Most of the world's biggest wind farms are located in the USA or China,and in fact the largest onshore farm, and the second largest wind energy project, in 2012 is in the US. It's the Alta Wind Energy Center in California, in a mountainous area of Kern County. It has around 600 turbines and serves over a quarter of a million homes.

The largest offshore wind farm, and the one serving the largest number of people in the world, is in the UK, the Array wind farm in the Thames Estuary off the Kent coast. It should have 175 (each as tall as the London Eye) turbines when all work is completed and will be able to supply energy to almost half a million households. This farm has only just gone into operation (30 Oct 2012).

As wind energy becomes more used and the technology improves, we can expect to see even bigger projects in the future, as well as small scale ones