24 August 2011 Last updated at 17:41 ET

Windsor Castle will be powered by hydro-electricity

The castle's electricity will be supplied by renewable energy sources

Windsor Castle will be powered by hydro-electricity, the royal household has said.

The castle will be supplied by Southeast Power Engineering Ltd (SEPEL), after former renewable energy plans were halted in 2009.

Two hydro-electric turbines at Romney Weir on the River Thames will be lifted into position by a crane in late September, the firm said.

The 40-tonne Archimedes Screw turbines will be ready to operate from November.

SEPEL director David Dechambeau said he was "over-the-moon" to have the Queen as a customer.

SEPEL is working in partnership with the Environment Agency, which is leasing the weir.

A Buckingham Palace spokeswoman said: "I can confirm that the royal household now has an agreement in place to purchase the energy generated by the hydro scheme, implemented by SEPEL."