Posts Tagged ‘Wind Energy’

Windmill Blades

April 2nd, 2010 | admin

The energy crisis caused a considerable growth of interest in alternative sources of energy in the past few years. Among the several energy sources being explored, wind energy which is a form of solar energy, become a significant energy source. If the efficiency of a windmill can be increased, then the dependency on expensive, polluting power generators will be reduced. By doing this, we would be helping the environment and economy at the same time. In order to increase the efficiency, we must analyze the components. The most important components of a windmill are windmill blades.windmill blades before instalation

Factors affecting the performance of windmill blades:

Shape of Blade

This is important because if an optimum blade shape is discovered, then the overall productivity of a windmill can be increased. The shape of windmill blades highly influences their rotation. Few different shapes of windmill blades available are: the flat, rectangular ones, the wing shaped ones and the ones with edges tapered to a thin line or edges rounded similar to the ones of an airplane wing. In the case of the horizontal axis windmills, the wing shape has proved to be the most efficient one. The vertical axis windmills works very well with all the shapes of the windmill’s blades, however the best performance is given by the flat ones as well as the ones with both edges rounded.

Material for Windmill Blades:

Decades ago wood was used to make the windmill blades. Nowadays wood is still used but the design is however different and a lighter wood material is used, to carve the blade and faster speed rotation.
The latest blade design is made of fiber-glass and epoxy resin. Although this blade is in its first stages and not yet marketed, what makes it unique is its curvature like tip which allows it to catch low wind speeds.

However some turbine blades have even been made with the raw material made for PVC piping which have been found to break in strong lengthy winds, but are inexpensive to replace.

The turbine blades made of carbon fiber are light weight, and has a razor sharp edge which allows it to literally cut through the wind and makes it almost silent. This material is preferred and is used in most wind turbine machines sold today.

Length of windmill blades

The length is also an important factor. If a blade is longer, it covers a larger surface while it rotates, hence they can catch more wind with every rotation. This may show the way to more torque. These blades are growing longer from the 30 to 40 meters up to 60 meters.

Number of Blades:

The most important thing to take into consideration when talking about windmill blades is their number. The old ones normally had 4 very heavy blades. Majority of them were use in grain grinding. After that three blades became the most popular. More blades seemed to raise noise and slow down the rotation of the turbine’s propeller formation. After more research was done the perception of using more than three blades was no longer a factor. Currently, the most recent windmills are equipped with two or three blades.

Surface Treatment

This is important since if an optimum surface treatment can be determined, the blades would not only be protected from the elements but also be more productive.

Tip Speed Ratio

The tip speed ratio is very important. The ratio of the speed of the wind and the speed of the blade tips is called Tip Speed Ratio. High efficiency 3-blade-turbines have tip speed of 6 to 7. The tip speed ratio is directly proportional to the windmill’s productivity.

If the efficiency of a wind turbine is improved, then more power can be generated thus decreasing the need for costly power generators that cause pollution. This would also lessen the cost of power for the common people. The wind is factually there for the taking and doesn’t cost any money. Power can be produced and stored by a wind turbine with little or no pollution. If the efficiency of the common wind turbine is enhanced, the common people can cut back on their power costs enormously. Wind energy contributes very little pollution, toxic by-products or greenhouse gasses; it is still a sufficient supplement for non-renewable fuels


  1. Wind energy is one of the lowest-priced renewable sources of energy.
  2. Wind energy is the fastest growing section of all renewable energy sources.
  3. Wind energy is incredibly exploited in Germany where Germany leads the way with 8750 MW of electrical energy produced from wind energy.[#1]
  4. Wind energy is more used in Europe than in America, because of favorable climate conditions and because of USA traditional relying on fossil fuels.[#1]
  5. Wind energy is mainly transformed form of the Sun’s energy. Wind energy is airflows created by different air temperatures in different locations. The sun does all these Earthly dynamics. That’s why wind energy is solar energy.
  6. If properly developed, wind power could successfully reduce carbon emissions in the US by at least one third every year and help realize a global carbon dioxide reduction of 4% yearly.
  7. In 2006, seven wind turbines off the coast of Dublin, Ireland, represent the largest wind turbines in the world with a capacity of 3.6 MW each. By 2009, the largest wind farm is positioned in the US. It is the Florida Power and Light’s Horse Hollow Wind Energy Center, in Taylor County, Texas. It has 421 wind turbines having a capacity of 735 megawatts.
  8. In 2005 wind energy generated less than 1% of global energy and generated 58,982 MW worldwide. By end 2008 it measured 27,051 MW. 8% of Europe electricity is derived from wind, well ahead of coal and natural gas. The US is the country with the largest wind energy capacity and China exceeded its 2010 target of 10,000 to reach 12,200 MW.[#3]
  9. At the 2004 Wind Energy expo in Hamburg, Germany Danish company LM Glasfiber aired out the world’s longest windmill blade. The blade was 61.5 meters long and weighed in at just less than 18 tons, which as far as 61.5 meter windmill blades go, is extremely light. When three blades are positioned on a windmill they have a rotary diameter of 126 meters. [#4]
  10. Wind energy theory was discovered in 1919 by the German physicist Albert Betz and published in his book “Wind-Energie”.[#1]
  11. In 1995, the cost of electricity generated from gas and coal was between 3 and 4 US cents per kilowatt-hour, nuclear power cost 10 to 14 cents, wind power was 5 to 7 cents and solar photovoltaic power was 25 to 40 cents. But the price gap between non-renewable and renewable energy is closing. By 2030, wind, solar and biomass power may cost less than fossil or nuclear fuels.[#2]