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100
What is solar energy and what is it used for?
Solar energy is energy from sunlight and it is a renewable resource. Solar cells use sunlight to make electricity.
100
What is sunlight used for?
Sunlight is used to heat water for homes and swimming pools. It can also heat the air in buildings, such as greenhouses.
100
What are the advantages of solar energy?
Sunlight will not run out for billions of years. Solar energy does not cause any pollution.
100
What kind of resource is moving water?
Moving water is a renewable resource that is still used today.
100
What is a hydroelectric power plant?
Power plants that make electricity with the energy of flowing water are called hydroelectric power plants.
200
What are the disadvantages of wind energy?
The wind does not blow all the time. Birds sometimes are killed by flying into the towers or blades. Also, some people think that windmills are noisy and ugly.
200
Where are hydroelectric power plants built?
Usually built in dams.
200
What is geothermal energy?
Energy from the high temperatures inside the Earth is called geothermal energy.
200
Holland is famous for its very old windmills. Why were the turning blades connected to machines?
These windmills were used to grind grain and to pump water away from the land.
200
What are the advantages of nuclear power plants?
A nuclear power plant needs much less fuel than a power plant that uses coal or oil. Also, nuclear power plants do not give off smoke.
300
What are the disadvantages of geothermal energy?
These power plants can be built only a few places in the world where very hot rocks are close to Earth's surface. Some pollutants may be found in the steam of these plants.
300
What are the disadvantages of nuclear power plants?
The cost of building a nuclear plan is more than that of other power plants. Dangerous wastes present another problem. Since there is only so much uranium on Earth, nuclear energy is a nonrenewable energy source.
300
How is geothermal energy used?
In one way, water is pumped down deep holes into hot rock. As the water flows through cracks in hot rocks, the water gets hot and may turn into steam. The hot water or steam rushes back to the surface and is used to make electricity.
300
What are the disadvantages of solar energy?
It is not available at night or on cloudy days. Also, systems to make electricity from solar energy are expensive to make and maintain. Factories that make solar cells also produce very dangerous wastes.
300
What are the advantages of wind energy?
Windmills do not cause air pollution
400
What are the advantages of hydroelectric power plants?
They do not need fuel to make electricity. There is no pollution. No waste left behind.
400
What does a wind turbine do?
Wind turbines use the energy of the wind to spin a generator to make electricity. These wind turbines can spin faster in light winds than old windmills did. The electric energy they produce can be used in many ways, not just for pumping water or grinding grain.
400
What are the good and bad effects of building dams to run hydroelectric power plants?
Hydroelectric power plants do not pollute, and there is no waste. Dams flood habitats and may prevent fish from swimming up and down rivers.
400
What are the disadvantages of hydroelectric power plants?
They can only be built where there is moving water. The area also must have a place where a lake can form behind a dam. These lakes flood habitats of plants and animals. Dams can also stop fish from swimming up and down the rivers.
400
What are the advantages of geothermal energy?
Can make electricity all day and all night, all year long.
500
What is uranium and what is it used for?
Uranium is a rare metal. Under certain conditions, it gets very hot. Nuclear power plants use hot uranium instead of fossil fuel to make steam in order to produce electricity.
500
What is biomass? How is biomass used?
Biomass is material that was recently alive. Biomass can be animal waste, wood, grasses, or food wastes. Biomass can be used in other ways, besides being burned into power plants. Some biomass is turned into fuels that can run cars and trucks. Chemicals are added to biomass, and then the biomass is turned into a liquid fuel. High temperatures can turn biomass into a gas similar to natural gas.
500
Why were factories built along rivers for centuries?
To use the energy of the flowing water.
500
What is a disadvantage of biomass?
Causes air pollution.
500
Will we ever run out of biomass?
Biomass is a resource that we will never run out of. We will always have garbage.