Tag → wind turbines

Vertical Axis Wind Turbine

12 July, 17:19, by homemadejoe Tags: , ,

Vertical Axis Wind Turbine Usage:

Because of the environmental concerns and energy issues facing by the world today, many countries have been trying to utilize renewable sources of energy. Wind, being a clean and plentiful source of energy is now setting a new trend in renewable energy sources.

Wind turbines systems are the most efficient way to generate electricity from wind energy. They vary greatly in size from homemade wind turbines to commercial scale wind farms.

Wind had already been used by people even in early times. Sail of ships utilizes wind to travel in high seas. Early American dwellers used wind mills for grinding corn, cutting woods and pumping water. Originally, mills were invented to grind corn. As men tried to find more efficient way to operate them, they led to an earlier version of today’s wind turbines. It featured large blades set in vertical wheel shape.

Several gears were connecting the wheel’s axle and the mill stone. As the wind turns the blades, it causes the mill inside to move and grinding the corn or wheat into flour. The present version replaces the mill with a generator that in turn produces the electricity. From these concepts, modern homemade wind turbines had been developed and are now being widely used to reduce households’ electric bills.

Wind turbines are generally classified into two types. These are horizontal axis wind turbine and the vertical axis wind turbine or the HAWT and the VAWT respectively. Both designs can be adapted for homemade wind turbines but HAWTs are more common. This is because horizontal axis wind turbines are found to be more efficient in generating electricity than vertical axis turbines.

The design of the horizontal axis turbines features three blades moving in horizontal circle similar to a clock’s hand. Besides the increased efficiency, HAWTs can also transfer the power generated from rotor to gearbox in much smoother way than VAWTs. Most of these turbines are mounted on top of towers being exposed to higher wind velocities. Unlike VAWTs that are designed to operate near the ground where there could be too many wind interferences.

However this set up offers the VAWTs an advantage over HAWTs. With HAWTs setting up HAWT system would require tall cranes and a yaw system. The periodic necessary maintenance has also to be done on top of those towers.
At the present, there are also two different designs of a vertical axis wind turbine – Savonius rotor and Darrieus model. The first type is similar to anemometer. But these are very inefficient offering an efficiency of about 5 to 10 percent. The Darrieus model on the other hand looks like an egg beater. This design makes use of an airfoil that operates as the airplane wing.

Though vertical axis turbines are about less than 40 percent efficient than HAWTs, they offer benefits in low wind situations. Also, because they are mounted close to the ground, they are safer and easier to build. They can also handle wind turbulence much better than HAWTs. Another important feature of vertical axis turbines is that they can operate using winds from any direction.

How to Increase the Maximum Capacity of Homemade Wind Turbines

28 June, 17:04, by homemadejoe Tags: , ,

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.