Wind

Background - 16 March, 2006
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, 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).

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

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.

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

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 Tera watt 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.

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 Tera watt 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 life cycle of a wind turbine are "paid back" after the first three tosix 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.

Installing a wind turbine

Members of Solar Generation and the local community install a 2.5kw wind turbine at a primary school.

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 skeptics 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.

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