Green Energy - IELTS Reading Answers & Explanations
From Barrons IELTS Practice Exams General Training Reading Test 6 · Part 3 · Questions 28–40
Reading Passage
Read the text below and answer Questions 28–40.
Green Energy
As energy prices rise and the effects of greenhouse gas emissions become more widespread, people everywhere are becoming increasingly concerned about using fossil fuels. More and more people are turning to so-called “green technologies” as a way to reduce dependence on nonrenewable fossil fuels. The ideal alternative energy source would be sustainable (the supply will not be exhausted), clean (no emissions), and reliable. The three most popular alternative energy sources are geothermal power, solar power, and wind power.
Since geothermal energy taps heat from the earth, its resources range from water found just below the surface of the earth, to hot water and hot rock found a few miles below the surface, to even deeper rock of extremely high temperatures. In a process similar to drilling for oil, wells as deep as a mile or more can be drilled into underground reservoirs to tap steam and hot water that are used to run turbines and create energy. Power companies can then transmit this energy over power lines.
Geothermal power on a smaller scale can be used for heating and cooling houses or commercial buildings. Geothermal heat pumps, also known as ground-source heat pumps, rely on the fact that the earth beneath the surface remains at a relatively constant temperature throughout the year. Like a cave, the ground is warmer than the air above it during the winter and cooler in the summer. The geothermal heat pump transfers the heat stored in the earth into the building during the winter, and transfers it out of the building and into the ground during the summer. The ground, in other words, acts as a heat source in winter and a heat sink in summer. While geothermal heat pumps are an emissions-free and reliable source of energy, the biggest disadvantage is that such systems are expensive to install.
Solar energy has come a long way from the clunky boxes of the 1970s. Today, solar energy is commonly collected by sleek and efficient photovoltaic (PV) panels. The photovoltaic cells convert sunlight directly into electricity and are made of semiconductors such as crystalline silicon or other thin-film materials. The benefits of solar power vary according to how much exposure a given building has to the sun. However, one does not need to live in the desert to take advantage of solar power. Cloudy Germany is the worldwide leader in the use of solar power.
Solar power is not as pricey as geothermal power, but having a panel professionally installed can still be costly. Some enterprising home-owners reduce the initial costs by purchasing inexpensive kits and setting up the system on their own. The biggest disadvantage of a solar power system is its dependence on the amount of sunlight collected, but some cutting-edge panels can generate energy even in the rain.
Wind power is created when wind is used to generate mechanical power or electricity. Most wind turbines convert the wind’s kinetic energy into mechanical power. The wind turns the blades, which spin a shaft connected to a generator. A generator then converts this mechanical power into electricity. A group of wind turbines can produce electricity and feed it into the utility grid, where it is sent through transmission lines to homes and businesses. Like solar and geothermal energy, wind is a renewable resource that produces no emissions.
Small wind energy systems can be used by homes, farms, or communities. Such systems can be connected to the larger electrical grid or used for stand-alone energy generation—a particularly attractive option for anyone living far from power company lines. A grid-connected wind turbine can reduce one’s reliance on the power company for electricity. If the turbine cannot deliver the needed energy, the power company then makes up the difference. However, in order to take advantage of wind energy, a turbine must be in an area with average wind speed of at least 10 miles an hour, and such systems can be very expensive.
Whether a given home or business uses wind, solar, or geothermal power depends on a variety of economic and environmental factors. However, experts agree that investing in alternative energy now—whether by individuals or power companies—will pay dividends in the future.
Questions
Questions 28–30 Summary Completion
Complete the summary below. Choose NO MORE THAN TWO WORDS from the passage for each answer.
These days, people are interested in reducing their consumption of 28. They are looking at sources of 29 to supply their power needs. People want sources that are 30, do not cause pollution, and can be consistently depended on.
Questions 31–33 Three Choices
Choose THREE answers from the list below.
Questions 34–36 Three Choices
Choose THREE answers from the list below.
Questions 37–40 Four Choices
Choose FOUR answers from the list below.
