German power group RWE Innogy is investing £6 million (EUR 9.5 million) for a minority shareholding in Quiet Revolution Ltd, a small wind turbine company in the UK. A further £1 million has come from private investors. Quiet Revolution is manufacturing and developing small-scale vertical axis units particularly suited, claims the company, to generating power in urban areas. The lower tip speed of small vertical axis generators means they are quieter than conventional horizontal axis machines and more able to cope with gusty winds around buildings that are constantly changing direction, claims the company. Quiet Revolution's first commercial turbine is the 6 kW triple helix shaped QR5, at five metres tall and three metres wide. It can be mounted on buildings or stand alone. The first commercial machine was installed at Dagenham in April 2007 and so far around 30 have been built around the UK with a further 45 at the manufacturing and installation stage. Also under development are the 50 kW QR12 and the 2.5 kW QR2.5 turbines, which are expected to be in regular production from 2010. The company is based in London but manufactures its machines at Pembroke Dock in Wales. RWE Innogy's investment comes out of its EUR 50 million a year venture fund which aims to provide equity capital or similar funds to young companies during their start-up or growth stages. "The purpose of our involvement," says Crispin Leick of RWE Innogy, "is to take this promising technology towards mass production, so that it will become commercially usable."