How many acres of trees would need to be planted in order to have a steady supply of bioenergy feedstock for a power plant?
A rough “rule of thumb” based on recent experience is that it takes a little under 1000 acres (400 hectares) of poplar (grown as a short-rotation crop at a usable yield of 5 dry U.S. tons/acre, or 11 metric tonnes/hectare) to supply an electric power plant with a capacity of one megawatt (1 MW). A typical small biomass-fired power plant (25 MW) with 80% availability (i.e. actually operating 80% of the time) would produce about 175 million kWh per year, or approximately the electricity needs of 25,000 people. The required 25,000 acres of land (about 10,000 hectares) would occupy about 2% of the total land area within a radius of 25 miles (40 km). These calculations are based on a 30% conversion efficiency from heat to electricity, and an energy content for dry poplar wood of 17 Btu/U.S. ton (19.7 GJ/metric tonne). [Source: Walsh, M.
