Magazine article Management Today

Power but No Glory

Magazine article Management Today

Power but No Glory

Article excerpt

Unpopular and unfashionable coal-fired stations like Drax may be an essential part of the UK's energy needs for some time to come, says Andrew Saunders.

Make no mistake, the power station at Drax is big.

Approaching the 750-hectare site across the flat, featureless countryside near Selby, south of York, you can't miss its dozen 114m-high cooling towers dominating the skyline. On a clear day, you can see them from the edge of the Yorkshire Dales 25 miles away, billowing steam - but no lava or ash - like so many synthetic volcanoes.

Its operating stats are equally gargantuan. At full tilt, the boilers consume 36 tonnes of pulverised coal a minute, providing superheated steam at a pressure of 165bar to turn the six huge generating sets at 3,000rpm. These feed 4,000Mw into the National Grid through an array of humming transformers and crackling overhead cables. Welcome to the largest and most efficient coal-fired power station in western Europe.

All pretty impressive in a Boy's Own Book of Facts kind of way Unfortunately, Drax is best known for a rather less edifying stat that has made it a target for climate change campaigners, and put huge pressure on parent company Drax Group to do something to make the giant generator more sustainable and less of an eco-baddie in the eyes of the public.

It is the UK's single largest producer of carbon dioxide, chucking 22m tonnes of the stuff into the skies every year. No wonder protestors feel so strongly about it. However - and here's the rub - Drax is also a strategic national asset. If it were to shut down, the protesters might be satisfied, but the UK would pay a high price for those lower carbon emissions. Drax generates as much as 7% of the UK's total electricity demand, enough to power some 4 million homes, or hundreds of thousands of businesses. It's a lot of people to leave in the dark.

Then there's the energy gap: in the next decade, the UK will lose nearly 20% of its generating capacity, as the last nuclear power stations reach the end of their lives. Replacements are scheduled, but won't be ready in time. As newly appointed energy minister Chris Huhne is doubtless realising, it will be hard enough to keep the lights on as it is, without losing any more capacity - regardless of its carbon footprint.

It's a conundrum with which Drax's CEO, Dorothy Thompson, is all too familiar. 'We are the largest single-site emitter of carbon in the UK,' she admits. 'We decided quite a long time ago to reduce our carbon emissions. And if you are a coal-fired generator, there are really only two ways to do that - to improve your technology or burn something else.'

So the engineers at Drax have been busy scratching their heads trying to do both. Efforts to improve the technology have focused on achieving better controlled and more complete combustion of coal in the boiler and on fitting new blades to the steam turbines that will enable them to operate more efficiently, especially at less than full power.

All that only promises to trim emissions by a few percent. It's the boffins' efforts on the 'burn something else' front that have attracted the most interest, offering the prospect of CO2 reductions of 20% or more. Since 2004, experiments have been undertaken to figure out the best way of persuading Drax's boilers - all between 30 and 40 years old, designed to consume powdered coal - to adopt a more varied and planet-friendly vegetarian diet, in the form of plant-based biomass.

Biomass fuel can be anything from straw bales to sewage sludge, but at Drax they have been concentrating on burning straw and wood: elephant grass and willow branches, to be specific. These are reduced to a powdery mulch, before being blown into the boilers as a replacement for a proportion of the pulverised coal that would otherwise fuel the plant.

In theory, biomass - a seriously green alternative to fossil fuels - could be the answer to Thompson's prayers. …

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