Wind Powered Electricity

Wind farm in California Central Valley
Wind farm in California Central Valley

Parts/Contexts:

Any region with high average wind speeds.

Keywords:

wind power, wind farms, electricity

Predecessor Patterns

. . . It makes environmental and economic sense to use Local Energy Sources especially in lieu of depending on expensive foreign sources of energy. Wind power has tremendous potential as a local energy source in many parts of the world.

Problem Summary

Where the wind blows strong and often, it is wasteful to not harness it for generating electricity.

Analysis

Anyone familiar with the windmills in the Netherlands and on farms throughout the world knows that wind can be harnessed to grind grain, pump water from wells, and so forth. These can be valuable sources of energy even where the winds are not particularly strong or steady. However, the biggest potential for wind power is to use it to generate electricity in areas where the average annual wind speed is relatively high.

Using petroleum or natural gas to generate electricity when they are so critical for other uses, like powering vehicles, in regions that have lots of wind makes no environmental, economic or strategic sense. While this problem exists in every region and every country that has large "wind corridors", we focus here on an analysis of the problem in the USA.

Wind Power Sources

Map of available wind power over the United States.
US map of available wind power, indicating wind power density class.
Where average wind speeds are the highest use of wind power is the most economical. Globally these places include much of North America, the southern tip of South America (Tierra del Fuego), Greenland, most of Europe, Northern Africa, eastern Asia, most of Australia, and anywhere there are mountains. The top 5 countries producing electrical wind power in 2007 were (in rank order): Germany, United States, Spain, India and China.

Considerable wind speeds also occur across water bodies, in particular the North Pacific and Atlantic oceans. Since most of the world's population lives near oceans, wind farms near shorelines with strong offshore and onshore breezes could produce a significant amount of electricity (along with tide generators).

On land in the USA the major wind corridor is the Great Plains, what was once known as "The Great American Desert" in pioneer times. This primarily includes the states of North Dakota, South Dakota, Nebraska, Kansas, Oklahoma and Texas, and also extends into the states west of these up to the great mountains west, including eastern Montana, Wyoming, Colorado, and New Mexico. There are also considerable wind resources in eastern and southern Minnesota and the entire state of Iowa, diminishing south through Missouri and east through southern Wisconsin and northern Illinois, Indiana and Ohio. Parts of New York and the New England states also have considerable wind. Add to that potential the winds along coastlines and across the Great Lakes. Finally there are the higher elevations of mountains, notably the Appalachians and the mountains of the western US, including Alaska.

Wind Power Economics

In 2005 the US produced 4.062 trillion kWh from the following sources: coal 49.7%, nuclear 19.3%, natural gas 18.7%, hydroelectric 6.5%, petroleum 3.0%, other 2.9% In terms of megawatts (MW) the US wind power capacity in 2005 was 8,149 MW, in 2006 it grew to 11,603 MW, and in 2007 it reached 16,818 MW. While wind power is growing in the US, in 2008 it supplied 48 billion kWh of electricity, still only about 1% of the nation's total electrical production.

The Department of Energy (DOE) estimates that wind power could supply the US with 100% of its electricity, just from the Great Plains wind corridor or from offshore wind farms alone. According to the "Pickens Plan", a $10 billion wind farm with 2500 generators can supply enough energy for 1.3 million homes, and that for $1 trillion the Great Plains wind corridor could supply 20% of America's electricity. That would be about 250,000 generators to supply 130 million homes.

Electricity from wind is becoming more economical. While the construction cost for wind power is $1.5 to $2 million per megawatt (but dropping), compared $800,000 to construct a natural gas powered plant, there is no fuel cost and maintenance costs are minimal.

Connecting wind farms to the electric grid presents some problems. Wind power is intermittent - the wind doesn't always blow when electricity is needed most, and sometimes it blows when demand doesn't need it. Therefore it is not currently a reliable "base load" power source, one that runs continuously to meet a given part of a region's demand, like coal, nuclear and geothermal plants. Neither can it always be quickly ramped up and down on demand as a "peak load" source, like hydroelectric dams (and natural gas or petroleum plants) can. Since the electric grid is a transmission system without storage, "surplus" wind power has nowhere to go.

However, interconnecting enough wind farms over a broad enough area would mitigate wind power's fluctuation, because the wind will almost surely be blowing somewhere. This would make wind power a more reliable peak load source, offloading the necessity to have natural gas and petroleum plants for that purpose, and according to some studies it might even eventually become a base load power source. New forms of "grid energy storage" (e.g., charging batteries, converting it to kinetic energy in flywheels, etc.) could store surplus off-peak electricity from wind as well as other power sources.

In addition to using it as a "utility level" power source, wind power has great potential as a small-scale decentralized off-grid source. These typically don't connect to the power grid, but charge batteries. For example, small wind turbines designed for the rooftops of individual buildings are already on the market.

Solution Summary

Therefore:

In places with high average wind speeds use wind power to produce electricity. In large open areas construct wind farms, and connect enough of them to the power grid to be a viable peak load - if not base load - power source, supplanting the necessity to use petroleum and natural gas plants for electricity. At individual building and facility scales, store electricity in batteries from small wind turbines.

Successor Patterns

Where wind farms share space with agriculture, place turbines where farm equipment can pass between them in multiples of their widths - Wind Turbines Spaced For Crops . Whether electricity from wind farms are locally available or not, Small Wind Turbines can supplement the electrical needs of individual buildings and to charge batteries, e.g., for electric and hybrid-electric vehicles. . . .


References/Sources

  1. Wind power at Wikipedia.
  2. Wind farm at Wikipedia.
  3. Wind speed maps produced by the 3Tier Group.
  4. Pickens Plan

Author/Date

Gary Swift, 07 November 2008.
Last updated:

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