Talk of the town：geothermal energy in our daily lives
【明報專訊】The word ''geothermal'' comes from two Greek words — ''geo'' means ''earth'', while ''thermal'' means ''heat''. It is heat generated from the Earth, a renewable resource that can be harvested for human use.
How to use it?
The Earth is divided into four layers: the crust, the mantle, the outer core, and the inner core. The temperatures of the outer and inner cores are extremely high, providing geothermal resources to generate energy. On a small scale, the heat can be applied directly for various uses in buildings, roads, agriculture, industrial plants, and even homes. On a large scale, a geothermal power plant uses heat to produce steam, which turns a turbine (渦輪發動機). The turbine drives generators and converts the power into electricity.
Who are using it?
Geothermal energy is one of the least-explored sources of clean energy in the world. Depending on the geographic location, access to geothermal energy can vary widely. It is easier to obtain geothermal energy in some regions where the crust is thinner, such as Iceland and California in the US.
The Singaporean government has been conducting studies on the development of local geothermal energy, with an aim of diversifying clean energy options and achieving the goal of zero carbon emissions by 2050.
What is renewable energy?
According to the United Nations, renewable energy is an energy derived from natural sources that are replenished at a higher rate than they are consumed. Sources of renewable energy are mostly sustainable and endless. They are also plentiful and all around us. Common examples are the sun which produces solar energy, winds which produce wind energy, water which produces hydropower, and organic materials such as wood and charcoal which produces bioenergy.
Fossil fuels that have been used to generate electricity nowadays are non-renewable resources as they are going to run out in the future. Besides, when fossil fuels are burnt to produce energy, harmful greenhouse gases such as carbon dioxide are emitted. In contrast, the generation of renewable energy creates far lower emissions than burning fossil fuels.
■Game
(Answers on next text)
(See picture 2)
Down
1. The production of electricity by using machines that are powered by water.
2. The part of the Earth that lies between the core and the crust.
Across
3. A form of renewable energy generated when we burn biomass fuel.
4. An organic material that can produce bioenergy, which is essential for BBQ.
■Glossary
harvest (v) 收穫
obtain (v) 獲得
replenish (v) 補充
harmful (adj) 有害的
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[Smarties' Power English 第386期]
