Pollution from planned wood-burning plant will be ‘like two million cars’

23 June 2013

A proposed wood-burning power station will belch as much toxic pollution into the air as two million car exhausts and put public health at serious risk, environmentalists are warning.

Controversial plans for a new £325 million plant at the port of Dundee are due to be considered by city councillors tomorrow. But critics say that hazardous emissions from the smokestack could worsen air pollution in the city, which is already at dangerous levels.

Like motor vehicles, burning wood produces tiny sooty particles and nitrogen dioxide gas, which can trigger breathing problems, heart attacks and strokes. Estimates by government advisers suggest that air pollution could be responsible for 3,000 premature deaths in Scotland every year.

The Dundee plant is one of four originally planned by Forth Energy, which brings the harbour company, Forth Ports, together with the power company, Scottish and Southern Energy. A plant at Leith in Edinburgh was abandoned after protests, a plant at Rosyth in Fife is awaiting a decision by ministers and a plant at Grangemouth in Falkirk was given the go-ahead earlier this month.

If the three remaining plants are built, they will be fuelled by importing a total of 1.7 million tonnes of wood chips and pellets every year from felling forests in North America and elsewhere. Forth Energy claims that this will cut climate pollution, but this is disputed by environmental groups.

The plants are likely to qualify for significant renewable energy subsidies from the government. They are seen by their backers as a crucial way of decarbonising the economy, but by their opponents as a dangerous mistake.

In Dundee the fiercest arguments have focussed on the health risks of the pollutants that the plant will spread over the city. Friends of the Earth Tayside and Biofuelwatch, backed by experts, have calculated that it will emit as much nitrogen dioxide every year as almost two million cars, as well as boosting particulate pollution by 70%.

They point out that Dundee’s existing 72,000 cars are responsible for the city breaching European safety limits on air pollution. To try and combat the problem, the whole city has been designated as an air quality management area.

Andrew Llanwarne from Friends of the Earth Tayside urged Dundee City Council to reject the proposed wood-burning power station. “Councillors need to seriously consider the implications of this proposal for the health of local people,” he said.

“Air pollution is insidious. We don't see it in the air that we breathe, yet it is doing serious damage to our lungs whilst the fine particulates find their way into our cardiovascular systems. People's deaths may be attributed to lung disease or heart attacks, yet it is often air pollution that has made the condition worse.” 

A report by council planners recommends that councillors approve the plant, subject to conditions. An assessment by Forth Energy concluded that 12,748 people would be exposed to nitrogen dioxide from the plant, but that the impact would be “negligible”.

Its conclusions, however, have been questioned by Ann Prescott, a retired environmental science lecturer at the University of Abertay in Dundee. She accused the company of using “guesstimates” from 1988 to make the pollution look more acceptable to politicians.

Forth Energy said that it “did not recognise” the figure of two million cars and was “unclear” how it had been reached. It would be more relevant to compare the proposed plant with other forms of electricity and heat generation, which would show significant carbon savings, it argued.

“It these plants didn’t deliver carbon benefits, we wouldn’t be building them,” said Forth Energy’s managing director, Calum Wilson. “We comply with all the current regulations and guidelines on the control of emissions.”

He pointed out that the Scottish Environment Protection Agency had not objected to the plant, and would be responsible for regulating its pollution. It would produce 100 megawatts of electricity – enough to meet the needs of 90% of Dundee households – and 30 megawatts of heat for nearby businesses. He hoped to get it up and running by 2018.

Update, 25 June 2013

Dundee City Council voted by 20 to 6 to reject Forth Energy's application for a wood-burning power plant, triggering a public inquiry.

Comments

[joerommiswrong]

Burning wood is ridiculously eighteenth century.
Here's a better solution:
Nuclear.

[Demelza]

I'm out of lgeaue here. Too much brain power on display!

[U K W]

Hiya,
Are you quite sure that the values for NOx emissions from cars are in grams, only the table in the web link seems to contain relative values - there don't appear to be any units?
You could try DEFRA's latest Emission Factor Toolkit or COPERT 4 version 10 for more up-to-date vehicle emission values.
Hope this is helpful.

[Rob Edwards]

Thanks for that information.

[Robert Palgrave]

Forth Energy says it does not recognise the figure of nearly 2 million cars calculated by Biofuelwatch for this article.

Here is the arithmetic on Nitrogen Dioxide.

Assumptions:

- Average UK car mileage: 8,430 or 13,566 km per year

(www.racfoundation.org/motoring-faqs/mobility - a15)

- Half the cars are diesel, half are petrol

- Average petrol car NOx emissions: 23 milligrams per km (with catalytic converter)

- Average diesel car NOx emissions: 31 mg/km

(www.lordgrey.org.uk/~f014/usefulresources/aric/Resources/Fact_Sheets/Key_Stage_4/Air_Pollution/26.html)

NOX EMISSIONS FOR CARS:

Assuming half the cars are diesel, half are petrol, then the average NOx per car is 27 mg/km, meaning that each car emits 27 grams of NOx per 1000 km

Driven for 13500 km, each car emits 0.37 kilograms per year.

NOX EMISSIONS FROM FORTH ENERGY’S DUNDEE BIOMASS POWER STATION:

NOx emissions from smokestack: 24 grams per second (Forth Energy’s figure from their Environmental Statement)

This is 86.4 kilograms per hour

Which equates to 691,200 kg every year (or 691 tonnes) if the power station runs for 8000 hours per year.

COMPARISON:

Dividing 691,200 kg (power station) by 0.37 kg (single car) gives the figure of 1,868,108 cars.