Based on the laws of aerodynamics, large wind turbines convert the kinetic energy of wind into electrical power. Large numbers of individual turbines are combined electrically so that the power outputs are in phase, and the result can be hundreds of megawatts of wind power. There are two distinct versions of wind turbines in use.
✓ A horizontal axis design is the most common and features an axis of rotation parallel to the ground. Figure 11-1 shows an upwind and a downwind embodiment of a horizontal axis turbine.
✓ Vertical axis turbines consist of a vertical shaft with blades (usually three) attached at the bottom and top of the shaft, as shown in Figure 11-2).
In the same way that an airplane works to provide lift for an aircraft, turbine blades provide torque to the mounting shaft. Different airfoil designs provide varying degrees of performance, and modern blades are far more efficient than those built decades ago. Constant improvements in the technology are providing better and better blade performances.
Of all the alternative energy technologies that are emerging, wind turbines demand some of the trickiest engineering designs. Small changes in nearly any aspect of a turbine design can result in major changes in performance. This is why there is so much ongoing design and experimentation. At some point, there will be enough data available to deterministically lock down the most optimal designs. In the meantime, expect to see a lot of different looking wind turbines. Following are some of the things engineers have to consider.
Was this article helpful?
Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable. The usage of renewable energy sources is very important when considering the sustainability of the existing energy usage of the world. While there is currently an abundance of non-renewable energy sources, such as nuclear fuels, these energy sources are depleting. In addition to being a non-renewable supply, the non-renewable energy sources release emissions into the air, which has an adverse effect on the environment.