A
Solar energy systems & power plants do not produce air pollution, water pollution, or greenhouse gases. Using solar energy can have a positive, indirect effect on the environment, when solar energy replaces or reduces the use of other energy sources that have larger effects on the environment.
However, some poisonous materials and chemicals are used to make the photovoltaic ( 光电池的) cells that convert sunlight into electricity. Some solar thermal (保热的) systems use potentially hazardous liquids to transfer heat. Leaks of these materials could be harmful to the environment. U. S. environmental laws regulate the use and settlement of these types of materials.
As with any type of power plant, large solar power plants can affect the environment near their locations. The placement of the power plant may have long-term effects on the habitats of native plants and animals. Some solar power plants may require water for cleaning solar collectors and concentrators or for cooling turbine generators. Using large volumes of ground water or surface water in some dry locations may affect the ecosystems that depend on these water resources. In addition, the beam of concentrated sunlight a solar power tower creates can kill birds and insects that fly into the beam.
The amount of solar energy that the earth receives each day is many times greater than the total amount of all energy that people consume each day. However, on the surface of the earth, solar energy is a variable and irregular energy source. The amount of sunlight and the intensity of sunlight varies by time of day and location. Weather and climate conditions affect the availability of sunlight daily and on a seasonal basis. The type and size of a solar energy collection and conversion system determines how much of the available solar energy we can convert into useful energy.
21.Which of the following best explains "hazardous" underlined in paragraph 2?
A. Inexpensive B. dangerous C. Ineffective D. abnormal
22.What influence can large solar power plants have on the locations?
A. Polluting the ground water.
B. Protecting the habitats of plants and animals.
C. Damaging the local natural balance.
D. Attracting birds and insects to the area.
23.What does the last paragraph mainly tell us?
A. Different areas receive different amount of solar energy.
B. How to convert solar energy into useful energy.
C. The relationship between solar energy collection and the sunlight.
D. Some factors that influence the amount of solar energy collection.
