Vertical Wind Turbines suitable for home owners are usually rated by the manufacturers at around 2 KW, but they can go up to 5 KW.
Their defining characteristic is that the blades rotate around a vertical axis, this is in contrast to the commonly seen horizontal turbine with the propeller type of blades..
One of the main differences between vertical axis and horizontal axis turbines is that a vertical turbine does not need to swing into the wind as it shifts direction. The technical term for this is yaw. In order to capture the power of the wind all horizontal turbines need to do it. A vertical turbine can harness the wind?s power from any direction and so is simpler in design with fewer moving parts and less maintenance.
There are two types of blades found on vertical axis turbines. These are lift or drag devices.
The lift turbines are sometimes known as Darrius Turbines after their inventor George Darrius. The rotating blades are aerofoil in design much like an airplane wing. The leads to more efficient operation, so that for a given power output the span of the blades can be smaller. While this might seem an attractive property for the urban environment, greater blade speed leads to greater noise.
A lift type of design is not inherently self starting. Manufacturers have overcome this issue by incorporating a small drag rotor to get the turbine moving or alternatively feed power into the turbine to start it up.
The drag turbine as we have discussed is not as efficient as the lift turbine, but it does have a number of advantages. It is self starting. This means that the design can be simpler. It also runs more slowly. This means it is less noisy. Overall drag turbines have been available for longer than the lift turbine and have a good track record of operation in the real world.
Compared to the solar industry, the wind power is still very new in the urban environment. They key thing with wind is to have enough of it, an average of at least 5 m/s is needed. If there is good wind at the site then it can be much more cost effective than solar.
Before you go to the expense of buying a wind turbine, which can cost around $10,000 to $15,000 for a 1 KW unit, it is essential that you test out the micro environment around the proposed site of installation this can be done with a measuring device called an anemometer
Author: Gavin RyderThis author has published 2 articles so far.