Laser cut waterwheel designed and installed to generate electricity.

The waterwheel is an ancient device that uses flowing or falling water to create power by means of a set of paddles or buckets mounted around a wheel. A waterwheel consists of a large wooden or metal wheel, with a number of paddles or buckets  arranged on the outside rim forming the driving surface. Most commonly, the wheel is mounted vertically on a horizontal axle. Prior uses of water wheels include milling flour in gristmills and grinding wood into pulp for paper making, but other uses include hammering wrought iron, machining, ore crushing and pounding fibre for use in the manufacture of cloth.

Traditional waterwheel

Traditional waterwheel

On occasion the old water wheel is still insitu and can be refurbished but in many cases the wheel has been removed and sadly sold for scrap metal value or taken apart to be kept as keepsakes or used as garden ornaments. If a mill has a vacant wheel pit it is possible to construct a water wheel which is aesthetically pleasing and bring the character back to the old mill. On some old mill sites access to the wheel pit is confined and in cases like this the preferred option is a bespoke laser cut waterwheel.

Components of a laser cut waterwheel

The spokes, rims and buckets are all fabricated from pre-galvanised sheet finished with polyester powder coating. These lightweight components were easily and rapidly assembled using stainless steel nuts and bolts without the need for welding or any special tools on site.

Laser cut waterwheel designed and installed to generate electricity.

The waterwheel arrives flat packed on site and during construction, the waterwheel components can be lifted in place without the need for heavy lifting machinery, reducing installation time and health and safety risks. This also allows assembly in areas with limited access e.g. rural areas with narrow roads.

Waterwheel instalied and generating electricity

Advantages of waterwheels

Waterwheels are widely regarded as being rather inefficient compared with turbines. This is not necessarily the case as studies have shown that waterwheel efficiency can be in excess of 80% for Overshot waterwheels and 75% for Breast-shot waterwheels [Muller 2004]. This in combination with highly respectable part-flow performance and lack of fine intake screening requirements can often result in very worthwhile overall energy capture so are still a viable proposition for producing electricity for domestic purposes. They are simple to control and aesthetically pleasing. Although they run relatively slowly and require a high ratio gearbox to drive a generator, for low powers – say below 5kW – and heads below 3m, they are worth considering.

Water wheels are also safe for the passage of fish.

  • Output reduction due to screen blockages is avoided since fine intake screens are not required.
  • Part-flow performance of waterwheels can be very good without requiring complex control systems.
  • Often minimal building work is required, particularly at former watermills if there is a vacant wheel pit.
  • Waterwheels have obvious aesthetic benefits over turbines and provide an excellent attraction at sites where visitors are encouraged.

To keep up to date with our hydropower projects or to find out more about hydropower you can  find us on Facebook or Twitter and  Google+ . To talk to one of our engineers contact us hereWe offer a turnkey service if required and would be happy to discuss your requirements.

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.




Mapledurham Watermill ~ the last working cornmill on the Thames.

Over the last couple of weeks Frank has been in the UK commissioning various hydropower schemes around the country. During this time he also carried out some maintenance work on the Archimedean Screw Hydro Turbine which was recently installed  at the award winning Mapledurham watermill to generate clean green elcetricity which is being sold to the national grid. The watermill is the last working corn and grist watermill on the River Thames and is still producing high-quality stone-ground flour today.


Mapledurham Watermill with working waterwheel and Archimedean Screw

A mill was already situated at Mapledurham at the time of the Domesday Survey. The central section of the current mill building dates back to the 15th century. Originally the mill had a single water wheel, on the river side of the building. The mill was increased in size in the 1670s, and a leat was constructed to drive a second water wheel on the village side. It is this second wheel which is still in use today. At its busiest it employed five people, and the miller was prosperous enough to rent the finest house in the village street.

Mapledurham Watermill - last working watermill

In 1690 the mill was leased to James Web for the sum of £60 per year. Around 1700 he expanded the mill again, to allow him to install the equipment to produce the refined flour that was becoming popular. His son Daniel Webb took over from him in 1726 at a rent of £100. Thomas Atrum took over the mill at a rent of £150 p.a. in 1747, which was raised to £205 in 1776. In 1777 a barn was added on the mill island, and a wharf built to allow the mill to supply flour to the London market by barge. However by 1784 Thomas Atrum was bankrupt.

