Vertical-axis wind turbines, (VAWT's) are less common than the horizontal versions and are generally relegated to the small domestic end of the market place at predominantly less than 4kwp outputs. However, they are efficient and relativity quiet in operation and arguably  visually more attractive.

The VAWT as its name implies has its main rotor shaft running vertically, rather like a spinning corkscrew in appearance. Vertical-axis wind turbines have blades that go from the top to the bottom and are usually wrapped around the central mast. The Turby VAWT from Holland has a distinctive design and has gained favour with many commercial institutions and local governments commissioning installations of units on top of office buildings and factories.

To attain maximum performance from the VAWT it must be mounted as high as possible, low level installations below 20 metres do-not perform efficiently due to the lower wind speeds nearer the ground and turbulence that often occurs from surrounding trees, buildings and other geographical elements.

The advantage of a VAWT is that the generator and its gearbox are located at ground level which make the structure much lighter and less costly as the pole does not have to support this additional weight or stress factors in stormy high wind conditions. The VAWT being multi bladed can catch wind from any direction which is of great advantage when there is no predominant or predictable wind direction. Also the huge energy losses often attributed to horizontal turbines "hunting" for the wind are removed.

At the the top end of the market for vertical axis wind turbines, the British manufacturer "Quiet Revolution" produce a very highly engineered unit which is almost "art", unfortunately, its high capital cost and lower output, are set against the true beauty of the engineering.

If you would like more information or a site survey to assess the possibilities of installing a wind turbine at your site please contact us.