Eco Evolution featured in The Farmers Journal (14 Nov ’09)

Turning the screw on power

Turning age old technology on its head has started to allow one Irish company to produce electricity from flowing water.

Ferns based company Eco Evolution (www.EcoEvolution.ie) has become the first in the country to commercialise the Rehart range of Archimedean screw hydro turbines.

Frank Gethings, managing director of Eco Evolution, said “Archimedean screws were traditionally used as water pumps to lift water from one level to another. Archimedean screw hydro turbines work in reverse. Water from a river or stream flows down the screw causing it to rotate. The screw is coupled to a generator via a gearbox and hence power is generated.”

Like many green energy companies they supply wind turbines and solar panels but are finding huge interest in hydropower.

The system can range from 1kW up to 130kW on a single screw system. The first large system of 120kW is to be installed in Omagh, Co. Tyrone, to provide electricity for a leisure centre.

The Archimedean screw is suited to low head sites and can cater for heads of between one and 10 metres height and can take flow rates ranging from 100 to 10,000 litres per second.

For larger flows, two or more screws can be used.

Frank said there is scope for installing it on farms but having an existing mill or works will greatly reduce the cost. It costs €20,000 for the equipment for the 1kW system, but additional site works have to be carried out. Cost efficiency is an issue of scale. A 300kW system might cost €1,000 per kWh to install but a 1kW system might be €20,000.

The system allows debris to flow through and has also been proven to be fish friendly.