Archive June, 2011

How to Increase the Maximum Capacity of Homemade Wind Turbines

Maximum Capacity of Homemade Wind Turbines:

Wind turbines have been marketed as a viable solution for alternative energy. However, not all turbines are created equal. Some for those who are seriously considering making homemade wind turbines, here are some things that one could do to increase maximum capacity.

Increase Rotor Diameter

One of the best things to do to increase wind power capacity is to increase the rotor diameter. In other words, install bigger rotors. A bigger rotor will mean having a bigger sweep area, or the total area encompassed by the rotor as it turns. And as a rule of thumb when considering what rotor to install: the sweep area is directly proportional to the power output. A bigger rotor = more power. One important thing to consider though when planning on getting really big rotors, it is best making sure that all legal permits are met before installing the rotors. The reason for this is that big rotors in a wind turbine can be a potential safety hazard especially if things go wrong.

Setup the Wind Turbine in an Area of Strong Winds

Another factor determining overall turbine power is the wind velocity. A basic formula state that the overall power capacity of the turbine is proportional to the cube of the wind speed. So if the wind speed doubles, the power output is multiplied by two to the third power! It is therefore most recommended to setup wind turbines in areas where gusts are relatively strong and a common thing. Now, this may sound really exciting and all, but it could be a bit challenging to say the least. Not everyone has the luxury of living in a windy place. Those living in windy areas are definitely in luck, but for those who live elsewhere, it is high time to look for another good alternative energy source because wind power may not be the best available option.

Consider the Sea Level

Something that also has to be factored in when trying to maximize power outputs in homemade wind turbines in the sea level where the turbine is located. The closer one gets to sea level, the denser the air becomes. This is called air density and it plays a part in the overall output of the wind turbine. When setting up a turbine, it is best to place it just a few meters above sea level. Positioning a wind turbine in higher areas is still possible however, and a lot of people do it but setting up the turbine within sea level range is by far the most ideal.

Make sure to use high quality materials

Aside from all the factors listed above, maximizing power output from homemade wind turbines will also mean getting the top of the line materials for the job. There is a theory that the maximum possible energy to be extracted from any wind turbine is only 59.3 percent. That means even with a full gust, only 59.3% of that gust can be converted to useful energy! It is therefore important to make sure that all materials are high quality to maximize that 59.3% useable energy.

Computing for the Power Output of Homemade Wind Turbines

Power Output of Homemade Wind Turbines:

Just as it is with other homemade or do it yourself turbine projects, one of the most crucial things to consider, if not the most crucial thing is the power output. And the same goes with homemade wind turbines. Many beginner DIY enthusiasts usually fail to consider the power output factor when building their own projects. Initially they start out with all the excitement in the world, putting all the niceties and bells and whistles in their project, only to find out later on that their turbine’s power output just does not meet their standards. And most often than not, the project has to be redone from scratch.

Determining the power output of the wind turbine is not as insanely difficult as one might initially think. However, it does require a bit of patience and a bit of calculation. However, to keep things simple, there are just some basic guidelines to follow when computing for the power output of homemade wind turbines:

1.)    The power output of the wind turbine is directly proportional to the area swept by the rotor. This means that if the wind turbines swept area is doubled – due to perhaps a much larger rotor blade, the power output will also effectively double. 2X Rotor = 2X Power.

2.)    The power output of the wind turbine is proportional to the cube of the wind velocity. Essentially, when the wind doubles in strength, the power output of the turbine will also increase by a factor of eight! 2X Velocity = 2x2x2 Power.

3.)    Another factor of computing for wind power is air density. Air has a density of around 1.23 kilograms/m3 at sea level – and the air density varies depending on how high or low the area is when compared to the sea level. But to keep things simple, we will be using the sea level data as a reference point.  (1.23 kg/m3)

Now for the formula: To sum it all up, the theoretical power that a wind turbine can generate is equivalent to velocity multiplied by swept area and then multiplied by air density.  (Power = Velocity x Area x Density). This is supposedly the maximum power the turbine can generate.

Getting the theoretical maximum power for homemade wind turbines however, will not be applicable in real world application. This is one of things that get a lot of DIY enthusiasts off track. This is because the computation in theory does not consider limitations of wind energy and also the equipment used. A good example for this is the computation for the world’s largest wind turbine. The turbine, when computing for its maximum power, should have a power of 21 Megawatts. However, the actual power rate is only at 5 Megawatts. The reason for this is that there are other factors to be considered like turbine efficiency, drag, and heat transfer. There is also such a thing as the Betz limit (or the Betz law). This law is a theory about the maximum possible energy to be derived from a “hydraulic wind engine”, or a wind turbine. It states that no turbine can extract more than 59.3 percent of the kinetic energy in wind.