Mapledurham watermill

Mapledurham WatermillThe mill continued to flourish, and as late as 1823 plans were drawn up to rebuild the mill in classical style. The advent of cheap imported flour from North America damaged the mill’s prosperity, but it remained in use until just after the Second World War. It was restored and brought back into use in 1980.


Original Waterwheel at Mapledurham watermill built in 1670

Built in 1670 the waterwheel at Mapledurham watermill still grinds flour today

Over the years some of the paddles of the existing original wheel were beginning to show their age so these paddles were replaced so as to extend the life of the waterwheel and to allow it to continue to grind the flour. A new waterwheel is currently under construction and it is hoped that it will be installed during the Summer. The main reason for replacing the wheel is the appearance of a number of splits in the wheels framework and also many of the joints are showing signs of decay and movement. The wheel will be as exact structural copy of the existing one and will be made out of oak which has been sourced from the Mapledurham Estate.

The new oak waterwheel in construction ~ Photo Credit:

The new oak waterwheel in construction ~ Photo Credit:

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. The Mapledurham estate also produces milk for Marks and Spencer. 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.

Mapledurham Watermill

Parts of the original machinery from the watermill

On our return visit to the watermill this week we were delighted and surprised to see that the new wheel had been installed.

The mill is located in the grounds of Mapledurham House, and like the house is open to visitors on weekends and bank holiday afternoons from April to September. The water mill is normally working on opening days, and visitors can visit both main floors of the mill, and see  its operation.

The watermill is perhaps best known for its starring role in the 1976 film, The Eagle Has Landed, where the mill leat is the scene of the dramatic rescue of a local girl by a German paratrooper that results in the unmasking and ultimate failure of the raid. It is also the backdrop in the image on the cover of Black Sabbath (album), by the band of the same name.

 If you’re interested in getting an existing water wheel refurbished or own the site of an old mill that has the possibility of reinstating a water wheel and would like more information please contact us here.



Hydropower generation at Brett’s Sion Mill on the river Nore

Bretts Mill on the River Nore, dates back to the 14th Century. The mill has been in the Brett family since the 1800s and the present owner John is carrying on a proud tradition, except that his operation, making the finest native Irish hardwood flooring, uses hydroelectric and biomass energy on-site, with surplus exported to the national grid. The clean production of electricity at Brett’s saves approximately 5,000 tonnes of Carbon Dioxide (CO2) annually.

Bretts Sion Mills

The hydro turbine generating clean green energy

The undershot mill wheel, the oldest one of its type continually in use in Ireland  is a satisfactory solution to low-head hydropower in terms of construction, reliability and ease of maintenance. In addition, it is benign to fish movements and provides excellent aeration which is necessary for life in the river.  The paddles of the waterwheel are flat and are simply dragged round by the flowing water.

Bretts Sion Mills

Undershot waterwheel one of the oldest in continuous use in Ireland

By 1850, Ireland had around 6,400 watermills, according to the EU-funded SPLASH (Spatial Plans and Local Arrangement for Small Hydro) report. Nearly all of the old watermills have long since fallen into disuse, but the potential they represent is still there. Cost is a factor, but the report emphasises that small scale hydro schemes are a secure and reliable form of energy that should be used as part of the drive to promote renewable energy.

Old mill sites are ideal sites for hydropower because  in most cases the original structures are still insitu which in turn cuts down on the cost of civil work which greatly reduces the cost of a new install. The Irish Hydropower Association estimates, for example, that up to 600 old mill sites around the country could be redeveloped into hydropower generation sites.

Bretts Sion Mills

Kilkenny hurley on display

On the day we visited the mill John discovered that we were from Wexford and took great pride in showing us the gigantic hurley he had on display in one of his many workshops.  He makes the hurleys for the Kilkenny team and in his words “this is why they are winners” !! 🙂

A labour of love ~ restoring Howsham Mill back to its Gothic Georgian glory!

