Biomass – the growing energy resource
Glossary
anaerobic. Requiring no oxygen.
chemical bonds. The attractions that hold atoms together to form molecules.
chloroplasts. Small organelles found in plant cells. They contain the green pigment chlorophyll which captures solar energy from the sun and is essential for photosynthesis in plants.
enhanced greenhouse effect. An increase in the natural process of the greenhouse effect, brought about by human activities, whereby greenhouse gases such as carbon dioxide, methane, chlorofluorocarbons and nitrous oxide are being released into the atmosphere at a far greater rate than would occur through natural processes and thus their concentrations are increasing. Also called anthropogenic greenhouse effect or climate change.
fossil fuels. Carbon or hydrocarbon fuels, derived from what was living material, and found underground or beneath the sea. The most common forms are coal, oil and natural gas. They take millions of years to form. Their energy is only released upon burning, when the carbon and hydrogen within them combine with the oxygen in air to form carbon dioxide (CO2 ), or carbon monoxide (CO) and water (H2O). Other elements within the fuels (such as sulfur or nitrogen) are also released into the air after combining with oxygen, causing further pollution with SO2 and nitrogen oxide gases. In the case of coal, ash particles are also a problem.
hydrocarbon. Compound containing only the two elements, carbon and hydrogen.
kilowatt, megawatt, gigawatt. The basic unit of power (the rate at which energy is used) in the metric system is the watt (W); a kilowatt is 1000 watts. A watt is a very small amount of power and in most mechanical applications we count power in kilowatts. A kilowatt is about equal to the heat energy put out by a single bar radiator, and is also about equal to the power expended by a person running up stairs. A car engine typically produces 50 to 100 kilowatts.
When we consider power generation, we use larger units. A megawatt is 1,000,000 watts or 1000 kilowatts. A typical coal-burning power station produces about 1 gigawatt (1000 megawatts) of power.
photosynthesis. The biochemical process in which green plants (and some microorganisms) use energy from light to synthesise carbohydrates from carbon dioxide and water.
Posted June 1999.