Inaccurate report disregards facts of wind energy
By Julian Scola, EWEA Communication Director
A report published in Britain has claimed that ‘wind power is expensive and yet is not effective in cutting CO2 emissions’ and that ‘there is no economic case for wind-power’. The report has been the jumping-off point for sensationalist articles in UK media claiming that wind power is ‘unreliable and requires conventional back-up capacity’ by conventional gas-fired generation, which can emit more CO2 than the most effective gas turbines running alone, and even headlines like “Wind farms cause greater pollution”.
The report, entitled ‘Electricity costs: the folly of wind power’, produced by Civitas, has been roundly criticised for inaccuracy, non-peer-reviewed and biased research, and failing to understand how a modern electricity grid works. The report is based on research by Colin Gibson. According to RenewableUK, he makes assumptions that “significantly inflate the cost of energy from wind”. Also cited is Dutch physicist Dr. Kees le Pair, a long-time critic of the wind industry and author whose work is not peer-reviewed. The report is written by Ruth Lea, a “prominent critic of climate policies (particularly the promotion of renewables)”, according to the Guardian.
Dr. Gordon Edge, RenewableUK’s Director of Policy, said “Mr. Gibson’s assumptions, upon which Ms. Lea relies, are outliers to the mainstream of analysis in this area, to put it mildly. Dedicated OCGT (open-cycle gas turbines) plants are not required to provide back-up for wind. Instead, wind can be integrated into our existing electricity system to act as a fuel saver, enabling us to harness the weather when it’s available. Some additional investment is required, but credible analysis puts the cost at one-sixth of Mr. Gibson’s inflated claims even with wind providing two-thirds of our power.”
Nick Molho, WWF’s head of energy policy, cites a report from Bloomberg that shows “the best wind farms in the world already produce power as economically as coal, gas and nuclear generators; the average wind farm will be fully competitive by 2016”. WWF themselves see a reduction in the amount of gas back-up plants by 50% if there is “greater interconnection” with Europe.
Dr. Robert Gross, of the UK Energy Research Centre has found it “disappointing that Civitas has chosen to disregard the large body of analysis that indicates that the costs and impacts of intermittency are modest and that wind is an effective fuel saver. There is of course a legitimate debate about the cost and feasibility of the 2020 target for renewables, about which renewables deserve how much support, how best to deliver such support and the role of nuclear, carbon capture and other supply options. This debate is not well served by reporting which ignores the findings of a large body of credible, peer reviewed and professional analyses and selects extreme estimates which have not been peer reviewed, do not emerge from credible engineering/economic simulations or models and are widely out of step with the scientific consensus.”
The Civitas-report, by setting the discount rate as high as 10%, overestimates the impact of investment costs and underestimates the impact of fuel costs on cost-of-energy.
It also mainly cites anecdotes and second hand sources instead of primary sources. (Example: ‘BBC weatherman Paul Hudson, who wrote in January 2011′, etc.)
This report, in my opinion, is just a FUD exercise.
Large energy suppliers say that ‘back-up’ is essential for wind. E.On annual report (circa 2005) said that they did could not rely on wind for more than 8% of their power. The CEO of Centrica says that ‘back-up’ for wind is needed and ERCOT the Texas authority says that they only rely on wind to supply 8.7% of demand.
Wind enthusiast may ‘chunter on’ about interconnectability but in the real world, engineering constraints mean that wind power is an adjunct to a reliable supply. Mr Hugh Sharman got it about right when he said wind power in the UK should not exceed 10,000MW. (Institution of Civil’s Proceedings Nov2005). Above that figure wind could not easily be incorporated into the system.
The C O2 emission sums are quite simple. Wind operates at between 25% and 30% of its rated capacity. Above those figures ‘back-up’ is needed to make 100% i.e. 75% to 70%. If you are lucky you use hydro, but in most cases fossil fuel ‘back-up’ is needed. The type of plant that can ramp up and down quickly to match the vagaries of wind is gas. A combined cycle gas turbine running full time produces about 0.4t of CO2 per MW. However, when a gas plant is run as ‘back-up’ it runs inefficiently and produces about 0.6t of CO2 per MWh. This means that used 70% of the time the gas plant produces 0.6x 0.7 =0.42t of CO2. i.e. the essential ‘back-up’ for wind means that wind power does little or nothing to cut CO2 emissions!
The analogy of fuel used a car running at constant speed on the motorway compared to a car running stop/start in town hold good. My car will travel 100 miles on a motorway at 43mpg but in town gets only 29mpg. I.e. it uses 50% more fuel to the mile in town. Gas turbines are like that too. In a stop/start regime they use 50% more fuel to the MWh, since the heat part to the generating system does not come into operation until the plant is ‘ramped up’ to full heat (takes say, an hour)