Howsham  Mill is a Grade II listed building, built in 1755 and attributed to the architect, John Carr of York.  It was both a folly and a working grist mill on the Howsham Hall estate.  The mill was powered by a breastshot waterwheel connected by a gear wheel to millstones, that ground the grain into flour. Grinding ceased in 1947 and by the 1960s the mill had fallen into serious decay.

Over grown and lost to the world the derelict mill lay hidden in the trees on a small island in the River Derwent, in North Yorkshire until one day in 2003 it was discovered by Mo McLeod and Dave Mann who fell in love with the ruin and bought it in 2004. They had plans to renovate it and turn it into their home but they soon discovered that sadly this was not to be as they were turned down no matter what road they took.

Howsham Mill in 2003

Howsham Mill in 2003 ~ Photo Credit – Renewable Heritage Trust

Undeterred by all the set backs they decided to change tactic and formed the Renewable Heritage Trust with the help of the local residents with the aim of restoring the mill as an environmental study centre promoting renewable energy and local history and wildlife. It will also be available for use as a community venue for local people.

Photo Credit - Renewable Heritage Trust

Photo Credit – Renewable Heritage Trust

The first phase of the restoration was completed in 2007 and involved installing the new waterwheel and  an Archimedean screw as well as rebuilding the walls and roof of the granary to the north of the main building, allowing the installation of a kitchen and toilets as well as housing the control equipment for the hydro generation. Fund raising and grant funding enabled the installation of a new waterwheel and  the Archimedean screw to generate electricity and help fund the project in the long term. Much of the hard work of restoring the mill was done by enthusiastic volunteers, with families joining in for work days, and regular groups of trainee soldiers and school parties  helping out at the mill.

Archimedean Screw hydropower at Howsham Mill

Archimedean Screw hydropower at Howsham Mill

Both the waterwheel and the Archimedean Screw generate electricity from the fall of water over the weir. The reinstatement of the waterwheel will again harness the power of the river, but rather than driving millstones, this time will generate electricity. Both the water wheel and the Archimedean Screw are grid connected and excess electricity generated is sold to the National grid.

A view of the water wheel taken from inside Howsham Mill

A view of the water wheel taken from inside Howsham Mill

In June 2012 work began on restoring the main part of the building. Today, a decade on, Howsham Mill has been returned to its former glory as it was when it was abandoned in 1947.

Howsham Mill restored to its former glory

Howsham Mill restored to its former glory

Howsham Mill

Howsham Mill

The magnificent restored ceiling in Howsham Mill

The magnificent restored ceiling in Howsham Mill

Howsham Mill - copyright Eco Evolution)

The magnificent Gothic windows and stone work at Howsham Mill

The aim of the Renewable Heritage Trust is to make the building totally self-sustaining for the 21st century using revenue from power sales to fund future restoration and conservation work at the site.

The mill has underfloor heating beneath the flag stones which is a wet system with a sealed network of pipes connecting to a coil in the hot water tank, which is heated partly by the solar thermal panel installed on the roof of the mill and topped up by an immersion heater run from their own electricity.  A wood-burning stove connected to a flue liner has been installed in the original fireplace and will burn logs from the island.

Solar Thermal panels supplement the underfloor heating in the mill

Solar Thermal panels supplement the underfloor heating in the mill

The final stage of the restoration was the placing of the statue of Diana the huntress created by wire-mesh sculptor Nikki Taylor which replaces the original lead sculpture of the Roman goddess, most of which was taken for scrap.

Sculpture of the goddess Diana - Photo Credit

Sculpture of the goddess Diana – Photo Credit

Howsham Mill is located in a Site of Special Scientific Interest (SSSI) and Special Area of Conservation (SAC). The small wooded island has a wealth of native trees including ash, sycamore, oak, wych elm and hawthorn trees.  Above and below the weir are beds of water crowfoot, teeming with invertebrates eaten by fish and birds. Otters were re-introduced to the river in the mid-1980s and can occasionally be spotted from the island.

The weir on the River Derwent

The weir on the River Derwent

A rich diversity of plant and animal life

A rich diversity of plant and animal life


Photographs unless otherwise credited are copyright of Eco Evolution