A. Geothermal energy is a form of renewable energy that harnesses the heat from within the Earth. This heat is a result of the slow decay of radioactive particles in the planet''s core, a process that has been occurring since the Earth was formed. In some areas, this heat rises close to the surface, where it can be tapped to generate electricity or for direct heating applications. As a power source, geothermal energy is notable for being both reliable and producing a very low level of greenhouse gas emissions.
B. There are three main types of geothermal power plants. Dry steam plants are the oldest type, using steam that comes directly from underground fractures to turn a turbine. Flash steam plants, which are more common, pump high-pressure hot water from deep underground into a lower-pressure tank, where it "flashes" into steam. Binary cycle plants, which can operate at lower temperatures, use the hot water to boil a secondary fluid with a lower boiling point, and the vapour from that fluid drives the turbine.
C. Beyond electricity generation, geothermal energy has significant potential for direct use. Geothermal heat pumps can use the stable temperature of the ground just a few metres below the surface to heat and cool buildings with high efficiency. In some regions, naturally hot water is piped directly into district heating systems to warm homes and businesses, and is also used for industrial processes, in greenhouses, and for aquaculture.
D. The primary advantage of geothermal energy is its consistency. Unlike solar and wind power, which are intermittent, geothermal power plants can operate 24 hours a day, 7 days a week, providing a stable, baseload supply of electricity. However, the use of geothermal energy is geographically limited to areas with accessible geothermal reservoirs, which are often found along tectonic plate boundaries. While the initial drilling and construction costs can be high, the long-term running costs are low, and the environmental footprint is minimal, making it a valuable component of a clean energy future.
IELTS Practice Tests Practice Test / Part 1 #207
