Lentis/Wind Energy

Offshore wind farm using 5MW turbines in the North Sea, Belgium

History

Besides transportation, the earliest known use of wind as an energy source was its conversion to mechanical power in Persia sometime between 1000-200BC. The converter was a vertical axis windmill that turned a millstone, which ground grains for flour production. This design was later brought to Europe possibly by the Crusaders and windmill abundance increased dramatically in the 1200s. In 1888 Charles Brush designed and built the first wind turbine to generate electricity, which was stored in batteries for his household use. The system produced about 12KW and lasted about 20 years. In 1892 Danish scientist Dane Poul La Cour came up with the first modern design of the wind turbine based on the aerodynamic principles.

Alternatives to Electricity production

Badgir in Dolatabad Gardens, highest in the world at 34m, Yazd, Iran

Historically, wind has been used in non-electricity generating technologies such as the windcatcher. Windcatchers have been used for many centuries to create natural ventilation in buildings in central Iran. The structure directs wind down into the building and pulls air out of the building from the opposite side. Inside the building there is usually a pool or a decorating water fountain. The rapid evaporation of this water due to the very low air humidity of the area can significantly cool down the building and act as a natural air conditioning system. Although windcatchers have long been forgotten to the extent that even people in Iran may not have heard of them, a comeback is possible. BBC reported a design of a zero emission home in 2007 claiming that it will set the environmental standards for all new homes in the future. One of the main components was a wind catcher for ventilation.

Benefits of Wind Energy

While environmental pollution and the emission of carbon dioxide from the use of fossil fueld constitute a threat to health, the environment and sustainable economic growth, wind energy is a source of clean, non-polluting electricity. Wind turbines cause virtually no emissions during their operation and very little during their manufacture, installation, maintenance and removal. According to the United States Department of Energy, in 1990, California's wind power plants offset the emission of more than 2.5 billion pounds of carbon dioxide, and 15 million pounds of other pollutants that would have otherwise been produced. It would take a forest of 90 million to 175 million trees to provide the same air quality. Moreover, wind energy can provide incomes for rural areas.

By 2020, taking European Wind Energy Association projections that 180GW of wind energy would be generating 425 TWh per annum, wind power will provide annual savings of:

• 215 million tonnes CO₂

• 261,000 tonnes SO₂

• 333,000 tonnes NO_x.

Technical and Environmental Issues

Supply and Storage Issues

The best option for wind is as distributed power. Electricity generated from wind power can be highly variable at several different timescales: from hour to hour, daily, and seasonally. Wind also tends to be complementary to solar. This means that wind energy is an intermittent technology that can be used only when resources are available. The intermittence of wind hinders the economic competitiveness of the resource, because instantaneous electrical generation and consumption must remain in balance to maintain grid stability.

Cost Issues

Even though the cost of wind power has decreased dramatically in the past 10 years, the technology requires a higher initial investment than fossil-fueled generators. Intermittency and the non-dispatchable nature of wind energy production can raise costs for regulation, incremental operating reserve, and could require an increase in the already existing energy demand management, or storage solutions.

Wind Turbine Technological Challenges

The engineering challenge for the wind industry is to design an efficient wind turbine to harness wind energy and turn it into electricity. The evolution of modern wind turbines is a story of engineering and scientific skill. In the last 20 years, turbines have increased in size by a factor of 100 (from 25 kW to 2500 kW and beyond), the cost of energy has reduced by a factor of more than five.

It is a big challenge to produce a wind turbine that:

• Meets specifications (frequency, voltage, harmonic content) for standard electricity generation with each unit operating as an unattended power station;

• Copes with the variability of the wind;

• Competes economically with other energy sources.

• Stands high fatigue.

Environmental Concerns

Although wind power plants have relatively little impact on the environment compared to fossil fuel power plants, the environmental issues include how the turbines appear in a landscape, the sound they make and their effect on birds and other wildlife.

• Noise

Like all mechanical systems, wind turbines produce some noise when they operate. In recent years, engineers have made design changes to reduce the noise from wind turbines.

• Visual Impacts

Because they must generally be sited in exposed places, wind turbines are often highly visible. They need to be in order to catch the prevailing wind and work effectively. Being visible is not necessarily the same as being intrusive. However, aesthetic issues are by their nature highly subjective. Proper siting decisions can help to avoid any aesthetic impacts to the landscape.

