Electricity Flashcards
What are the three fossil fuels?
The fossil fuels are coal, oil and natural gas. They release heat energy when they are burned. They are non-renewable.
Give some disadvantages of fossil fuels.
Fossil fuels are non-renewable energy resources: their supply is limited and they will eventually run out. Fossil fuels do not renew themselves, while fuels such as wood can be renewed endlessly. Coal and oil release sulphur dioxide gas when they burn, which causes breathing problems for living creatures and contributes to acid rain. Fossil fuels release carbon dioxide when they burn, which adds to the greenhouse effect and increases global warming. Of the three fossil fuels, for a given amount of energy released, coal produces the most carbon dioxide and natural gas produces the least.
What are the two nuclear fuels?
Uranium and Plutonium, these are radioactive metals.
What are the advantages of nuclear fuels?
Nuclear fuels do not produce carbon dioxide or sulfur dioxide.
What are the disadvantages of nuclear fuels?
Nuclear fuels are non-renewable energy resources. If there is an accident, large amounts of radioactive material could be released into the environment. In addition, nuclear waste remains radioactive and is hazardous to health for thousands of years. It must be stored safely.
What is wind energy?
The wind is produced as a result of giant convection currents in the Earth’s atmosphere, which are driven by heat energy from the sun. This means that the kinetic energy in wind is a renewable energy resource: as long as the sun exists, the wind will too.
How do wind turbines work?
Wind turbines use the wind to drive turbines directly. They have huge blades mounted on a tall tower. The blades are connected to a ‘nacelle’, or housing, which contains gears linked to a generator. As the wind blows, it transfers some of its kinetic energy to the blades, which turn and drive the generator. Several wind turbines may be grouped together in windy locations to form wind farms.
What are the advantages of wind energy?
Wind is a renewable energy resource and there are no fuel costs. No harmful polluting gases are produced.
What are the disadvantages of wind energy?
Wind farms are noisy and may spoil the view for people living near them. The amount of electricity generated depends on the strength of the wind. If there is no wind, there is no electricity.
Describe wave energy.
The water in the sea rises and falls because of waves on the surface. Wave machines use the kinetic energy in this movement to drive electricity generators.
Describe tide energy.
Huge amounts of water move in and out of river mouths each day because of the tides. A tidal barrage is a barrier built over a river estuary to make use of the kinetic energy in the moving water. The barrage contains electricity generators, which are driven by the water rushing through tubes in the barrage.
Describe hydroelectric energy.
Like tidal barrages, hydroelectric power (HEP) stations use the kinetic energy in moving water. But the water comes from behind a dam built across a river valley. The water high up behind the dam contains gravitational potential energy. This is transferred to kinetic energy as the water rushes down through tubes inside the dam. The moving water drives electrical generators, which may be built inside the dam.
What are the advantages of water power?
Water power in its various forms is a renewable energy resource and there are no fuel costs. No harmful polluting gases are produced. Tidal barrages and hydroelectric power stations are very reliable and can be easily switched on.
What are the disadvantages of water power?
It has been difficult to scale up the designs for wave machines to produce large amounts of electricity. Tidal barrages destroy the habitat of estuary species, including wading birds. Hydroelectricity dams flood farmland and push people from their homes. The rotting vegetation underwater releases methane, which is a greenhouse gas.
What are the advantages of geothermal power?
Geothermal energy is a renewable energy resource and there are no fuel costs. No harmful polluting gases are produced.
