The expanding market for wind power
It is forecast that, worldwide, the market for wind energy will continue its recent trend of growing massively (by 30-40% per annum). While much attention has been paid to the fact that China brings a new coal-fired power station online every ten days, less well known is the country’s interest in wind power: China has doubled its capacity every year since 2004.
How Wind Energy Works
Wind energy can be harvested in many different ways: with large scale wind farms featuring giant turbines, on or off shore; smaller embedded systems built in to office blocks and modern houses and domestic scale turbines (also known as ‘microwind’), often mounted to chimneys.
Regardless of the size of the turbine, the operating principles are the same: blades are angled into the prevailing wind at different degrees according to wind strength. When it reaches around 4 metres per second (mps), 30% less than the UK local average, the turbines start generating electricity.
They operate most efficiently in winds of around 15mps and have a variety of features built in, such as variable blade pitch or designed-in ‘passive stall’ which ensure the system is not overloaded by gusts or storms where speeds may be far higher.
Criticisms of wind power
Perhaps surprisingly for an inexhaustible, clean energy source, wind power has been subject to intense criticism, principally for its relatively low overall availability (turbines only work to maximum effect when the wind speed is neither too low nor too high) and therefore cannot be relied on as a sole energy source.
Increasing the efficiency of wind power
Turbine efficiency is increasing year on year, in line with new investment and research. While there is some threat to bird life, especially if turbines are located in migration paths (as has been the case in the early days of the industry), this is no greater and probably less than that posed by any tall building and power cables – both of which are far more prevalent.
Case study: Building wind farms
Vestas has installed over 35,000 wind turbines and were responsible for the turbines at the UK’s first and largest offshore wind power plant at North Hoyle in Wales. Read more about the technical advancements being made in new wind farms.