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.