The United States has a lot of federally owned land.Unfortunately, uncontrolled natural forest fires destroy largeareas in the western US every summer. In 2002, about 1,000,000acres of standing timber in national forests were consumed. Someconsideration is being given to improved management practices thatcould produce electric power from residual forest thinning.Estimate the lost energy content of burned US forests during 2002.Assuming the US average electricity demand is about 300,000 MW e ,how much forested land would be needed to produce all the country ’s power? Is this a sustainable alternative? How would you managethe forest lands needed? A few facts to consider: the totalforested area on US federal lands in the lower 48 states is about600 million acres with a standing stock density of about 100 drymetric tonnes of wood per acre. Woody plants and trees capturesolar energy via photosynthesis at an average rate of about 0.8 W/m2 , which corresponds to producing about 5 – 10 dry tons of biomassper acre annually with an average heating value of 8000 BTU/dry lb.Note that 1 acre = 43,560 ft 2 = 0.405 hectare = 4047 m 2 and theaverage heat-to-work conversion efficiency of a biomass-firedelectric power plant is about 35%.
