City Hall is one of number of projects to receive a grant

Since 2002, £20m has been distributed under the Solar Photovoltaics Major Demonstration Programme.

The grants were announced by energy minister Malcolm Wicks on Tuesday.

Solar projects given grants City Hall, South Bank - £270,757 Crown Estates, Regent Street - £57,948 Presentation Housing Association Ltd, Consort Road, Peckham - £23,615 Octavia Housing and Care, Kensal Road, Kensal Town - £122,744 Costain Engineering and Construction Ltd, Acton High School - £45, 702 Shoreditch Trust, Shoreditch Canalside Workspace - £33,658 Ashburton Learning Village, Croydon - £106,946 Hillview Ltd Commercial units, Croydon - £52,371

He said: "Solar is a clean, green energy source that the government is supporting through this funding programme and which we will continue to support in future with the Low Carbon Building strategy currently being developed."

The programme aims to help the Government reach its target of 10% renewable energy in the UK by 2010.

The grants are distributed by the Energy Saving Trust on behalf of the Department of Trade and Industry (DTI).

London's mayor Ken Livingstone said: "The decision of the Energy Saving Trust and the Department of Trade and Industry to back this project at City Hall with a grant is extremely welcome and sends a strong signal encouraging the use of renewable technologies.

"I want London to take the lead in applying renewable energy technologies and if we can install photovoltaic panels at the heart of London government, this will be a symbolic and important step forward."