Electricity is convenient as we can change it into many different energies.
We generate it using non-renewable and renewable sources.
There are advantages and disadvantages of both
Fossil Fuels
Coal, Oil and Natural gas
Formed from remains of living organisms millions of years ago. They are non-renewable
Fossil fuel is a store of chemical energy
When they are burned they are transferred as heat.
Which heats up water and becomes steam which rises
The heat is transferred into kinetic energy.
The steam drives turbines which turns a generator and the energy is transferred into electrical energy.
Advantages
Reliable, 3/4 of power stations are fueled by fossil fuel.
Disadvantage
Non-renewable- supply is limited and will run out.
Release of sulfur dioxide which causes acid rain
Carbon dioxide is released. They are a green house gas therefore contribute to global warming.
Coal releases the most pollution and natural gas releases the least for a given amount of energy released.
Carbon capture
We can store carbon dioxide in old oilfields or gas fields under the North Sea.
Nuclear fuels
Nuclear fuel are mainly uranium or plutonium which are radioactive metals.
They go through nuclear fissions which release a vast amount of heat energy.
The heat energy is used to boil water which turns to steam.
The steam is used to spin turbines which drives generators to produce electricity.
Advantages
They don't release carbon dioxide and sulfur dioxide. Reliable
Disadvantages
Non-renewable source, limited supply and will run out.
Radioactive waste which can be hazardous for thousands of years and needs to be stored safely.
There is a chance of an accident which can lead to large amounts of radioactive material to be released into the environment e.g. chernobyl disaster
Wind Energy
Convection currents in the Earth's Atmosphere driven by heat energy from the sun.
Kinetic energy in wind is renewable
Wind drives the blades of a wind turbines to spin, they have gears that link to a generator.
Wind Farms can be formed by several wind farms grouped together.
Advantage
renewable energy- unlimited supply
No harmful polluting gas produced
no fuel cost
Disadvantages
Not reliable- there are days without wind.
Noise and sight pollution
Expensive
Water
Wave
Wave machines use kinetic energy of waves as they rise and fall to drive electricity
Tides
Water move in and out of river mouths because of tides
A tidal barrage built over a river estuary uses the kinetic energy of the moving water.
They drive generators as they rush through tubes in the barrage.
Hydroelectric
Dams can be built to generate electricity across a river valley.
Area behind the dam is flooded and water is used to drive generators as they rush down tubes in the dam to the otherside.
The water contain gravitational potential energy which transfers to kinetic energy as they fall.
Advantages
Renewable energy
No fuel cost
No pollutant gas
Dams and tidal barrages are reliable.
Disadvantages
Expensive
Wave machines are difficult to scale up to produce large amounts of energy
Tidal barrages destroys habitats of organisms
Dams flood farmlands and people are forced to leave their homes.
Rotting vegetation under the water release methane which is a greenhouse gas.
Geothermal energy
Some rocks in the crust contain radioactive substances such as uranium.
The radioactive decay of these releases heat energy.
In volcanic areas, the rock may heat water so it rises naturally and drives turbines to generate electricity.
Sometimes we have to pump water down so they can be heated by the hot rocks so that steam can rise up as steam at a different location.
Advantages
Renewable source
Reliable
No fuel cost
No harmful pollutant gas
Disadvantages
Not all areas of the world are suitable for this type of method.
Solar Energy
Solar cells convert light into electrical energy.
These are different from solar panels.
Advantages
Renewable
No fuel cost
No harmful pollutant gas
Can provide electricity in remote locations
Disadvantages
Expensive and unreliable + inefficient
Do not work at night
Power Stations
Different power stations have different start up time
Start up time for power stations are as follows starting from the shortest
Gas
Oil
Coal
Nuclear
The bottom ones are used to provide base load electricity.
The shorter ones provide extra electricity at peak times.
It is expensive to dismantle old nuclear power stations.
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