Post on 19-May-2015
Producing ElectricityProducing ElectricityBy the end of the lesson you should be
able to:• Give examples of non-renewable
energy sources and describe the advantages and disadvantages of using them
• Describe how electricity is generated at a power station
• Know how the National Grid connects power stations to homes
Key WordsKey WordsKey WordsKey Words
Turbine
Generator
Transformer
National grid
Power stations
Cooling tower
Turbine
Generator
Transformer
Boiler
What are the energy changes that occur?
What does each part do?
The boiler is where the fuel is burnt to boil water
The steam from the boiler is used to turn a turbine
The turbine is connected to the generator, which acts like a dynamo – it generates electricity out of movement
The steam is cooled down and turned back into water in the cooling tower
Nuclear power stationsThese work in a similar way to normal power stations:
The main difference is that the nuclear fuel is NOT burnt – it is used to boil water in a “heat
exchanger”
Advantages of non-renewable fuels
Coal, oil and gas
Nuclear
Relatively cheap
Reliable
Flexible in meeting demand
Relatively easy to find
Cheap fuel costs
Don’t produce as much pollution
The problems…Power stations using coal, oil, gas or nuclear fuels can certainly whack out the energy, BUT…
Problem 1 – Fossil fuels and nuclear sources will RUN OUT
Problem 2 – Burning fossil fuels in oxygen will pollute the atmosphere
Problem 3 - Nuclear plants run the risk of contamination and the cost of shutting them down (“decommissioning”) is very high
So what’s the solution?
Other ways of generating electricity…
Can we drive the turbine DIRECTLY?
Other ways of generating electricity…
Wind
TidalWave
Hydro-electric
What are the disadvantages of these renewable forms of energy?
Source Disadvantages
Wind
Wave
Tidal
Hydroelectric
Source Disadvantages
Wind Depends on weather, visual pollution, difficult to “store”
Wave Harms wildlife, depends on size of waves, depends on weather
Tidal Depends on size of tides, harms wildlife, visual pollution
Hydroelectric Habitats can be destroyed, only good as a “short term” supply
Also, these sources all have high setting up costs
Summary
Renewable sources of energy are cheaper, cleaner and will not run out. However, they are incapable of providing all the energy we need, so we will have to
go on burning fossil fuels for now.