Coal's Bright Future

Sunday, Jul. 16, 2006 By THOMAS K. GROSE
BLACK GOLD: A worker in Poland, now the largest producer of coal in the E.U.
SEAN GALLUP / GETTY IMAGES
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For decades, the burning of coal to generate electricity has seemed destined for the dustbin of history. What good is a fuel that emits into the atmosphere twice as much carbon dioxide (CO2) — considered the worst of the greenhouse gases — as does natural gas? Britain, for instance, once hoped to reduce its reliance on [an error occurred while processing this directive] coal-generated power from around 32% to 16% by 2020 as part of its plan to cut carbon emissions by 60% by 2050.

And yet, by all indications, coal seems poised for a comeback. Thanks to high natural-gas prices, worries about gas-reserve levels and the security of supplies, and new "clean-coal" technologies, coal may end up as the bridge fuel of choice to keep Europe's lights burning until renewable, cleaner sources of power become feasible. Richard Budge, ceo of British coal company Powerfuel, says that "a reaffirmation of coal" is under way. Indeed, the British government last week released a report acknowledging that coal will continue providing a third of the country's electricity well into the future. A big factor is demand: global consumption of electricity is expected to double between 2002 and 2030. "World gas resources are not sufficient to meet the world's demand for energy. It can only be done with coal," insists Martin May, spokesman for Swedish power company Vattenfall.

Not that coal ever exactly disappeared. During the cold months of last winter, both Germany and Britain relied heavily on coal to meet power requirements. And coal remains a key power source in many other countries, including Poland, Israel and Spain. But coal use is on the rise, thanks largely to a building spree of coal-fired plants in China and India. World consumption jumped from 3.5 billion tons to 4.6 billion tons between 1994 and 2004.

Part of coal's appeal is relative security of supply. Most natural gas reserves are in the Middle East and Russia; the former is a volatile region, and the latter has shown a willingness to use gas as a political weapon. Coal reserves, however, are globally widespread, and 40% are found in o.e.c.d.countries. Moreover, gas reserves are estimated to disappear within 66 years, but proven, extractable coal reserves could last for up to 200. "World coal reserves are not merely abundant, they are superabundant," Britain's Clean Coal Task Group claimed in a report to the government last month. Britain's homegrown reserves of at least 1 billion tons could last for 60 years, while Germany and Poland have reserves of 6.7 billion tons and 14 billion tons, respectively.

Despite those advantages, coal is still thought of as a dirty, carbon-heavy source of fuel, unwelcome in a world concerned with global warming and the potential environmental crises it could unleash. But that dilemma may be solved by new technologies that could reduce CO2 emissions from coal to nearly zero. Coal-fired power stations using "supercritical" boilers produce hotter steam to run the turbines: 600°C compared to around 540°C in an older plant. Supercritical plants make more efficient use of the energy created by coal's combustion, so less carbon is emitted — around 25% less than the average coal plant. If biomass — an amalgamation of wood, crops, grasses, even household wastes — is mixed with the coal, carbon emissions can be cut by a further 20%. And the resulting electricity is still cheaper than gas-produced power. Supercritical — and now ultra-supercritical — boilers have an additional advantage: they can be retrofitted into older, dirtier plants. Another, slightly less efficient, way to use coal is through integrated gasification combined cycle (igcc) technology, which gasifies coal and uses the resulting hydrogen and carbon monoxide mix to spin the turbines.