Wind Power Discourse - Overview

Wind power is an environmentally clean, economically competitive, and publicly supported form of electricity generation. Individuals, farmers, schools, communities, businesses, and utilities around the world are erecting wind turbines. Wind power can play a major role in diversifying the world’s energy portfolio and reducing air pollution and greenhouse gas emissions.

Wind power is technically converted solar power. The sun heats land masses and oceans at differing rates. This causes portions of the atmosphere to warm differently and as hot air rises, atmospheric pressure causes cooler air to replace it. The resulting movement in the air is wind. 

The kinetic energy of wind is converted by turbine blades which drive a generator to produce electrical energy. Wind power can be harnessed using turbines grouped together on wind farms, on shore or off, for large-scale production. Wind power generation varies in size from small generators which produce sufficient electrical power to accomplish a specific task, such as pumping water, to wind farms which can generate power on the same scale as traditional electrical generation.

While wind power’s history reaches back into 7th Century Persia, where it was used to grind grain, and has been used throughout history to accomplish similar tasks. Today it relies on more modern technology to create megawatts (mW) worth of electricity per turbine.

Technology plays an important part in integrating wind into the current electricity system. In an interview with IEEE, Windlogics CEO Mark Ahlstrom, explains how weather forecasting can play a significant role in providing important information in scheduling wind energy with the rest of a utility’s system. For more on weather forecasting, please see the IEEE discourse on Earth Observation.

A 2006 symposium “Wind Power: Technology, Economics, and Politics” highlighted several key topics of interest including wind variability. The intermittent nature of wind makes reliability and storage of wind energy an important issue. Utilities must maintain sufficient power to meet customer demand plus an additional reserve margin. Although the wind is variable and at times does not blow at all, fluctuations in the output from wind farms can be accommodated within normal operating strategies. A traditional plant operating as a spinning reserve enables supply to meet demand when turbines aren’t spinning.

The capacity of the transmission grid to deliver wind energy to customers has been identified as one of the biggest constraints on wind energy use in the U.S. Often areas of high wind which are best suited as sites for wind farms are not located near demand centers, necessitating long distance transmission, resulting in a loss of power. The installation of lines and substations in remote areas also raises the cost of wind energy.

According to the Global Wind Energy Council, there is now over 59,000 MW of installed wind capacity in the world. Many countries around the world have been active in developing wind power, especially in Europe. Wind energy in Germany and Denmark has a 20% penetration level. From year-end 2000 to 2005, the U.S. wind industry has grown at an annual rate of 29%. Worldwide growth has seen a similar trend, growing an average 30% per year over the last ten years. In contrast, generation from coal and nuclear have only grown about 1.5%, showing that the installation of these forms of generation have fallen into disfavor in much of the world.

In North America most of the development is onshore, which is about half as expensive as building offshore. This is easily contrasted with Denmark, where 13.6% of its installed wind energy capacity is off-shore.

Between 2003 and 2030, there is a projected increase in demand of 71%, driven strongly by development in India and China. Traditional methods of energy generation all have serious questions associated with them. It is possible that oil production will be on the decline due to supply. Coal fired electrical generation is responsible for a great amount of dangerous pollution, and is a major culprit in the anthropogenic acceleration of climate change. Supplies of natural gas are relatively unknown, and wells may stop producing without significant warning. Nuclear energy is considered dangerous from an operational, and security standpoint by many nations and interest groups.

Large hydro-electric dams are clean, but often require the flooding of pristine natural areas. While wind energy has its own series of questions (which are included in this discourse), it does not share the same kind of uncertainty in supply, or the same scale of environmental effects as many current forms of production.

There are many costs associated with the siting wind turbines. Some of the associations are real, others are based on isolated events. Still other costs are entirely imagined. People faced with the installation of wind turbines near where they live often have many of the same concerns. Safety. Noise. Shadow and flicker, as well as light pollution from aircraft warning signals. The tourism industry fears that wind turbines interrupting scenic vistas will result in a loss of business. Commercial fisherman are concerned that offshore development will scare away fish, and interfere with their lines and equipment. Siting issues, real and imagined, can be described as Not In My Back Yard, commonly known as NIMBY arguments.

NIMBY arguments are not by definition bad arguments. If a wind turbine is improperly placed, it has the potential of causing problems for those who live around them. Additionally, while many people find the sight of turbines on the horizon pleasing, others do not. Any wind energy development must answers questions regarding environmental and wildlife impacts. The question again rises on whether or not the benefits are worth the sacrifices.

Technology can provide the answer to many siting issues, either through a change in turbine design, or by assisting planners with choosing proper locations. For instance, 3D modeling of an area can show a site designer where shadows will fall, and estimate the visibility of a turbine in the distance, in different lighting conditions.

