National & global energy resources

Energy resources are either renewable or non-renewable.

What is meant by a ‘renewable energy resource’?

Tick () one box.

The energy resource can be burnt.

The energy resource can be destroyed.

The energy resource can be replenished.

Figure 1 shows the percentage of electricity generated by different energy resources on one day in 2024.

Figure 1

Calculate the percentage of electricity generated using wind.

Use Figure 1.

A wind turbine generated 200 000 W of electrical power in a time of 300 seconds.

Calculate the energy transferred by the wind turbine.

Use the equation:

energy transferred = power × time

Why do wind turbines have a small environmental impact when generating electricity?

Tick () one box.

Wind turbines do not burn fuel to produce electricity.

Wind turbines have no moving parts.

Wind turbines occupy large areas of land.

Which two of the following emit carbon dioxide when used to generate electricity?

Tick () two boxes.

Biofuel

Gas

Hydroelectric

Nuclear

Solar

Give one environmental problem caused by carbon dioxide emissions.

Energy resources are renewable or non-renewable.

Which two of the following energy resources are renewable?

Tick (✓) two boxes.

Biofuel

Coal

Nuclear

Oil

Wind

Figure 5 shows wind turbines in the countryside.

What are two effects on the environment of using wind turbines to generate electricity?

Tick (✓) two boxes.

Some birds are killed by wind turbines.

There is no fuel cost when using wind turbines.

Wind is an unreliable energy resource.

Wind turbines generate lots of electricity in windy conditions.

Wind turbines produce low frequency noise.

Figure 6 shows a wind turbine.

The useful power output of the generator in the wind turbine is 144 000 W.

The efficiency of the wind turbine is 0.30

Calculate the total power input to the wind turbine.

Use the equation:

Use the Physics Equations Sheet to answer Questions 05.4 and 05.5.

Which equation links current, potential difference and power?

Tick (✓) one box.

power = potential difference × current

The power output of the generator in the wind turbine is 144 000 W.

The potential difference across the generator is 960 V.

Calculate the current in the generator.

Figure 7 shows how the National Grid links the wind turbine to consumers.

The step-up transformer increases the potential difference and decreases the current.

What effect does decreasing the current have on the energy loss from the power cables?

Tick (✓) one box.

The energy loss decreases.

The energy loss is not affected.

The energy loss increases.

What is the function of the step-down transformer in Figure 7 ?

Tick (✓) one box.

To decrease the current.

To decrease the potential difference.

To decrease the power input.

Energy resources are renewable or non-renewable.

Which two energy resources are non-renewable?

Tick (✓) two boxes.

Coal

Nuclear

Tidal

Wave

Wind

Why has the electricity demand per person in the UK decreased over the past five years?

Tick (✓) one box.

Energy-efficient appliances are being bought.

Power stations are generating more electricity.

The number of electric cars in the UK has increased.

Which energy resource releases carbon dioxide when burnt?

Tick (✓) one box.

Crude oil

Hydroelectric

Solar

Uranium

Some heating appliances burn natural gas.

Burning natural gas produces a third of the UK’s carbon dioxide emissions.

Scientists are investigating whether these heating appliances can burn a mixture of hydrogen gas and natural gas.

In a 2.0 kg mixture of hydrogen gas and natural gas there is 0.4 kg of hydrogen gas.

Calculate the percentage by mass of hydrogen gas in this mixture.

Burning a mixture of hydrogen gas and natural gas releases less carbon dioxide compared with burning only natural gas.

Explain one advantage of releasing less carbon dioxide into the atmosphere.

Heating homes and businesses using natural gas produces a third of the UK’s carbon dioxide emissions.

Give one energy resource that produces carbon dioxide when burnt.

Do not refer to natural gas.

Hydrogen can be burned to power cars.

Hydrogen can be extracted from seawater.

Burning 1 kg of hydrogen releases 142 MJ of energy.

Burning 1 kg of petrol releases 45 MJ of energy.

Give two advantages of using hydrogen to power cars compared with using petrol.

Scientists are investigating whether appliances that usually only burn natural gas can burn a mixture of hydrogen gas and natural gas.

Give three environmental benefits of burning a mixture of hydrogen gas and natural gas compared to just burning natural gas.

All gas appliances in the UK bought since 1996 can burn a mixture of 23% hydrogen gas and 77% natural gas.

Explain a possible problem of changing the UK gas supply to this mixture of hydrogen gas and natural gas.

An energy input of 1.3 × 10¹⁸ J is supplied each year by power stations to the National Grid.

Not all of this energy is supplied to consumers. Some of the energy is wasted in the distribution process.

Write the equation which links efficiency, total input energy transfer and useful output energy transfer.

The energy supplied each year to consumers is 1.2 × 10¹⁸ J

Calculate the efficiency of the distribution process.

How is electrical power transmitted across the National Grid to make the process as efficient as possible?

Tick one box.

Write the equation which links energy transferred, power and time.

A wind turbine supplies a power output of 8000 kW for 1200 seconds.

Calculate the energy transferred by the wind turbine in kJ

Describe the environmental advantages and disadvantages of using wind turbines to generate electricity in the UK.