Fuels for electricity
How do fossil fuels produce electricity?
Power stations that are fuelled by coal and oil, operate on the same basic principle. The fuel is burned and the heat produced is used to boil water. This creates high-pressure, super heated steam, which is then used to turn a turbine. The turbine turns a generator and so it generates electricity.
- No CO2
- Does not work in high low wind
- Can generate 24hours a day
- Set up cost and enviromental impact
- no CO2
- only get energy 10hours a day
- No CO2
- Not efficient
Geothermal energy involves harnessing the thermalenergy stored within the earth. This thermal energy comes from the decay of radio active elements, such as uranuim, in rocks under the ground.The heat released by this radio active decay warms the surrounding rockand nearby water.
In some areas, the geothermal rocks are deep under ground where these is no water. Where this occurs, wells can be drilled down to the rocks and cold water is pumped down. The water is heated by the rocks and returns to the surface as steam.
- No CO2
- requires access to hot rocks
Energy and the Enviroment
Carbon dioxide- green house gas is the main waste product of burning fossil fuels
Sulphur dioxide and nitric oxide- these gaseous pollutants contribut to the formation of smog and acid rain
Ash- this waste solid is disposed of in landful sites
Fog + smoke= smog
The national grid
- The national grid transfers the electricity form a powerstation to our home and controls electricity flow
- powerstations produce electricity at 25000v
- step up transformer then increase this to 400000v
What difference would it make if we didnt step up the grid voltage?
- We would lose energy and they wouldnt be enough for the houses
Powerstations are connected to the nation grid using step-up transformers. This type of transformer makes voltage bigger.Homes are connected to the national grid using step-down transformers. This type of transformer makes voltage bigger
Coal,oil and nuclear
- cheap fuel cost
- good for 'basic demand'
- short start up time for gas and oil
- nuclear produce little pollution
- Cost a lot of money to decommision a nuclear plant
- fuel will run out
- pollution-CO2 leads to global warming and SO2 leads to acid rain
Wind, tidal, hydroelectric and solar
- zero fuel cost
- dont produce pollution
- hydroelectric is good for a 'sudden' demand
- solar is good for remote locations
- unreliable(except hydro electic)
- expensive to build
- tidal barriages destroy habitats of wading birds and hydro electric schemes involved flooding farmland