Determine and Analyze Central Ideas Practice Test
•10 QuestionsRead the passage and answer the question.
When people talk about renewable energy, they often focus on the type of technology—solar panels, wind turbines, or hydropower. The passage explains, however, that the bigger question is what these sources replace. Electricity made by burning coal or natural gas releases carbon dioxide, a greenhouse gas that traps heat in Earth’s atmosphere. In contrast, solar and wind generate electricity without releasing carbon dioxide during operation, so switching to them can lower overall emissions.
The passage also develops a second idea: renewable energy can be expensive at first, but it may save money over time. Building wind farms or installing rooftop solar requires upfront spending for equipment and construction. Yet once installed, the “fuel” for wind and sunlight is free, and maintenance costs can be predictable. Over many years, that can make the total cost competitive with fossil fuels, especially when fuel prices rise.
Finally, the passage notes that renewables require planning. Because wind and sunlight vary, power companies may add batteries, connect to larger regional grids, or keep some flexible power plants available. These steps help ensure electricity is reliable while emissions decrease.
Question: How is the idea that renewable energy can save money over time developed across the passage?
Read the passage and answer the question.
When people talk about renewable energy, they often focus on the type of technology—solar panels, wind turbines, or hydropower. The passage explains, however, that the bigger question is what these sources replace. Electricity made by burning coal or natural gas releases carbon dioxide, a greenhouse gas that traps heat in Earth’s atmosphere. In contrast, solar and wind generate electricity without releasing carbon dioxide during operation, so switching to them can lower overall emissions.
The passage also develops a second idea: renewable energy can be expensive at first, but it may save money over time. Building wind farms or installing rooftop solar requires upfront spending for equipment and construction. Yet once installed, the “fuel” for wind and sunlight is free, and maintenance costs can be predictable. Over many years, that can make the total cost competitive with fossil fuels, especially when fuel prices rise.
Finally, the passage notes that renewables require planning. Because wind and sunlight vary, power companies may add batteries, connect to larger regional grids, or keep some flexible power plants available. These steps help ensure electricity is reliable while emissions decrease.
Question: How is the idea that renewable energy can save money over time developed across the passage?