

One of the many ancient Rhododendrons in full bloom

One of the many ancient Rhododendrons in full bloom

Through hard work, persistence and community spirit by local volunteers and with the financial support of sponsors and the Friends of Penllergare membership scheme, they have been working hard over the last decade or so to maintain and to restore the Penllergare landscape to the romantic style shown in the photographs of John Dillwyn Llewelyn who created it. The rhododendrons, the legacy of the ‘plant hunting’ Dillwyn Llewlyn family in the 19th centurywere a popular sight along every walk way.
Beautiful woodland walk

Beautiful woodland walk

It was obvious throughout our visit that volunteers had been working hard replanting specimen trees and ornamental shrubberies which had been lost from the existing landscape. They have also been thinning and managing areas of dense trees and shrub to reopen historic views.
A return visit to Penllergare Valley Woods hydropower scheme
Visitors can enjoy over 12km of walks including along the Carriage Drive to the now demolished former home of the Dillwyn Llewelyn family, and also down into the gorge where the family created the upper lake with a stunning man made waterfall. Paths and tracks lead on down alongside the afon Llan as it meanders its way to Fforest fach.
A return visit to Penllergare Valley Woods Hydropower scheme
A return visit to Penllergare Valley Woods Hydropower schemeThroughout the last few years the upper lake has been de-silted, and steps, terraces, the stone-arched Llewelyn bridge, waterfalls and cascades have been repaired and restored to reinstate the picturesque and romantic design.
Some of the many ancient trees

Some of the many ancient trees

A return visit to Penllergare Valley Woods hydropower schemeUsing photographic evidence from the 19th century, the old stone bridge was recreated in the traditional style by local stonemasons.

The original stone bridge

The recreated stone bridge

After walking for hours and checking out the Archimedean Screw we spent some time browsing through the information books and leaflets in the visitor centre and then enjoyed a cup of coffee at the small cafe which has stunning views from the cafe terrace to the upper lake. If you’re ever in the area it is well worth a visit. Dogs are also welcome :) :)

Mills & Millers of Ireland Summer Event –Saturday 4th July 2015

The Society of Mills and Millers of Ireland was launched in 2001 to encourage and assist in the preservation and appreciation of mills as part of our industrial, architectural and landscape heritage. There are hundreds of mills and mill sites spread across the country and while many are beautifully refurbished or put to good use, there are also many others which could be restored or renovated while preserving their traditional context. The society aims to promote interest and awareness in this aspect of Ireland’s industrial heritage by building up knowledge and expertise in areas such as law, architecture, renewable energy and manufacturing and making information available through publications, lectures and events.

Old Mill Coffee Shop, Upperlands

Old Mill Coffee Shop, Upperlands

The Old Mill Coffee Shop is based in the heart of the Historic Linen Village of Upperlands and opened in March 2013 it is a restored beetling mill bursting with character. The beetling mill is situated beside the coffee shop, this is said to be the only commercial beetling mill in the world!

Beetling Mills Coffee Shop

This year’s Summer event is a one day event taking place on the 04th July in the lovely countryside of County Derry. It’s going to be a very active day with visits to several local mills, a tour of the Beetling Mill in Upperlands and a talk by Mr. Douglas Lamont followed by a visit to the Clark family. After lunch the group will visit Barney and Michael Lagan, Upperlands. Take a look at the timetable to see the list of interesting events that have been organised.

Mills & Millers of Ireland Summer event 2015

Mills & Millers of Ireland Summer event 2015

Fee for the day including refreshments and lunch: €25 per person.

To book:
(A) Download a booking form here and return to: Hon. Treasurer Mr. John Delaney, Ballingard Road, Roscommon, County Roscommon (Cheques payable to MMOI)

(B) Pay for the event using the PayPal secure online payment option button. Please select the number of places from the drop down menu.

Telephone enquiries: S. Bourke

Hydropower – the world’s oldest method of harnessing clean power

Greater awareness of the potential damage to the planet from global warming has lead governments and multinational organisations to take measures to mitigate the impacts of human activity on the climate. With little or no CO2 and other greenhouse gas emissions and high energy payback, hydropower supports clean development and is recognised as being fully renewable and sustainable.

