Windpower

What is it?

Windpower is a renewable energy resource, in which turbines harness the energy contained in moving air to generate electricity.

How does it work?

Wind turbines can be classified into two main types – large grid connected machines (>200kW) and smaller stand alone turbines (50W to 25kW).

Wind turbines usually have 2-3 propeller-like blades to capture the winds energy. These blades are mounted on a rotor (building mounted turbines typically have a rotor diameter of 1.5-2m). Incoming wind creates ‘lift’ and ‘drag’, similar to that around an aeroplane wing, forcing the propeller-like blades of the rotor to spin.

This mechanical energy is converted to electrical energy via a generator. The electricity is then carried away by cables running underground. Wind turbines can be used as stand-alone applications, or can be connected to the grid

Turbines typically start operating at wind speeds of 4-5m/s, reaching a maximum level at 15 m/s. The performance of the turbine will be affected by a variety of factors including the average wind speed, variation in wind speed, size of the blade, height of the turbine, and the presence of obstructions.

Who is it suitable for?

Small-scale operations can be built to power facilities of any kind, for example, domestic and community wind turbines can be deployed in rural locations or on industrial estates to provide on-site electricity for houses and businesses, provided the prevailing wind conditions and location are suitable.

The benefits

• Reduced dependency on non-renewable fossil fuels
• Reduced carbon dioxide (CO₂) and associated climate change impacts
• Reduced harmful gases such as sulphur dioxide (SO₂), nitrogen oxides (NOx) and particulates
• Once installed the energy is free
• Estimated lifespan of 25 years
• Visible statement of commitment to the environment
• Ideal for use at a local level
• Well proven technology, and costs are falling due to ongoing technical improvements
• The UK has the largest potential wind energy resource in Europe

For more information see:

Centre for Alternative Technology (www.cat.org.uk)

National Energy Foundation (www.nef.org.uk)

Energy Saving Trust (www.est.org.uk)