Developer Renewable Energy Systems (RES) is to erect a wind turbine on the site of its new offices at Kings Langley in Hertfordshire -- just 200 metres from the major motorway that encircles London, one of the busiest highways in the world. Despite its green-belt location, the local authority granted consent for the single 225 kW Vestas turbine. RES, which is yet to move to its new home, admits the site has a low wind speed. But its location means it will be seen by vast numbers of motorists. "It is the best advert you can get," comments the company's Chris Shears.