Wind

The UK 's first wind farm in the Irish Sea which will supply 50,000 homes with power.

Wind power, the world's fastest growing energy source, is a deceptively simple technology. Behind the tall, slender towers and steadily turning blades lies a complex interplay of lightweight materials, aerodynamic design and computer controlled electronics. Power is transferred from the rotor through a gearbox, sometimes operating at variable speed, and then to a generator (although some turbines avoid a gearbox by use of direct drive).

Wind power today

Two decades of technological progress have resulted in state-of-the-art wind turbines that are modular and rapid to install. Today, a single modern wind turbine is 100 times more powerful than its equivalent two decades ago, and now wind farms provide bulk power equivalent to conventional power stations.
By the beginning of 2004, global wind power installations had reached a level of 40,300 MW. This provides enough power to satisfy the needs of around 19 million average European households, close to 47 million people.

Offshore windpark in Denmark . Denmark is one of the leading countries in developing wind power.

As the market has grown, wind power has shown up to a 50 percent drop in production costs over the past 15 years. Now, at optimum sites wind can be competitive with new coal-fired plants and in some locations can challenge gas.

Wind power by 2020

With installed wind capacity growing at 30 percent over the past few years, it is an entirely realistic goal to for wind to provide 12 percent of the world's energy by 2020. Along the way, this would create two million jobs, and save more than 10,700 million tonnes of carbon dioxide emissions.

Thanks to continuing improvements in the average turbine size and capacity, by 2020 the cost of wind power on good sites is expected to drop to 2.45 euro cents per kilowatt hour (kWh) – 36 percent less than its 3.79 euro cents/kWh cost in 2003. Grid connection is not included in these costs, but is a factor for virtually any new energy site, not just wind.

Wind power beyond 2020

The world’s wind resources are extremely large and well distributed across almost all regions and countries. Using current technology, wind power could supply an estimated 53,000 Terawatt hours (TWh) per year. This is more than twice the projected world energy demand in 2020 - leaving substantial room for growth in the industry even decades from now. The US alone has enough wind potential to supply its energy needs three times over.

Advantages of wind:

Environmentally friendly - A reduction in the levels of climate change causing carbon dioxide emissions is the most important environmental benefit from wind power generation. However, it is also free of the other of other pollutants associated with fossil fuel and nuclear plants.

Extremely good energy balance - The carbon dioxide emissions related to the manufacture, installation and servicing over the average 20 year lifecycle of a wind turbine are “paid back” after the first three to six months of operation – which means more than 19 years of energy production at virtually no environmental cost.

Quick to deploy - Construction of a wind farm can be completed within a matter of weeks, with large cranes installing the turbine towers, nacelles (housing) and blades on top of reinforced concrete foundations.

For the same investment, wind generates 5 times the jobs and 2.3 times the power as a nuclear reactor.

Reliable and renewable resource – Wind to drive the turbines will always be free of charge, and unaffected by swings in the price of fossil fuels. It also doesn't need to be to be mined, drilled for or transported to the generating station. As world fossil fuel prices rise, so does the value of wind power, and its generating costs will only drop.

Furthermore, in larger projects, using proven medium sized turbines, an operational availability of 98 percent is consistently achieved using wind. Meaning only a two percent down time for repairs - a far better performance record than what can be expected from a conventional power plant.

Variability of wind

The variability of the wind has produced far fewer problems for electricity grid management than sceptics had anticipated. Swings in energy demand and the need to protect against failures of conventional plants actually require more flexibility of the grid system than wind power, and real world experience has shown that national power systems are up to the task. On windy nights, for example, wind turbines account for up to 50 percent of power generation in the western part of Denmark , but the load has proved manageable.

The creation of super-grids also reduces the problem of wind variability by allowing changes in wind speed in different areas to be balanced against each other.

Moving forward

Despite its recent rapid growth the future of wind power is not guaranteed. Although there is some wind power today in 50 countries, most of the progress so far has been thanks to the efforts of just a few, led by Germany , Spain , and Denmark . Other countries will need to improve their wind power industries dramatically if global targets are to be met. Therefore, the prediction of 12 percent of the world's energy from wind power by 2020 should not be seen as a sure thing, but as a goal – one possible future we can chose if we are willing.

Published by: http://www.greenpeace.org/international/campaigns/climate-change/solutions/wind