Wind News

Tuesday 23 December 2008

npower's Batsworthy Cross wind farm proposal for Devon (shown here as a photomontage) sparked off the ASA's interest in wind turbine carbon savings figures

The British wind industry has been told to use lower figures for the amount of carbon emissions being saved by wind turbines.

A long-running dispute between wind developers
and the anti-wind lobby has culminated in the British Wind Energy Association being asked to use a figure half that being claimed.

The Advertising Standards Authority has asked the wind industry body to accept a figure suggesting that wind turbines save 430g of carbon dioxide emissions for every kilowatt-hour (kWh) of power generated, compared to conventional power stations.

The BWEA had previously been claiming 860g as the right figure.

The correct answer relates to what kind of power station would be replaced by new wind turbines being connected to the grid - a figure that in reality would change on a yearly basis depending on the prices of coal and gas.

When gas is cheaper, as it was last year, the figure would be closer to 400g, the savings achieved compared to a gas-fired power station. When more coal power is used, wind turbines would achieve savings closer to 860g per kWh.

The BWEA has written to its members over the weekend to point out the ASA's latest ruling and ask developers to accept the 430g figure "for the time being".

The wind industry association told New Energy Focus yesterday that the 430g figure had been put forward by the ASA in the absence of a "better" figure. A spokesman said the figure was "way too cautious" to be on the safe side, and that the BWEA would now argue the case for a different number.

The spokesman for the BWEA said: "This is a solution the ASA accepts is on the conservative side. It's something we will have to look at again in the New Year."

Impact

The importance of the carbon savings figure comes as wind developers are seeking to persuade planners of the benefits of their projects, compared to the various negative impacts put forward by opponents.

The ASA's role in deciding what the carbon emissions impact of a wind turbine should be relates to a complaint put to the ASA by opponents of a wind farm being developed by RWE npower in Devon, and upheld by the Authority in 2007.

It had seen npower claiming in promotional material that the 18MW Batsworthy Cross wind farm would save on average 33,000 tonnes of carbon dioxide emissions a year compared to conventional power. Under the 430g figure, these savings would be closer to 16,500 tonnes.

Earlier rulings by the ASA had accepted the 860g figure used by the BWEA, but the 2007 ruling saw consultation with National Grid that questioned the comparison of wind turbines to coal power plants running over a year.

Calculations

When calculating greenhouse gas savings, the ASA suggested the comparison should reflect whichever power plants would be replaced by the wind turbines over the course of a year.

National Grid told the ASA the coal-based assumption was "inappropriate" in the calculations - but it also considered the anti-wind lobby's suggestion of a 400g per kWh figure, based on comparing wind turbines to gas power stations, as "inappropriate".

The ASA ruling in 2007 said: "They concluded that a more accurate emissions factor for wind power lay between the two figures taking account of the variations throughout the year."

The Authority has now opted for a figure close to the figure considered "inappropriate" by National Grid.

Some wind developers have previously used a range for carbon dioxide emissions, although some prefer to use a single figure, as it appears more "elegant" in their promotional material.

The BWEA told New Energy Focus that it had been in correspondence with the ASA regarding the figure, and that the work was still "ongoing".

"They have chosen this figure at their convenience, on the conservative side," the industry spokesman said. "It's a recommendation. If wind farm developers have better figures and the evidence to back it up they should use that."

Compromise

Wind developers themselves have suggested a compromise between 860g and 400g should be used.

David Walker, head of grid and regulatory affairs at Flintshire-based West Coast Energy, which is currently developing a portfolio of around 500MW of wind farms, suggested that the carbon savings figure should be around 630g per kWh at the moment.

Mr Walker said: "What we suggest is that you take an average of the annual generation - not including nuclear, since we do not go up against nuclear power - and that for fossil fuel power stations would give you a 630g figure. It's just an indication, but that's coming from the Directory of UK Statistics."