Hydropower: Royally screwed on the River Thames

The ancient Archimedes' screw is coming into its own as a hydroelectric technology. The Queen buys two to power Windsor Castle.

More and more homeowners these days consider installing solar, wind or geothermal gear to cut electricity bills. But if your house is Windsor Castle, you can draw hydropower from the nearby River Thames.

The Queen of England this week accepted delivery of two turbines that she’ll plop down in the Thames in order to generate electricity for her royal residence at Windsor, west of London.

What is notable is her choice of hydro technology. The Queen has turned to a piece of antiquity, the Archimedes’ screw.

As it says on the label, the device is shaped like a screw – a big screw. Each weighs 40 tons and measures 12 meters (39 feet) long and 4 meters (13 feet) in diameter, according to the Daily Mail.

The Greek philosopher and engineer Archimedes invented the contraption (pictured, right) as a way to haul water up slopes into irrigation ditches. The water would travel up in the spinning threads as someone turned the device by a handle.

The Windsor project turns the idea upside down. A giant screw slopes downward in a weir. It spins as water plunges along its threads, turning gears that drive a turbine. Archimedes turbines have caught on in other installations in the UK, Holland and elsewhere (that’s a Dutch example pictured below).

Proponents say they are simpler and cheaper than other forms of hydropower, and less prone to breaking down. They also claim that they are more environmentally friendly because they are less likely to mangle fish.

Friends of the Earth approved of the Windsor project, which is a partnership between Southeast Power Engineering Ltd. and the UK’s Environment Agency.

"We urgently need to develop clean and safe energy to tackle climate change and build a greener economy and it's great that the Royal family is showing leadership in doing so,” FOE director of policy and campaigns Craig Bennett said in a press release. "Obviously schemes should be carefully located to avoid any negative environmental impacts - and in this case the Environment Agency says there'll be no adverse effects on wildlife, navigation or flood control.”

If all goes as planned, the two screws will start providing a dose of electricity to Windsor in November, and could supply all of the castle’s power by next year. The Royals could also sell excess electricity to the grid.

The turbines are expected to produce 1.7 million kilowatt hours per year, and cut CO2 emissions by 790,000 kilograms annually.

Keeping up international relations, the screws come from Holland, at a cost of £700,000, according to the Mail. Installation adds another £1 million to the bill, the paper says.

It’s been an eco friendly week for the Royals as Prince Charles became president of the World Wildlife Fund’s UK branch a few days ago.

Maybe the reigning monarch deserves the new title that the Mail bestowed her: The Green Queen.

Images: Top, David Iliff/Wikimedia Commons; Middle, Wikimedia Commons; Bottom, M.A. Wijngaarden/Wikimedia Commons

This post was originally published on Smartplanet.com

Show Comments