Generating Electricity Flashcards
What are fossil fuels?
Fossil fuels are coal, oil and natural gas. They were formed from the remained of living organisms millions of years ago and they release heat energy when burned. They are non renewable.
What is used as a nuclear power station fuel?
Uranium or plutonium.
What are biofuels?
Biofuels are renewable sources of energy which can generate electricity.
Most power stations burn fuels to produce energy to heat water. However in a nuclear power station uranium isn’t burned. So where does the energy come from?
It comes from the process of nuclear fission.
How is lots of the energy released in nuclear power stations?
There are lots of uranium nuclei, so lots of fission reactions take place, releasing lots of energy. This energy is used to heat water, turning it into steam.
What do nuclear power stations release if they don’t release any greenhouse gases what do they release instead?
Nuclear power stations produce radioactive waste that must be safely stored for a long period of time.
Give an advantage and disadvantage of coal
- They produce energy efficiently and fast
- They will run out eventually and they give off pollutants like CO2 and sulphur.
Give all the renewable energies
Wind Water- hydroelectric Tidal Wave Solar
What is a wind turbine?
An electricity generator on top of a tall tower.
What can we use energy from the wind and water for?
To drive turbines directly
What happens in a wind turbine?
The wind passing over the blades makes them rotate and drives a generator at the top of a narrow tower.
In water how can electricity be produced?
From falling water
Waves
Tides
How does hydroelectric power work?
At a hydroelectric power station water is collected in a reservoir. This water is allowed to flow downhill and turn turbines at the bottom of the hill.
What form of energy is stored in the water in the top of the reservoir of a pumped storage scheme?
Gravitational potential energy
What can we do with wave power?
We can use the movement of the waves on the sea to generate electricity. The movement drives a floating turbine that turns a generator. Then the electricity is delivered to the grid system on shore by a cable
How can we use tidal power?
The level of sea around the coastline rises and falls twice each day. These changes in the sea levels are called tides. If a barrage is built across a river estuary, the water at each high tide can be trapped behind it. When the water is released to fall down to the lower sea level, it drives turbines.
Why is wave power likely to be less reliable than tidal power?
There are always two tides daily but on a calm day there may not be any waves.
Where does solar energy travel?
It travels from the sun and through space into the earth as electromagnetic radiation.
What can solar cells do?
They transfer solar energy directly into electricity.
What do solar heating panels do?
They use the suns energy to heat water directly
Why are large numbers of solar cells often joined together to make a solar panel?
Each solar cell only produces a small amount of electricity.
Where does geothermal energy come from?
Inside the earth
How can electricity be produced by geothermal energy?
Geothermal energy is produced inside the earth from heats surrounding rocks. Very deep holes are drilled and cold water is pumped down to the hot rocks. There it is heated and comes back to the surface as steam which is used to drive turbines to turn generators.
Why are only a few places in the world able to have geothermal energy?
In many places the hot rocks may be too far below the surface to be used.
