Wind Power:
A Growing Renewable Energy Resource

The purpose of this web site is to provide a simple tutorial about using wind power to generate electricity. It includes an information about the resource base, technology, current use and future potential of wind generated electricity. This web site also includes links to other web sites offering more in depth information on wind power and renewable energy technologies. Hopefully you can find a link to answer your questions.

History:

Wind power has been harnessed by mankind for thousands of years. Wind filled the sails of explorers and fueled trade throughout the world. The Dutch used wind to claim land from the ocean, and early European settlers in the American West used wind to pump water for farms. During the first half of the 20th century wind was used to provide electricity for many rural areas before the expansion of the electrical grid offered a cheaper and more reliable form of power.

Today:

Following the energy crunches of the ‘70s, a renewed interest in wind began to develop. Spurred on by government incentives (now largely extinct), wind farms began to sprout. California leads the world for installed capacity - 44%. During 1994 California produced 3.2 billion kWh from wind power.

In the Altamont Pass, near San Francisco, the use of wind power on farmland increased the value of that land from $400 per acre to $2000 per acre, while only reducing the available grazing land by 5% (Scientific American, Sept. 1990). This energy costs $0.075/kWh, though in some areas, due to greater wind power, the price is $0.05/kWh.

By rejecting nuclear power, Denmark has made the greatest commitment to wind power of any nation. Second only to California, Denmark has 540 MW of installed capacity and produced 1.1 billion kWh during 1994. Six of the top ten wind turbine manufactureres (including #1) are Danish companies.

A wide range of generating capacities allow wind turbines to fill a wide range of applications and sites. Individual producers, generating electricity for their own home needs may use a turbine as small as 10kW (this would power one hundred 100 Watt light bulbs at peak power). Larger utility based wind farms may use turbines from 50kW all the way up to 2 MW (1 MW = 1000 kW). The typical sizes for modern utility applications are between 200 and 300 kW.

Wind power can be tapped in a variety of places. To see some pictures of actual wind turbines in action click to see a typical “row farm”. Wind can also be tapped on water, or as mentioned above, on farms.

Are you interested in finding out how to plan for your own electricity generation from wind power?

Click here for part 1.Click here for part 2. This information is brought to you courtesy of Mick Sagrillo. You’ll find all kinds of good information that may not be directly obvious, but makes common sense.

Intermittency:

One particular problem with wind energy is the intermittent nature of the resource. The wind does not always blow. This is perhaps the leading criticism of wind power today. For the home generator, batteries can be used to store the power, however this increases costs and reduces the environmental benefits. A solution is to use the electric grid as a “storage” mechanism. During times when the turbine is producing excess capacity, the electric company purchases your power. During times when you need more power than you can produce, you can “buy back” the power you sold.

As for the large utilities, wind power is not a large enough energy source at the current time for intermittency to be a problem. Given that the electric grid connects large areas of land together (1/2 a continent), it may be found that the lack of wind in one area at a particular time may be made up by wind from another area and vice versa. In other words, an overall balance in the system may be maintained.

Another way of dealing with the intermittent nature of wind power (and other renewable technologies) is to use the exectricity for electrolysis. Running a current through water results in the seperation of the hydrogen and oxygen. Using the hydrogen for fuel recombines the hydrogen and oxygen, forming water.

Resource Base:

To see a map of the wind power resource in the U.S., click here. This image comes to you courtesy of the U.S. Dept. of Energy. Most wind turbines operate at 30% efficiency. To estimate the turbine potential for electricity generation in a particular area, multiply the wind’s power by 0.30. It is important to note that the wind estimates are based on average wind speeds. Why does this matter?

The wind’s power is determined by multiplying (density of air)(area measured)(wind speed cubed). The area measured is the area swept out by the rotating blades. Because of the cubed factor governing the velocity, a small increase in wind speed leads to a much greater increase in power. Thus using the average wind speed does not reflect the actual power over time - it does reflect the dependable power over time. A general rule of thumb is to double the power found using average wind speeds.

The technology used to convert wind power to electricity is fairly simple. The blades of the turbine are similar to airplane blades. There are some other designs, but the basic two or three bladed turbine is the most widely used. The rotation of the blades spins a turbine. Turbines are used in almost all electrical generating technologies. Within the turbine are magnets whose rotating motion causes an electrical field, and we get a current flow.

It would appear that wind power has a definite future for generating electricity. Competition within the growing industry of wind turbine manufacturers and the continued addition of turbines in the energy mix should help bring down the price of electricity generated from wind. If you want to find more information about wind, or other energy sources and ideas, the following list should get you started (these are in addition to the links found above).

Solar energy and renewable energy related servers.

Frisse Wind, a successful Dutch wind cooperative.

World Power Technologies, Inc., a wind turbine manufacturer. No, they didn’t pay me. There’s lots of good information here.

U.S. Dept. of Energy Energy Efficiency and Renewable Energy Network. Exercise those tax dollars!

Thanks for reading! Y’all come back now, y’hear!