This post is to provide information to people who are interested in wind energy and how it can help the UK produce greener electricity. The study referred to was carried out in 2005 so capacity factors (and the amount of electricity generated figures) for wind turbines are probably now even higher.
Work was undertaken by the Environmental Change Institute at Oxford University into the availability of wind energy in the UK in 2005. The report, commissioned by the then Department of Trade and Industry, analysed hourly wind speeds collected by the Met Office at 60 locations across the UK between 1970 and 2003.
The study used these extensive wind records to identify patterns of wind power availability across the UK. It found that:
• Wind power availability is greater during winter than at other times of the year, and is on average stronger during the day than overnight
• Wind power delivers around two and a half times as much electricity during periods of high electricity demand as during low demand periods
• the recorded capacity factor for onshore wind turbines in the UK is around 27% – this is higher than that recorded in Denmark or Germany, and emphasises the need to use UK data in wind power assessments
It also states that the most likely change in power output from a diversified wind power system from one hour to the next is less than +/- 2.5% of the total installed wind power capacity (this takes into account the power characteristics of wind turbines with changing wind speeds). Over the longer term, around 99.98% of all hourly changes in wind power output from a diversified system will be less than +/- 20%.
Wind turbines should be located in a range of locations, rather than being concentrated in one place to create a diversified system. The advantage of a diversified system over a highly concentrated system is that the wind turbines are exposed to a range of wind conditions in different parts of the UK. In effect, the impact of low wind speeds in any particular area can be smoothed by the generation in other parts of the UK.
Diversification does not imply that wind turbines have to be ‘everywhere’ – the purpose of developing a diversified wind portfolio is to ensure greater reliability and lower variability in the electricity being generated by the overall system by exposing wind turbines to different regional patterns of wind variability and availability. Significant wind developments in different regions of the UK would form part of a diversified wind power system. This illustrates the benefits of turbines being geographically widespread across the UK.