Recently, we’ve been approached by potential customers inquiring about small wind turbines and how they might help their community generate energy. We get a lot of questions about the type of turbines we provide, and how they compare to other turbines on the market. To explain things further let’s start with the basics of wind power and look at one of the fundamental key differentiators of Turbines; swept area.
Although there are some exceptions in the educational field, most consumers install wind turbines to generate energy. Wind turbines require wind to generate this energy. Small wind turbines, like the ones TWN Wind Power installs, generally operate well in wind speeds of 5 m/s – 8 m/s. It’s rare that you would see average annual wind speeds at the higher end because most small wind turbines are located in populated areas (not on a mountain ridge) that center around community buildings, homes and businesses.
Below are a few things to keep in mind when you’re considering investing in small wind:
Bigger Is Better
Why do big wind turbines at wind farms have such long (120 feet or longer) blades? To catch more wind! This is referred to as the rotor diameter or ‘swept area’. The bigger the area to capture the wind, the more energy you will generate. The same concept applies to small wind turbines; the larger swept area allows the generation of more energy.
Aim For Quality Wind
When water flows down a stream, the more rocks in the stream, the more the water has to move around the rocks. The same goes for wind – they both follow “fluid dynamics” (don’t worry, were not going to get too technical here).
It’s important to remember that the better the quality of wind is, the less wear and tear you will see on the turbine and the more energy you will generate. Keep in mind that when you’re choosing a space for your turbine(s), you want to avoid obstructions and/or turbulence that can be caused from trees or buildings their area.
The three most common mistakes that people make with small wind installations, according to Mick Sagrillo, a 28-year small wind industry veteran, are: 1. Too short a tower; 2. Too short a tower; and 3. Too short a tower.
If you can afford it, go higher! The higher you go the better quality of wind you’ll see and the less you’ll have to worry about turbulence.
Ignore ‘Rated Power’
Is a 10kW turbine better than a 6kW turbine? Are two 50kW turbines from different manufacturer’s the same? Wrong! Rated power is one of the most misleading and least interesting parameters of any wind turbine. It doesn’t tell you anything about energy production and considering you should be interested in how much energy your turbine produces, that’s a problem.
Rated power of a wind turbine could be useful when you’re looking to quickly compare, or get a feel for, the size of the wind turbine, but only if those rated power numbers were taken at the same rated wind speed, and if the manufacturer is giving you a realistic number (many inflate rated power). A much better measure of turbine size is, simply, their rotor diameter. As outlined above, it’s by far the best predictor for power output.
In this blog post we’ve covered just a few important aspects of a successful distributed wind energy project. It’s important to remember that a wind specialist can further analyze your specific site requirements as each project is unique.