Around the world electrical power comes mostly from generation through fossil fuels, large (dam based) hydro power, and nuclear power. To a smaller extent, biomass, wind, solar, and small hydro-electric generation contribute to the worldwide supply. The burning of fossil fuels, primarily coal and natural gas, has severe environmental consequences. Coal has the highest carbon intensity of the fossil fuels, which means that electricity generated from coal (the largest source of electricity in the U.S.) releases the most CO² (carbon dioxide) per kilowatt hour (kWh). CO² is a greenhouse gas that is thought to contribute to the acceleration in climate change. In 1999, there were 2,245 million metric tons of CO² emissions released into the atmosphere from the generation of electric power in the United States alone. In addition to the release of CO² and other greenhouse gases, electricity production from fossil fuels also contributes to acid rain, smog, ground level ozone and airborne particulates, as well as most of the mercury that has infiltrated our food chain. Wind power can play an important role of achieving the goal of a cleaner, more sustainable energy portfolio by displacing the pollution of other sources with clean generation.

One important environmental and siting issue for wind turbines is their effect on wildlife. Due to an abnormally high number of bird fatalities at the Altamont Pass Wind Resource Area (ARWRA) in Northern California, bird mortality became an environmental concern with wind turbines. The 5,400-turbine project in Altamont killed at estimated 800 to 1,300 birds a year. This prompted many studies on avian mortality due to wind turbines. Studies have since revealed that the bird mortality rate seen at Altamont is unusual, and can be attributed to technology used during construction and poor site selection. It lies along the path of a major migration route, and in an area where many raptors nest and hunt. For all combined species, data collected in the United States outside of California revealed an average 1.83 avian fatalities and 0.006 raptor fatalities per year. This compares favorably with mortality rates caused by window strikes, and domesticated cat depredation, which potentially are responsible for up to one billion fatalities per year.

A less understood phenomenon is bat fatalities due to tower and turbine blade strikes. In 2003, more than 2,000 bats were killed at a 44-turbine project in Thomas, West Virginia. Biologists have theories, but no consensus on what causes bats to fly into towers and turbine blades.

While wildlife interacting with wind turbines is an important issue, it is manageable through siting and technology, the key is to make sure it is managed. The argument against wind energy due to avian mortality is put into context by the Audubon Society, which states that global warming and its concurrent loss of habitat is the greatest threat to wildlife today. Wind energy generation’s potential in displacing greenhouse gas emissions makes it acceptable in this context.

As wind power education has improved, there has been a growing acceptance of the technology. According to a May 2005 poll conducted by Yale University , 87% of Americans support expanding wind farms and 86% want to increase funding for renewable energy research. In a poll by the Danish Wind Energy Association, they found that 91% of the population is proud of Denmark's wind industry. Denmark already has 20% of its installed capacity as wind energy.

United States President George W. Bush recognized the potential of wind power in a 2006 speech, stating that wind power could supply up to 20% of the nation’s energy needs. The American Wind Energy Association, U.S Department of Energy , along with the National Renewable Energy Laboratory, committed on June 5, 2006 to develop a plan focused on providing up to 20% of the United States' electricity from wind.

One driving factor in the increase in wind power has been its increasing economic feasibility. This can be attributed to better technology in generation and wind prediction, as well as policies that have helped wind energy develop such as subsidies and tax credits. One of the policy leaders is Denmark, which is not only a leader in percentage of installed capacity, but in wind energy technology, and turbine manufacturing. Its aim is to become the “Wind Power Hub” of the world. Other governments encourage wind energy with subsidies and tax breaks. For instance, in the United States, a renewable energy tax credit was recently renewed in the United States Congress. The necessity of renewalcauses what is often called a “boom bust cycle” in wind development, because the tax incentives can’t be counted on by developers and operators of wind farms.  When the credit is in effect, there is a boom, when it is not, a bust. European countries such as Germany and Spain have had great success with wind power largely due to their long-term public policy supporting its development.

 As wind power continues to grow, it will face both technical and policy challenges.

A major technical challenge will be the infrastructure necessary to utilize wind power. The question, “What do we do when the wind stops blowing?” needs to be answered. Without a solution for intermittent production, wind power will never become a primary source of electricity and permanently replace other more polluting methods. See the Technology section for more information on what we can do when the wind stops blowing.

The other major challenge wind energy presents, is the challenge of public acceptability.  In general, people do not object to wind power untl thhe turbines are erected where they can see them.  Wind energy either needs to change its physical attributes, or become the best option in a world of energy insecurity.

This discourse on wind energy is intended to spark informed discussion so that the positives and negatives of wind power can be examined freely and dispassionately, and to give the IEEE community a chance to see the issues and apply their expertise at solving them. Please join in the discussion - or start your own by visiting the IEEE Sustainable Development Society's message board.