This summary covers the principal findings of an analysis of electricity generation from all the UK wind turbines farms which are metered by National Grid, covering the period from January 2013 to December 2014.
The analysis shows:
- Monitored wind turbine output (as measured by the National Grid) increased from 5,894MW to 8,403MW over the period.
- The average capacity factor of all monitored wind turbines, onshore and offshore, across the whole of the UK, was 29.4% in 2013 and 28.8% in 2014.
- The monthly average capacity factor varied from 11.1% (June 2014) to 48.8% (February 2014).
- The time during which the wind turbines produced less than 10% of their rated capacity totalled 3,278 hours or 136.6 days over the two year period.
- The time during which the wind turbines produced less than 5% of their rated capacity totalled 1,172 hours or 48.8 days over the same period.
- Minimum wind turbine outputs averaged 132MW (1.8% of capacity) in 2013 and 174MW (2.1%) in 2014 as measured over 30 minute intervals.
- Variations in output of 75 to 1 have been observed in a single month.
- Maximum rise and fall in output over a one hour period was about 1000MW at the end of 2014 with a trend increase of about 250MW per year as measured over four years.
- There is no correlation between UK wind turbine output and total UK electricity demand, with output often falling as demand rises and vice-versa.
The conclusions to be drawn from the analysis are that the increase in nominal capacity:
- Does not increase the average wind turbine capacity factor.
- Does not reduce the periods of low (less than 10% of installed capacity) or very low (less than 5%) output.
- Does not reduce intermittency as measured by average monthly minimum output
- Does not reduce intermittency or variability as measured by maximum rise and fall in output over one hour period
- Does not indicate any possibility of closing any conventional, fossil-fuel power stations as there is no correlation between variations in output from wind turbines and demand on the Grid.
Therefore, based on the above, there is no case for a continued increase in the number of wind turbines connected to the Grid, or for the associated subsidies for wind energy, since this is an ineffective route to lower carbon dioxide emissions.
Download original document: “Intermittency of UK Wind Power Generation 2013 and 2014”
This article is the work of the author(s) indicated. Any opinions expressed in it are not necessarily those of National Wind Watch.
|Wind Watch relies entirely
on User Funding