The Benefits of an Archimedean Screw Hydropower Turbine

Energy generated from flowing water resources gives the highest efficiency rating of all sustainable energy sources!

The Archimedean Screw hydropower turbine is a new application of an ancient technology. For thousands of years the screw was used to pump water up from rivers or streams to irrigate farm land. Now, using the same system in reverse the Archimedean Screw is being used to harness the power of the water to generate hydroelectricity. Hydropower installations generate renewable energy from flowing water resources. This could be from a lake, river, stream or from old mill sites.

Archimedean Screw turbines offer a hydropower solution that is:

  • Commercially attractive & cost effective
  • Practical & efficient
  • Fish-friendly
  • Easy implementation in existing situations (no civil constuction work)
  • Insensitive to clogging
  • Low maintenance costs
  • Improvement of water quality
  • Self regulating to changing water flow
  • Long life time
  • Scaleable & bespoke

This technology lets you harness the power of the water that flows over or through your land. Once your turbine has been commissioned and connected to the grid you’ll be generating hydro-electric power 24 hours a day, seven days a week. Whether the power is for your own property, to sell back to the grid or a combination of both, the Archimedean Screw will likely pay for itself several times over in the course of its operational lifetime (depending on the feed-in tariffs available) . And what’s more these turbines can be scaled to suit all needs – from small domestic applications to huge industrial installations.

Overview of an Archimedean Screw ~ Photo Credit: Landustrie

Overview of an Archimedean Screw ~ Photo Credit: Landustrie

If you’re not sure whether your site is suitable for an Archimedean Screw we’ve put together a checklist of requirements for your reference. Archimedean Screw turbines offer a uniquely flexible hydropower solution that can be installed at sites with a broad range of topographical features. But there are some fundamental requirements your land will need if a project can go ahead.

The basic requirements required for an Archimedean Screw hydro turbine are:

  • A water source with a drop of at least 1.5 metres
  • Access rights to that water source
  • A grid hook-up point less than 500 metres from the water source – unless the Screw is being used for ‘off grid’ generation only.

If your site satisfies these criteria then there’s every chance you will be able to harness the power of the waterway to generate hydroelectricity. And Eco Evolution will be delighted to pilot your scheme all the way through to delivery.

If you’re still not sure whether your site is right for an Archimedean Screw turbine, get in touch and we will be happy to discuss the specifications and requirements in greater depth.

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 🙂 🙂

A look back at 2014 – the power of water!

The blog has been quite of late so now its time to get back into the swing of things.  And what better way than to look back on some of the most memorable posts of 2014.  While looking back through the posts over the past few days it has stuck  me just how busy we were in the last year!

We have had to spend a huge percentage of the year traveling and working in the UK due to the lack of support mechanisms and action on microgeneration here in Ireland. In December ESBCS withdrew their export tariff scheme to new microgeneration customers which now means there is no financial incentive in this country for microgeneration as ESBCS were the only supplier offering such a tariff. Contrast this to the ROCs system in NI and the REFIT scheme in Britain, both these schemes pay for actual generation not just what is exported, there is a smaller top-up payment for export. On the brighter side we got the opportunity to travel through the most scenic countryside to visit and work on beautiful rivers and old mills.

Working in the great outdoors

Working in the great outdoors

Penllergare Valley Woods.

Almost a year ago to the day we visited Penllergare Valley Woods located on the northern fringe of Swansea. It was once a famous gentry estate and home to John Dillwyn Llewelyn, the notable 19-century horticulturalist, philanthropist and pioneering photographer. The development of the hydropower scheme in Penllergare Valley Woods will generate sufficient power to meet the needs of the sites new visitor centre and excess sold to the National Grid, raising an expected £10,000 per year for the trust. The Archimedean Screw with a length of 11m and a capacity of 2880 m3/h is situated next to the waterfall at Penllergare Valley Woods.

Archimedean Screw with ell pass running along side

Archimedean Screw with ell pass running along side

 Osney Lock.

Osney Lock Hydro was the first community-owned hydro scheme to be built on the Thames. There was extraordinary support shown by local people towards the project. The Osney Lock Hydro share offer raised over £500,000 in just four weeks. Without this swift and significant support the project would not have been able to go ahead. Over 40% of the investment came from within a mile of the project and 4 out of 5 investors live in Oxfordshire.  On Tuesday 25th March at midday the dreams of the local residents came to life when a 4.35m-long, four-bladed Archimedean screw was installed at Osney Lock.

 

Osney lock hydro installation

 Mapledurham Watermill

The watermill is the last working corn and grist watermill on the River Thames and is still producing high-quality stone-ground flour today.  An Archimedean Screw hydro turbine was designed and installed in 2011 to replace the original turbine that had fallen into disrepair.   The 7.27 m Open Compact Archimedean Screw has a capacity of 5,000l/s and a predicted output of 99.95kW. It is estimated that it will save 221 tonnes of CO2 per annum. Over the course of a year, the screw will produce approximately 500,000kWh of renewable electricity which is being bought by Marks and Spencer via the national grid. The electricity generated is sufficient to power one of its stores.

