Wind Power

Wind is one of the cheapest, inexhaustible and sustainable forms of renewable energy. It does not produce emissions that contribute to the Greenhouse Effect and produces electricity of a quality which can be put into our electrical systems and used for everyday use.

Worldwide, there is over 10,000 MW generated and more than 50,000 operating wind turbines. It is one of the fastest growing energy sources in the world in terms of installations. Yearly investment in wind energy now exceeds many billions of dollars worldwide driven primarily by the dramatic drop in prices of wind turbines over the last ten years and the maturity of the technology.

The UK has the largest potential wind energy resource in Europe due to our physical location on the edge of the continent. However we currently get less than 1% of our electricity from wind. There is the potential for wind to provide 10% or more of our power requirements over the next twenty years.

A wind turbine is a machine that takes kinetic energy in the wind and converts it to electricity through the action of blades connected to a generator. The power in the wind is proportional to the cube of the wind speed. If the wind speed is doubled, the power goes up eight fold. However, due the physics of the technology the wind generator can never fully utilise all of the air flow due to the need to carry the air past the turbine.

Wind turbines come in a number of different types. The most common turbines look like big standard household fans, where the blades turn on an axis which is parallel to the ground. Such turbines turn to face the wind automatically. A wind turbine usually has three or less blades and is between thirty and sixty metres in diameter. The amount of power generated depends on the size of the blades and the swept area. The turbine blades are attached to the hub which is attached to the gear shaft inside the generator which then generates electricity. Typically, electricity from these turbines cost between 3p/kWh and 10p/kWh depending on scale, location and contracting period.

Other turbine types are similar to the spinning roof ventilators which have the blades spinning on a vertical axis, though these are much less common as they have proved to be less efficient.