Hydropower -

Hydropower – the world’s oldest method of harnessing clean power

 Some interesting hydropower  facts:

  • Hydropower is the world’s leading renewable energy resource and the oldest method of harnessing clean power – the first waterwheels were used over 2,000 years ago
  • It currently produces around 17% of the world’s electricity and 90% of the world’s renewable power
  • Twenty-five countries depend on hydropower  for 90% of their electricity
  • Less than one third of the world’s practical hydro capacity has been developed
  • Hydropower beats all other electricity generating technologies with a pay-back ratio of 300 (energy produced/energy to produce) – this is ten times more than oil-fired power stations.
  • There are no direct CO 2 emissions from hydro projects.
Hydropower -

The first waterwheels were used over 2,000 years ago

  • Small hydro schemes have minimum visual impact on their surrounding environment.
  • Hydropower, after 150 years as an electricity generating source, is still one of the most inexpensive ways to generate power
  • Most large hydro stations have dams but thousands of small hydro stations don’t – they are ‘run-of-river’ schemes and make a minimal impact on the environment
  • Hydro is the only renewable technology that can be used to store large quantities of energy in a clean environmentally-friendly way. This is done by reservoir storage and pumped storage schemes.
  • Hydro installations can have a useful life of over 100 years – many such plants are in existence worldwide
  • A modern hydro turbine generator can convert over 90% of the energy in the available water into electricity. This is more efficient than any other form of generation.
Shane's Castle Archimedes Screw Installation - largest single screw ever to be manufactured

Shane’s Castle Archimedes Screw Installation NI- largest single screw ever to be manufactured

Hydropower is a flexible technology, proven, improved and refined over many years, yet its site-specific features make it highly innovatory in application, which makes use of a wide range of available resource – large or small, storage or run-of-river, and including tidal range, canals and even water treatment works. It is still one of the most inexpensive ways to generate power, playing an important role in our electricity system stability.

If you are the owner of an old mill site or a potential hydro site, would like to refurbish or replace a water wheel or a community group interested in developing a hydro project for community use we can help. Just contact us here and we will answer all queries and help you every step of the way with your proposed project.




Chooseday’s Choice! ~ Wood Fuel or Fossil Fuel?

Where does YOUR  energy go?

Fossil fuels are derivatives of plant and animal fossils that are million of years old. These are primarily formed from the remains of the decayed plants and animals. The three fuel sources coal, natural gas and oil help to meet the energy and electricity demands of today’s world.  Fossil fuels are non-renewable energy resources. Their supply is limited so they will eventually run out. Fossil fuels do not renew themselves, while fuels such as wood can be renewed endlessly.

Pollution is a major disadvantage that is formed due to fossil fuels as they release carbon dioxide when they burn, which adds to the greenhouse effect and increases global warming.  Coal and oil release sulphor  dioxide gas when they burn, which causes breathing problems for living creatures and contributes to acid rain.


You Choose!

You Choose - Wood Fuel or Fossil Fuel

You Choose – Wood Fuel or Fossil Fuel

Wood Fuel:

Using wood fuel instead of peat, coal and gas to heat our homes is a sustainable choice, and makes a positive contribution to the environment. Wood is ‘CO2 neutral’, the amount of CO2 wood releases during burning is equal to that which is absorbed during growth. In contrast, burning fossil fuels releases the global warming gas carbon dioxide, as well as other damaging pollutants. Wood fuel also takes just 5-20 years to grow, whereas peat and coal were formed over hundreds of thousands of years.

WFQA – Wood Fuel Quality Assurance:

wfqaThe Wood Fuel Quality Assurance (WFQA) scheme provides a simple but reliable way for consumers to purchase quality wood fuels that are accurately described, meet the supplier’s stated product specifications, and are produced in compliance with EUTR (EU Timber Regulation) ensuring sustainably produced woodfuels.


Modern, highly efficient stoves and boilers make wood fuel a practical and sustainable option for today’s lifestyle!