WHY DO WE NEED RENEWABLES? – POWER PRODUCTION FROM PLANTATION FUELS
Biomass accounts for nearly 15% of world energy supplies.Inthe industrialized countries, biomass supplies about 3%, or 8 exajoules (EJ), of total primary energy.
The dominant and fastest growing use of biomass fuels in industrialized countries is for process heat and electricity.
In the developing countries, biomass fuel supplies about 48 EJ or 35% of total primary energy. Most of this biomass energy is used traditionally for domestic cooking and space heating.
However, where there are industrial and agricultural enterprises, wood, bagasse, rice hull, and other waste products are often used to generate heat for agricultural processes such as crop drying, steam to drive small-scale industrial processes, and electricity for on-site use and sometimes for off-site power sales.
The recent interest in converting biomass to electricity comes not only from its potential as a low-cost, indigenous supply of power, but for its potential environmental and developmental benefits. For example, biomass may be a globally important mitigation option to reduce the rate of CO2 buildup by sequestering carbon and by displacing fossil fuels.
Renewably-grown biomass contributes only a very small amount of carbon to the atmosphere. Locally, plantations can lessen soil erosion, provide a means to restore degraded lands, offset emissions and local impacts from fossil-fired power generation (e.g., SO2 and NOx), and, perhaps, reduce demands on existing forests. In addition to the direct power and environmental benefits, biomass energy systems offer numerous other benefits, especially for developing countries.
Some of these benefits include the employment of underutilized labor and the production of co- and by-products (e.g., fuel wood).
Nearly all of the experience with biomass for power generation is based on the use of waste and residue fuels (primarily wood/wood wastes and agricultural residues).
The production of electric power from plantation grown wood is an emerging technology with considerable promise. However, actual commercial use of plantation-grown fuels for power generation is limited to a few isolated experiences.
Wood from plantations is not an inexpensive energy feedstock, and as long as worldwide prices of coal, oil and gas are relatively low, the establishment of plantations dedicated to supplying electric power or other higher forms of energy will occur only where financial subsidies or incentives exist or where other sources of energy are not available.