Wind energy is currently one of the most popular sources of renewable energy due to it being inexpensive, currently competing in price with fossil fuels (Kim and Dah-Chuan Lu 2010). Wind turbines function by using the kinetic energy of the wind to drive the blades of the turbine causing the generator to convert the kinetic energy into electrical energy (Mahela and Shaik 2016). Horizontal axis turbines are the most common type of turbine. Figure 1 the setup of an air turbine with the two most common type of generators these are squirrel cage induction and doubly feed induction generators, with the doubly generators being preferred due to having control of synchronous speed (Wallace 2014).
According to (Islam, Guo and Zhu 2014) in 2014 wind energy output was 280 GW worldwide. This figure is always rising with the EU demanding at least 12% of their electricity demand to be produced by wind energy by 2020 which equates to about 180 GW of power in the EU alone (Power 2016). This leads to both massive investment and growth in the industry but also scrutiny of both the positive and negative environmental impacts that wind energy has. These include the reduction of greenhouse emissions, impact on birds and bats, usage of large areas of land, social and communal implications and the immediate weather effects. The most important of these is the sole reason for the use of wind energy, to reduce greenhouse emissions. Figure 1: General set up of Squirrel cage induction