Wind farms are created as a way of fighting climate change and promoting clean renewable energy for the world.
What makes wind farms and their suitable environment?
Calculations show that to supplant a 1 GigaWatt fossil-fuel or nuclear power plant with wind power requires a great many of even the largest wind turbines-more than 200 in the case of the biggest.
This has given rise to the well-known concept of ‘wind farms’, whether on land or offshore. The diagram shows the existing and planned wind farms in the UK, both onshore and offshore.
As well as being steadier, wind energy can be up to five times greater at heights of 50 to 80 m - the height of the turbine axis on many modern wind turbines - than at the surface. The diagram shows how average wind speeds at 50 m above the surface vary globally.
Globally, about 30% of the land surface has average wind speeds below the 5 m s-1 threshold for wind power generation. Note that average wind speeds over much of the western British Isles exceed 8 m s-1.
The economics that set the capital cost of turbines and their maintenance costs against income, together with considerable incentives in some countries, makes wind farms an attractive proposition for investment.
The more so, as land which they occupy can yield other income too, as it seems that livestock become used to whirling blades. But there is another issue regarding wind farms.
Packing turbines closely on a single wind farm is not viable - turbines slow down the wind and create turbulence on their lee sides, which can extend many kilometres down wind.
Designing the layouts of wind farms is critical, and many that you will see around the UK have relatively few turbines arranged in lines and offset to avoid downwind effects.
Both offshore and onshore installations take up much more surface area per MW of output than a simple view might suggest - they are extremely large ventures.
For instance, to supply the electricity demand of New York City using 1.6 MW turbines would require an area of 27.4 km2 - around 3.5% of the city\'s area. Hence the outcry at their impact on scenery.