• Avian/Bat Mortality

Bird and bat deaths are one of the most controversial biological issues related to wind turbines. The deaths of birds and bats at wind farm sites have raised concerns by fish and wildlife agencies and conservation groups.

Health Concerns

It has been argued that wind turbines can have an impact on human health and quality of life. "Wind Turbine Syndrome" was first brought up as an issue by Dr. Nina Pierpont, an anti-wind energy activist. In her book self-published in 2009, she attributes symptoms including sleep deprivation, headaches, dizziness, anxiety, and vertigo to the infrasound and low-frequency noise generated by wind turbines. Proponents of wind energy such as the American Wind Energy Association (AWEA) and the US Department of Energy have countered these claims by citing studies that correlate these symptoms to annoyance and stress rather than physical health impacts. Furthermore such studies conducted by Pierpont and other opponents are case series, which provide weak evidence.

Shadow flickering has also been identified as a potential problem for those living close to wind turbines. However, minimum setback distances can be implemented to prevent this.

Public Attitudes

National opinion towards wind energy have been positive as the United States attempts to reduce carbon emissions through the increasing use of alternative, cleaner sources. A survey conducted by the American Wind Energy Association in March 2010 noted that 89% of American voters believed the nation should increase usage of wind energy. Additionally, 77% supported the implementation of a national Renewal Energy Standard (RES) that would mandate the amount of energy obtained through renewable sources.

Despite overwhelming support for the United States to switch to more renewable, green energy, the installment of wind energy technology across the nation continues to face strong opposition by people living near proposed sites. Local opposition towards wind energy can be described by an attitude known as NIMBY (not in my backyard). Nimbies are people who support a cause (e.g. wind energy), but do not want it to require any sacrifices on their part. For wind energy, these sacrifices may include the aforementioned issues in addition to other ones pertaining only to citizens living in the near vicinity to wind turbines.

Example of Nimbyism: Cape Wind

A great example of Nimbyism is Cape Wind, an approved offshore wind project located by Cape Cod. Initially proposed in 2001 by Jim Gordon and his company Cape Wind Associates, the project would entail the installation of 130 wind turbines in a shallow, high-wind region of the Nantucket Sound known as Horseshoe Shoal. The company claims that the wind farm would be capable of supplying 75% of the electricity necessary for the Cape and the Islands.

Following its proposal, the Alliance to Protect the Nantucket Sound was founded. As classic Nimbies, this group believes that the Cape Wind project has the right idea, but the wrong location. They believe that Cape Wind would be detrimental to wildlife, the economy, public safety and the scenery. Two computer generated simulations of what the proposed wind farm would look like from shore show how opposing groups can use images to affect human perceptions. Although the two images are from locations the same distance away from where Cape Wind would be, it is obvious that the subtle differences are meant to persuade the viewer one way or the other. In addition to images, both groups support their arguments with what they claim are facts. These facts are then labeled as myths by the opposing side. Some of the most heavily debated issues are the price of the electricity, the effect on marine life and the visibility of the turbines on the horizon.

Coverage of Cape Wind has not only been limited to local news and blogs, but has also been in the form of popular media. Cape Wind: Money, Celebrity, Energy, Class, Politics, and the Battle for Our Energy Future was written by Robert Whitcomb and Wendy Williams in 2008. An unreleased documentary named Cape Spin has also been produced.

Conclusions

Several lessens can be learned from the social interface of the wind technology.

• Technological path dependence. Technologies can progress and develop in one direction and that direction or path becomes the main focus of future development and alternatives get forgotten.
• Feasibility of different technologies in different parts of the world. Not all technologies are suitable everywhere. The general public has a tendency to look for or support one solution. For example, wind turbines are economically feasible in windy places andwindcatchers are only feasible in extremely low humidity climates.
• NIMBY. People may support an idea in general, but when its drawbacks directly affects them they oppose it. Most people make decisions based on personal incentives, which they place priority on over the greater good. Technologies that give personal incentives thrive, even if their effect on the environment may be negative. We see this all around the world as people or businesses make decision based on maximizing profits and ignoring the environmental effects. To be successful in saving the environment we must develop technologies that have personal incentives as well as environmental benefits.