Wind
Print this page
The most common design of a wind turbine is three blades mounted on a on a tall shaft, which is free to rotate into the wind driving a generator to produce electricity (or in some instances pump water or heat water). Alternatively, vertical axis wind turbines spin on a vertical axis and so are not sensitive to wind direction, but have generally lower output. Once installed, generates no CO2 emissions.
Types
- Micro-wind turbines for mounting on buildings
- Medium-large scale, freestanding
- Output from 500W to 6MW per turbine
Other components An inverter to convert DC output to AC for grid connections Electricity meter that allows electricity export to grid Battery if not grid-connected
Typical saving
Zero carbon renewable energy source. A 2-5kW turbine with a good wind regime could generate all of the electricity for an average household over a year . Varies significantly. Large wind farms are expected to contribute significantly to UK renewables andCO2 targets.
Indicative cost
£2,500 to £5,000 per kW installed for small/micro turbines. Around £1m per MW peak output for large wind farms.
Main issues affecting feasibility
- Wind speed: A small reduction in wind speed has a large impact on power output. Speed varies a lot with location, and is difficult to predict in urban areas. Average speed should be at least 4m/s, preferably over 7m/s.
- Ecology: potential impact on birds should be assessed.
- Visual impact: may not suit conservation areas. Flicker caused by shadows of the moving blades also an issue.
- Noise and vibration: can be an issue, careful design can mitigate impact.
