Electricity From Trees

Some existing coal fired power plants or new power generating plants could convert to wood waste for fuel instead of coal.  Wood is a renewable energy source and is carbon neutral. 

A New Hampshire utility has converted a coal fired boiler to wood chips.  The boiler will drive a 50 megawatt electric generator.  Air emissions will be reduced by 380,000 tons.  www.renewableenergyaccess.com/rea/news/story?id=46743
Whole-tree wood chips and other low-grade woods — often referred to as “biomass materials” — are natural byproducts of responsible forestry and land management practices. Generally, whole-tree chips are produced from trees unsuitable for use in lumber or paper mills, or from the tops and branches of trees harvested for lumber. Other clean wood products, such as wood residue from sawmills, are also suitable for fuel.  Wood chips can come from waste currently left on the forest floor to decompose.  On a typical logging site, the trees are cut down, the tops are cut off and the branches are stripped. The low-grade wood includes tops, branches, rotten pieces and other leftovers: It is fed into a chipper and loaded into trucks for shipping.  Waste from wood intensive industries can also be used.  Local suppliers already in the forest wood products business can provide and deliver the fuel. 
 

Burning wood chips reduces oxides of nitrogen (NOx) by about 70 percent, mercury 90 percent, and sulfur dioxide (SO2) 95 percent. Whole-tree wood chips and other biomass materials are considered “carbon neutral,” meaning no additional net carbon is released into the atmosphere from burning wood.
   

About 1,000 wood-fired power plants were operating in the United States in past years; however, only a third of these offered electricity for sale.  The remainder were owned and operated by major industrial firms, mostly in the pulp and paper industry, which operate plants to provide in-house steam, heat, and electrical power. Most biomass installations are independent power producers and cogeneration systems with 10 to 25 megawatts capacity.  Several larger power plants (40 to 50 megawatts) were operating, and future power plants promise to be larger. Significant technical and economic benefits are associated with larger plants.