How hydro power works: The Archimedean Screw

Cast your mind back to history lessons and the Greek scientist Archimedes. He invented the Archimedean screw for pushing water uphill. It's been used for thousands of years to help irrigate crops.

Several years ago manufacturer Ritz Atro discovered another use for the screw. By reversing the process so that the weight of the water turns the screw electricity can be generated.

An Archimedean
screw being used to
generate electricty.

It works in exactly the same way as a dynamo on a bicycle wheel.

Instead of the wheel being turned by the cyclist, it's the screw being turned by the water.

The screw is installed alongside a dam or river weir. Water is diverted from above the weir, flows down the screw and back into the river.

Archimedean screws have a long life span of around 40 years and are ideal for sites with a low head of water.

Small scale community schemes

Water Power Enterprises link local action on climate change with the regeneration of communities. They find river weirs that are suitable for long-term projects.

We're using a 4,000 year old technology on 200 year old river weirs at no cost to the planet.

Steve Welsh, Water Power Enterprises

The local community is encouraged to co-own the scheme. As such they benefit from the sale of the hydroelectricity. Profits are re-invested back into the community through local initiatives.

Did you know?

Less than one third of the world's practical hydro capacity has been developed.

British Hydro Association

Around the UK

Hydro power is an underated source of renewable energy. During the Industrial Revolution, thousands of river weirs were built to power water wheels.

Map of potential hydro
power sites in the UK

These weirs can be given a new lease of life, only this time to produce electricity.

Water Power Enterprises are developing the UK's first community owned scheme in New Mills, Derbyshire.

It is hoped that this pilot scheme, which opens in July 2008, will help raise the profile of small scale hydro power within the UK.

Resources

The New Mills project

Torrs Hydro New Mills scheme
The UK's first community-owned hydro power scheme in New Mills, Derbyshire.

Water Power Enterprises
Social enterprise that works with local communities to promote hydroelectricity schemes around the UK.

Archimedean screw - the technology
(PDF†) format - 1.4 mB) Mar 2005
Brochure of German manufacturer Ritz Atro which has been making Archimedean screws since 1969.

The potential for hydro power

Small scale hydro power atlas
Interactive map showing potential for small scale hydro power in the UK.

Lancashire and Yorkshire Renewable Energy Planning Study
(PDF†) format - 1.6 MB) 1998
Report naming 68 potential small scale hydro sites in Lancashire and Yorkshire - see page 84. Contact your regional renewable agency for more information on potential sites where you live.

Restats renewable energy map
Interactive map which monitors and reviews renewable energy projects in the UK. Covers both planned and approved sites.

Useful contacts

British Hydro Power Association
Members range from hydro developers and generators, investors, consulting engineers to
manufacturers and suppliers of equipment.

European Small Hydro Power Association
Features articles covering the development and potential of small scale hydro power.

Renewable energy

A Bright Future
(PDF†) format - 166k ) Mar 2006
Friends of the Earth's technical report which demonstrates how renewables and CHP could meet up to 65% of UK electricity demand by 2020.

How to support local renewable projects in your area
A guide to how Friends of the Earth can help you support a project in your area.

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