The first hydroelectric turbine in London has been installed at Morden Hall Park on Wednesday.
Morden Hall Park is a National Trust park located on the banks of the River Wandle in Morden, south London. It covers over 125 acres of parkland with the River Wandle meandering through it. The estate contains Morden Hall itself, Morden Cottage, an old Snuff Mill, and many old farm buildings, some of which are now a garden centre and a city farm. The turbine mentioned will be installed in the river, behind the Grade II listed Snuff Mill and the 18th-century east mill waterwheel, which was renovated last year.
The 8.5 kW turbine, manufactured in the Netherlands, acts as a modern waterwheel, harnessing the power of the river to generate electricity. The turbine has an Archimedes screw design which is a machine that has been used since ancient times to lift water to higher levels, for instance for draining water out of mines. In the Netherlands, Archimedean screws are used to remove water from polders to create dry land areas below sea level. The screw is turned usually by a windmill or by manual labour. As the shaft turns, the bottom end scoops up a volume of water. This water will slide up in the spiral tube, until it finally pours out from the top of the tube.
The visitors centre, a former stableyard, is made into a green technology centre that has been appointed the country’s most energyefficient historic building. It has won both the design and innovation category in this year’s Royal Institute of Chartered Surveyors awards and a Green Apple Award. The building hosts a range of green technology, including three different types of solar panels – PV, PV-thermal and solar slates – six types of insulation, an air source heat pump and heritage-sensitive double glazing, plus a wash basin in the cistern of a toilet, allowing water used to wash hands to then flush the toilet.
It’s estimated that the Archimedes screw, costing £350,000, will generate 59,000 kWh a year. Enough electricity to power 18 average-sized houses, the visitor centre and the Snuff Mill in the park. The estate expects to sell the surplus (about 20% of the generation) back to National Grid. The hydroelectric turbine is expected to start generating energy in September 2012.