Wind Energy

Wind energy is the conversion of energy from the wind into a useful form for human use. Wind turbines convert this energy into electricity. Windmills harness wind for mechanical processes; windpumps pump and move water; sails "catch" the wind to move water craft. More specifically, small wind turbines can be used by the homeowner for personal, residential use (especially if wind energy is a good fit yet it isn't offered on a commercial level).

Some Background

The advantage of using the wind for energy is that there are no greenhouse gas emissions. It is one of the cleanest types of renewable energy. Some negatives are the aesthetic considerations when positioning windmills in the countryside. Another issue is the erratic nature of wind speed and sometimes large variations between locations.

There is a long history of wind power that stretches back over five thousand years. The technology today to harness the wind is putting a new spin on an old idea.

The wind results from the uneven heating of the earth by the sun - more intense and hotter at the equator and less energy and colder at the poles. There is differential heating at a given latitude due to the specific heat differences between land and water. Also different materials absorb different amounts of energy. Warm air rises, cold air sinks and as a result, air moves in the horizontal to attempt to reach an equilibrium. If this isn't enough, the earth also turns on its axis - one revolution per 24 hours. The resulting effect results in "wind". The wind is faster aloft (where there is less friction) and slower at the surface.

There is a distribution of wind speed across the U.S. that needs to be considered when planning to use wind energy. Locations along the coastline and mountain top locations tend to have stronger winds, on average. However the strongest continuous winds are located in the upper levels of the atmosphere in the jet stream. These ribbons of winds circle the globe around 4-8 miles up and can range from 100 miles per hour in the summer to as much as 200 miles per hour during the wintertime.

Main Points to Consider for Wind Energy

Wind farms - a group of wind turbines in a location for production of electric power - can consist of several hundred individual turbines and cover hundreds of square miles. The land between turbines can still be used for agricultural or other purposes. There are thousands of wind turbines around the world. The country with the highest windpower capacity is China, followed by the U.S., Germany, and Spain. However Europe accounted for 48% of the world's total wind power energy in 2009. (source Wikipedia for wind power) Some specifics to keep in mind:

• Once a plant is constructed the cost is typically around 1 cent per KWh

• There are subsidies and tax credits for wind energy

• Due to wind being intermittent, it makes for large challenges if this becomes a primary source of energy. Twenty percent or less of the total shouldn't be a large problem

• Wind power has negligible fuel costs, but high capital cost (i.e., construction of infrastructure)

• small scale wind generation systems can produce as much as 50 KW of electrical power for rural communities

• densely populated areas can have too much wind turbulence (around highrise buildings, for example) that can adversely affect how effective this technology is

Although wind power has some problems, it might be an important source of energy for some people to lesson their dependence on the traditional grid. If large-scale wind energy is offered, it is worth a look. If it isn't offered in your community, it might be worthwhile to consider a small wind turbine - especially if you live in a rural community. Wind energy should be seriously considered as a good way to reduce dependence on fossil fuels if offered in your area.