Archimedean Screw

Archimedean Screw

The mill produces stone-ground flour using a waterwheel. Wholemeal and white flour, bran, semolina and Millers Mix, a blended combination bran and semolina, are all produced at the mill.  When the sale of the electricity has covered the cost of the turbine, the profits will go towards renovating the mill and its outbuildings to how it was 200 years ago. The new water wheel is the exact structural copy of the existing water wheel and is made out of oak which was sourced from the Mapledurham Estate.

New water wheel at Mapledurham

 Cragside House

Cragside was the first house in the world to be lit by hydroelectricity. On the 9th April, a century and a half  after the first hydropower installation at Cragside House a new hydropower turbine arrived onsite. A 21st century, 17m long Archimedean Screw rated at 12kW and weighing several tonnes was craned into position at the southern end of Tumbleton lake and  will produce enough energy to re-light the house just like Lord Armstrong did.

 

17m long Archimedean Screw insitu

17m long Archimedean Screw insitu

Osbaston

The project consists of two 3.6m diameter Archimedes Screw hydropower  turbines. The turbines were designed to rotate at a speed of 28rpm, which produce a maximum power output of 150kW.  The estimated annual power output is 670,000kWh enough electricity to power over 150 homes and gives an estimated annual CO2 saving of 288 tonnes. A small percentage of the power generated is used to power the owners home and the remainder is sold to the National Grid. The fish pass and hydropower scheme was offically opened in 2009.

Wordless Wednesday ~ the power of water!

 Sowton Weir

Sowton Mill stands on the  River Teign in Devon and has been using hydro power for over 400 years, initially to mill corn and then, from the 1950s, to generate electricity.  In the 1980s a 16kW crossflow turbine was installed which was the U.K.s smallest electricity contributor to the National Grid. To improve the power generation and aid fish migration a decision was made to install the fish-friendly Archimedean Screw hydro turbine. Sowton hydropower scheme was developed by a private client to provide a renewable source of electricity to the property on site with all excess power sold to the National Grid.

95kW Archimedean Screw Hydro turbine

95kW Archimedean Screw Hydro turbine

 Tours and Shows

One of the most exciting memories of 2014 was visiting the IFAT show in Munich and continuing on to visit some Archimedes Screw installations in Munich, Czech Republic and The Netherlands. IFAT 2014 is the world´s leading exhibition of innovation solutions for environmental technology. Climate change, rising raw material prices, an increasing number of mega-cities and advancing industrialization in emerging countries  boost the demand for products and services that address environmental and climate challenges. With growing pressures on European countries to reverse years of environmental damage and to find more integrated pollution control techniques, the potential is limitless.

 

Frank at IFAT 2014

Frank at IFAT 2014

There are many more projects both here and in the UK at various stages of build which I hope to blog about throughout 2015. The projects mentioned are a taste of what community groups, home owners and businesses have achieved in their desire to harness the power of the river to generate green electricity. On our trips around Ireland with the Mills and Millers of Ireland we met several mill owners and enthusiasts who, like us are promoting the benefits of hydropower and encourage and assist in the preservation of old mills which are part of our Industrial, architectural landscape heritage.

We will continue to fight for microgeneration incentives because after all every person or household in the country that pays an electricity bill also pays a PSO. So  it is a little unfair that the ordinary man in the street who pays the bulk of this PSO does not benefit from it in the form of any incentive that would help him to install his own microgeneration.

 

 

 

Fish-friendly hydropower at Sowton Weir

Sowton Mill stands on the  River Teign in Devon and has been using hydro power for over 400 years, initially to mill corn and then, from the 1950s, to generate electricity.  In the 1980s a 16kW crossflow turbine was installed which was the U.K.s smallest electricity contributor to the National Grid. To improve the power generation and aid fish migration a decision was made to install the fish-friendly Archimedean Screw hydro turbine. Sowton hydropower scheme was developed by a private client to provide a renewable source of electricity to the property on site with all excess power sold to the National Grid.

95kW Archimedean Screw Hydro turbine

95kW Archimedean Screw Hydropower turbine

Mann Power Consulting Ltd.,designed the Open Compact Archimedean Screw for this particular site which was manufactured by Landustrie in Holland.  An Open Compact is a self-supporting U-shaped steel construction minimising necessary civil work on site. The generator unit is an integral part of the construction, easily accessible via a weatherproof, hinged generator cover. The length and diameter of an Archimedean Screw will be dictated by the parameters of the particular site and are finished in the colour of your choice. All Archimedean Screws are manufactured as bespoke installations. Rated at 95kW it is expected to save in excess of 165 tonnes of Carbon Dioxide (C02) annually. The predicted annual output is 368,000kWh per year.

Fish-friendly hydropower at Sowton Weir

Closed compact Archimedean Screw

Improvements were also made to the fish pass at the nearby Weir.  These measures will make it easier for fish to move upstream and will add to the understanding of their migration patterns. The Archimedes  hydropower installation has improved the fisheries ecology of the river Teign by allowing more juvenile salmon and sea trout reach the sea. The improved fish pass at the weir means more salmon and sea trout can reach spawning grounds on the upper Teign. An automatic fish counter was also installed to count the fish numbers and species using the pass. This provides invaluable information for the Environment Agency and the Teign fishing association.

Sowton Weir

Sowton Weir

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.

If you are the owner of an old mill site or a potential hydro site or are a community group interested in developing a hydro project for community use please contact us here.