106 Unit 07 | For science! Does electricity come from the wall socket? Before reading, write down as many ways of producing electricity as you can think of. Compare your notes in class. Read the text about different ways of generating energy. Answer the questions (1–6) using a maximum of four words. Write your answers in the spaces provided. The first one (0) has been done for you. READING 10 a b The energy dilemma With the ever-growing world population, demand for energy is increasing accordingly. What are the options, and what are the advantages and disadvantages of renewable vs non-renewable energy sources? In areas where there is a sufficient and powerful enough supply, hydroelectric power can be produced by capturing the energy from moving water. The main advantage of hydroelectric power is the absence of waste or pollution since there is no chemical reaction needed to produce power. Hydroelectric power has zero emissions, and water used for hydropower can be reused. Water is usually stored in a reservoir in a hilly or mountainous area and when released, it flows through a turbine, spinning it, which in turn activates a generator to produce electricity. (Another variation is to make use of water’s undammed energy such as tidal power in the sea.) Water is accumulated above the dam and released to coincide with peaks in demand. Hydroelectric power stations can quickly increase to full capacity when more electricity is needed. However, hydroelectric dams are expensive to build and can be affected by drought. There may be other impacts on the environment such as negatively changing the surroundings in areas of natural beauty. Like hydroelectric power, wind power is also pollution-free as no chemical processes take place, therefore no harmful by-products remain. Since wind will never run out, it is renewable and sustainable. This energy source harnesses the power of the wind to rotate the blades of turbines, then the energy is converted into electrical current by means of an electrical generator. Wind towers are usually built together on wind farms, some of which are offshore, often not far from the coast. Nevertheless, like hydroelectric power stations, wind farms can have negative consequences for the landscape as they are sometimes considered an eyesore2. Farming and grazing can still take place on land occupied by wind turbines, but there are concerns that wind turbine farms, particularly large ones, may negatively affect birds which are migrating. Furthermore, they can serve as a source of noise pollution for those living and working nearby. Also, consistent wind is needed for continuous power generation. If wind speed decreases, the turbine slows and less electricity is produced. Solar energy is the most abundant renewable energy source available, and its generation releases no water or air pollution. Sunlight can be directly used to create electricity using solar or photovoltaic (PV) cells. However, making a solar panel is a difficult and expensive process and the price of installation is high. It has been estimated that generating power from photovoltaic panels costs more than four times as much as coal, and more than twice the cost of wind power. Additionally, at night and on cloudy days, the amount of energy produced is seriously limited. Despite this, many people believe that solar power will eventually overtake coal as the main source of electricity. As it is a newer technology, some of the problems currently experienced with it will likely be solved over time. A more contentious form of energy is nuclear power, which originates from the splitting of uranium atoms – a process called fission. This generates heat to produce steam, which is used by a turbine generator to make electricity. As 1 kg of nuclear fuel can produce 2 eyesore: Schandfleck, unschöner Anblick Nur zu Prüfzwecken – Eigentum des Verlags öbv
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