The Renewable Energy Foundation, an anti-wind body, has complained again about payments made to wind farms when the National Grid is facing an inability to ensure that all wind electricity can be used. In March 2014, the Grid made payments of about £8.7m to wind operators. REF portrays this as part of a ‘steadily increasing trend’.
It may be useful to throw some extra facts into the ring.
a) During March 2014, wind supplied about 2 TWh of the UK’s total need for electricity. The percentage of total wind output that was not used was about 5%. This was a high figure for the UK: for the first quarter of 2014 as a whole, the figure is about 1.2%. January and February saw constraint payments for wind output of approximately 0.5% of the electricity generated.
b) There is no ‘steadily increasing trend’ over time. March was relatively high, February very low. (And February’s wind power output was one of the highest ever monthly figures). In the four most recent six month periods recorded by the National Grid, the percentages have been 1.4%, 2.1%,0.9% and 0.3%. (These figures are from April 2011 to March 2013).
c) REF complains about industry behaviour, saying it charges too much money for agreeing to curtail output. The average charge was about £80 per MWh in March, well down on typical figures for previous years. And REF may not be aware that National Grid payments for curtailment are usually the outcome of auctions. The price isn’t set by the wind farm operators.
d) Lastly, REF ignores the real problem, which isn’t the wickedness of farm operators or the fickleness of the wind. It’s the lack of reinforcement on the pylon lines from NW Scotland. But by late 2015 the improved line from Beauly to Denny will remove much of the constraint on wind farm output in northern Scotland. In the meantime, probably including last month, the continuing construction work on the line (which already carries electricity), means that more curtailment than usual needs to take place.
As always, the UK is coping well with the variable nature of wind power and curtailment costs add very little to the average bill. My estimate is that wind curtailment has cost a domestic customer about 25p a year.