Coal-fired power plants go green using wood as fuel

(The Boston Globe, November 04, 2013)

Some coal-fired power plants have started to add sawdust and wood scraps to their coal to cut their carbon dioxide output. Apart from emissions improvement benefit there is also an economic benefit, because the wood is cheaper than coal. Unlike wind or solar power electricity from a boiler, burning wood is easy to schedule and integrate into the grid. But co-firing has its drawbacks. In some cases, there is simply not enough wood. The larger mass of wood compared to coal is an issue, too. A pound of wood can produce only about two-thirds as much heat as a pound of coal, and it is a lot bigger. To produce the same amount of energy, companies must enlarge fuel-handling systems. And coal-fired plants are not used to handling fuel that can rot.