It was interesting to read the letter extolling the virtues of the vertical axis wind turbine (VAWT) as opposed to the HAWT (horizontal axis wind turbine) (Letters last week).
This debate has been a recurring theme ever since their reappearance in the 1970s/80s as a greener alternative means of energy generation compared to coal fired power stations.
I recently visited Melton Mowbray and was surprised to see a VAWT installed on the roof of The Kettleby Cross.
The VAWT has its origins in China and Persia as early as 700BC so its technology is well established. The HAWT appeared in Occidental Europe circa 1300AD though it does not seem to be known why the axis was rotated through 90˚, however, it set the trend for future designs.
Both types of wind turbine have their adherents though both have a niche in the arena of electrical energy generation. The VAWT is excellent for taking advantage of prevailing winds at low level whereas the HAWT construction is better suited for higher level prevailing winds.
Dan Little, email@example.com