Waterwheels ~ Ancient Wheels of Power

Travelling throughout the country both here in Ireland and in the UK I see mills dotted around the countryside that are just derelict structures on a river bank and some that are working mills with water wheels generating 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.

Derelict Mill and Waterwheel

Derelict Mill and Waterwheel

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.

Bretts Sion Mills

Working 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.

Derelict Mill and Wa

Derelict Mill and Waterwheel

If a mill has a vacant wheel pit it is possible to construct a water wheel which is aesthetically pleasing and brings the character back to the old mill.

Waterwheel Components

Waterwheel Components

 

Completed laser cut waterwheel

Completed laser cut waterwheel

The installed laser cut waterwheel

The installed laser cut waterwheel

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.

If you are the owner of an old mill or indeed a mill site and would like to find out more please contact us here for further information and we will endeavour to point you in the right direction.

All photographs are copyright of Eco Evolution

Archimedean Screw Hydro Turbine – Old Technology New Application

The Archimedes Screw has been used for pumping water for over 2000 years. Applying the principle in reverse, the same equipment now offers a new method for generating power from water, providing a fish friendly and highly efficient alternative to a conventional turbine.

Each Archimedean Screw hydropower system is manufactured to be site-specific, with a choice of three designs – steel trough, closed compact and open compact – depending on which is the most appropriate and cost-effective for each individual site.

Closed Compact –  Key Benefits:

  •  Screw + trough + gearbox + generator are all assembled into a single unit at the factory.
  • Civil works on site reduced to a minimum.
  •  Installation time considerably reduced (approx 3-4 hours)

 Open Compact – Key Benefits:

  • Manufactured as a self-supporting U-shaped steel construction minimising necessary civils work on site.
  • Generator unit is an integral part of the construction, easily accessible via a weatherproof, hinged generator cover.

 Steel Trough – Key Benefits:

  •  Concrete foundation cast in situ.
  • Screw is supplied complete with its steel plate trough
  • Backed up with concrete after assembly and alignment.
  • Optimum clearance between trough and screw is guaranteed.
  • Civil works on site are reduced.

Closed Compact

Open Compact

Steel Trough

Eco Evolution are appointed agents in Ireland of Mann Power Consulting Ltd (UK) who specialise in the Archimedean Screw hydro turbine. The Archimedean screw hydro turbines are suited to low-head sites and are fish friendly.

As pioneers of Archimedean screw generating installations in the UK and Ireland, Mann Power believe that Rehart manufacture the best equipment on the market.

£1m hydro-electric project set to be biggest of its kind in Europe

Eco Evolution appointed agents in Ireland for Mann Power Consulting Ltd., the Archimedean Screw hydro turbine specialists in the UK.

A £1MILLION green scheme to turn Totnes Weir into a mini power station will be the biggest hydro-electric project of its kind in Europe.

The scheme — which could be in action powering up King Edward VI Community College by the beginning of 2012 — involves installing a four metre diameter Archimedean screw turbine to fill the 20-metre long sluice at one end of the centuries old town weir.

There are already 15 similar water-powered turbines operating in the UK and another 100 across Europe.

But the Totnes turbine’s size and its 200 kilowatt output would make it the biggest in Europe so far, revealed Dave Mann, the boss of Yorkshire company Mannpower.

It would harness the power of the 13 tonnes a second of water that pours over the weir which would then be used to provide electricity for the classrooms of more than 1,800 pupils at what is one of the largest schools in Devon.

“We have calculated that it will produce as much power as the school uses,” Mr Mann explained as he outlined the project at a public meeting at the college.

A similar, but slightly smaller screw, was installed at the River Dart Country Park by Mr Mann’s company and has been powering the park successfully for the past three years.

A consortium of local investors, called the Dart Renewable Partnership, has already bought the weir from one-time Autotrader boss Malcolm Barrett for £75,000.

The deal included land next to the weir where there are proposals to build a small classroom complex which would be used as part of a KEVICC educational project involving power generation and the river environment.

Mr Mann aims to submit a planning application for the project next month and begin construction in July next year and the turbine could be producing power for the school and the national grid by early 2012.

Mannpower has already held talks with fishing organisations, owners of waterside properties, the Environment Agency and KEVICC.

Around 20 members of the public, local councillors and representatives of interested group were at a public exhibition outlining the project at KEVICC’s Ariel Centre.

The scheme also involves building a fish ladder up the weir for salmon and trout which spawn in the upper reaches of the Dart — and installing underwater cameras and fish counters to monitor the fish population.

Fish expert Peter Kibel explained that the current fish ladder was too long and too difficult for smaller fish, leaving them easy prey for seals which swim up river to take advantage of salmon and trout trapped in the weir.

It is also planned to remove the diagonal concrete ledge across the weir built as another aid for fish.

That will stop the force of the water being directed to one side of the river which has eroded the bank by 20ft in the past two decades.

This will allow water to pour over the weir in a more direct route and eventually wash away the mud island downstream at low tide.

Source:  http://www.mannpower-hydro.co.uk/news.php