Answers & Explanations Summary
| # | Answer | Evidence | Explanation |
|---|---|---|---|
| Q28 | fossil fuels | More and more people are turning to so-called “green technologies” as a way to reduce dependence on nonrenewable fossil fuels | Excerpt/Passage Explanation: The passage states that an increasing number of people are using green technologies so they do not have to rely as much on fossil fuels. Answer Explanation: The answer means natural energy sources like coal, oil, and gas that come from deep inside the earth and cannot be remade quickly. Reason For Correctness: The correct answer is 'fossil fuels' because the text explains that people are using green technologies to rely less on these types of energy. In the summary, 'reducing their consumption of' matches the phrase 'reduce dependence on' in the text. |
| Q29 | alternative energy | The ideal alternative energy source would be sustainable (the supply will not be exhausted), clean (no emissions), and reliable | Excerpt/Passage Explanation: The passage explains that a perfect source of alternative energy must be long-lasting, clean, and dependable for meeting energy needs. Answer Explanation: The answer means power coming from natural, renewable sources—like the sun, wind, or heat from the ground—rather than traditional fossil fuels like coal or oil. Reason For Correctness: The correct answer is 'alternative energy' because the text mentions that people are looking for new options to meet their power demands without depending on fossil fuels. It highlights that the ideal 'alternative energy' source is one that will not run out, produces no pollution, and is reliable. |
| Q30 | sustainable | The ideal alternative energy source would be sustainable (the supply will not be exhausted), clean (no emissions), and reliable | Excerpt/Passage Explanation: The passage explains that the best new energy source would be sustainable, clean without pollution, and reliable. Answer Explanation: The answer means that the source of energy will not run out and can continue to be used in the future. Reason For Correctness: The correct answer is "sustainable" because the passage states that the best energy source has three main features: it is sustainable, clean (it produces no emissions or pollution), and reliable (it can be depended on). The sentence in the summary lists these same features, matching "sustainable" to the missing word. |
| Q31 | — | — | |
| Q32 | — | — | |
| Q33 | B / C / E | wells as deep as a mile or more can be drilled into underground reservoirs to tap steam and hot water that are used to run turbines and create energy. Power companies can then transmit this energy over power lines Geothermal power on a smaller scale can be used for heating and cooling houses or commercial buildings While geothermal heat pumps are an emissions-free and reliable source of energy, the biggest disadvantage is that such systems are expensive to install |
Excerpt/Passage Explanation: The passage shows that geothermal power is used by power companies to produce electricity (Choice B), can be used for both heating and cooling buildings (Choice E), and costs a lot of money to set up or install (Choice C). Answer Explanation: The answer choices B, C, and E state that geothermal energy is used by power companies to make energy, costs a lot of money to set up, and is used to make buildings both warm and cool. Reason For Correctness: The correct answer consists of choices B, C, and E because the passage mentions all three facts about geothermal power: 1. Choice B (run power plants): The text explains that wells are drilled to get steam and hot water to run turbines, and power companies send this electricity over power lines. 2. Choice C (costs a good deal of money to set up): The text states that the main problem with geothermal heat pump systems is that they are "expensive to install." 3. Choice E (used for cooling as well as heating): The text explicitly says geothermal power can be used for "heating and cooling houses or commercial buildings." |
| Q34 | — | — | |
| Q35 | — | — | |
| Q36 | A / C / D | The benefits of solar power vary according to how much exposure a given building has to the sun. However, one does not need to live in the desert to take advantage of solar power Some enterprising home-owners reduce the initial costs by purchasing inexpensive kits and setting up the system on their own |
Excerpt/Passage Explanation: The passage shows that solar energy changes based on how much sun a building gets, and it can still be used in places that are not hot deserts. It also shows that house owners can buy cheap kits and install the panels by themselves. Answer Explanation: The answer choices A, C, and D mean that solar power can be used in places without strong sun, owners can install it themselves instead of hiring an expert, and the amount of power made changes depending on how much sun hits the building. Reason For Correctness: The correct answer is made up of A, C, and D because all three facts are mentioned in the text. For choice A, the text states that people do not need to live in a desert to use solar power. For choice C, the text mentions that some owners set up the system on their own to save money instead of paying a professional. For choice D, the text explains that the benefits of solar power change depending on how much sun exposure a building gets. Choices B and E are not mentioned in the text. |
| Q37 | — | — | |
| Q38 | — | — | |
| Q39 | — | — | |
| Q40 | B / D / F / G | Like solar and geothermal energy, wind is a renewable resource that produces no emissions Small wind energy systems can be used by homes, farms, or communities If the turbine cannot deliver the needed energy, the power company then makes up the difference. However, in order to take advantage of wind energy, a turbine must be in an area with average wind speed of at least 10 miles an hour, and such systems can be very expensive |
Excerpt/Passage Explanation: The passage explains that wind energy creates no pollution, can be used by individual homes, works together with a power company's electricity when necessary, and needs to be set up in a place that gets a minimum speed of wind. Answer Explanation: The answer lists four true facts about wind energy given in the text: B (used by home-owners and power companies), D (must be placed where there is a certain amount of wind), F (can be used together with electricity from a power company), and G (is as clean as geothermal and solar energy). Reason For Correctness: The correct answer includes options B, D, F, and G because all four facts are directly stated in the text. Option B is correct because the passage explains that wind systems can be used by individual homes and that power companies send wind electricity through the utility grid. Option D is correct because the text states that a turbine needs to be in an area with an average wind speed of at least 10 miles per hour. Option F is correct because the text mentions that if a turbine does not make enough energy, the power company supplies the rest. Option G is correct because the text says wind energy creates no emissions, making it just as clean as solar and geothermal power. |