National & Global Energy Resources (AQA GCSE Physics)

The UK is starting to use wind turbines to generate more of its electrical energy.

Some people think this is a good idea, other people do not.

Suggest reasons why people think that building more wind turbines is a good idea.

It is difficult to store electrical energy that is produced by any kind of power plant.

One solution is a pumped storage dam.

Figure 1 shows a diagram of a pumped storage system.

Figure 1

Read the following passage:

During times of low demand, water is pumped up into the upper reservoir. During times of high demand, sluice gates are opened and water flows down through the generator, producing electrical energy. Pumped storage stations are designed to meet sudden, high demand for electrical energy, such as when thousands of people put their kettle on at half time of a major football game at the same time.

A pumped storage station has a very short start-up time.

Why is it important for the pumped storage station to have a short start-up time?

Figure 2 shows some solar panels on the roof of a house.

Figure 2

The amount of solar energy hitting the solar panels in one day is equal to 700kWh. 

The amount of energy the solar panels generate is 175 kWh.

The kWh is a unit of energy.

A photovoltaic panel generates electrical energy.

Suggest why the government wanted people to use solar power rather than fossil fuels.

The UK government has also made money available to help to build houses that are well insulated.

Describe the features of the walls of a building that cools down very slowly.

A company wishes to build a science park at a coastal location in the UK.

To demonstrate its commitment to sustainability, the company wants to develop a renewable method of powering the buildings.

They are considering three options:

• biofuel
• geothermal power
• wind turbines

Evaluate the use of renewable resources to power the science park.

Representatives from the people who live near the site do not like this idea.

Suggest arguments for both the nuclear company and for the people who live close by.

The company also wishes to use renewable energy for the transport around the science park.

Due to the low amount of energy that batteries can store, battery powered cars need to be very efficient.

State the equation for efficiency.

A typical electric car battery can store 144 MJ of energy before it needs to be recharged.

Using the battery, the car can produce 50 MJ of useful energy before it needs to be recharged.

Calculate the efficiency of the car.

The electrical power demand of the UK is at least  at any given time.

An average gas-fired power station has a power output of .

Determine how many gas-fired power stations are needed to meet the demand of the UK.

The UK only has 32 active gas-fired power stations.

Calculate the shortfall.

Energy from the sun is released by the process of nuclear fusion.

Scientist are working hard to create the process of nuclear fusion on Earth. This is referred to as cold fusion.

Nuclear fusion is difficult to achieve on Earth. Sate two reasons why.

The specific heat capacity of deuterium is 5200 J/kg °C

Calculate the energy required to increase the temperature of 6.5 g of deuterium by 60 000 000 °C.

Give your answer in MJ.

Suggest why cold fusion is not yet considered an viable energy resource.

A tidal barrage (dam) produces electricity using tides. Figure 1 shows a simplifies diagram of a tidal barrage.

Figure 1

Water flows through the tunnel when the tide goes in or out. The moving water turns the turbine, which produces electricity.

The turbine has a cylindrical shape as the turbine spins in a circular path as shown in Figure 1.

The cylinder is 24 m long and has a radius of 5.0 m.

The tide is travelling at 6.0 m/s.

Figure 1

Calculate the kinetic energy of this cylinder of sea water.

Density of sea water = 1020 kg/m³

In America, it is estimated that tidal power would cost $150 per MWh produced, whereas coal only costs $60 per MWh produced.

Suggest why tidal power is more expensive than power from fossil fuels.

Some ocean environmental groups oppose the use of tidal power, stating that it can physically harm aquatic life, as well as impacting their ability to communicate. 

Suggest why these statements could be correct.

One possible short term solution to the global energy crisis is to extract shale gas. Shale gas is natural gas trapped in the rocks underground. This gas can be extracted by a process called fracking. In places where fracking has been done, there is some evidence that it can cause minor earthquakes. Because shale gas is natural gas (methane), it is a fossil fuel.

Another possible solution is to build more nuclear power stations. Nuclear power stations use fission to generate electricity.

Suggest why the old nuclear power plants are being closed down.

Explain the function of the control rods.

22% of the UK's power generation was produced by nuclear power in the year of 2022.

Nuclear reactors use the process of fission to generate electricity.

Complete the diagram to show how a chain reaction is produced.

Calculate the total power required to vaporise the water used over a period of 24 hours.

You can assume that the power plant is operating at full capacity during this time.

• The specific heat capacity of water is 4200 J/kg°C.
• The latent heat of vaporisation of water is 2 260 000 J/kg.

Give your answer in MW.

Control rods inside a nuclear reactor absorb neutrons and control the rate of the fission reaction.

Figure 2 shows the rate of a fission reaction with no control rods in the reactor.

 Figure 2

Explain what would happen if the reaction were to continue.

Discuss the advantages and disadvantages of nuclear power as an energy resource.