Energy resources
We use energy resources for transport, electricity and heating. Exam questions ask you to compare them: whether they will run out, whether they can supply power on demand, and what they do to the environment.
Part 1 of 3: Learn it
In short
- Renewable resources are replenished as they are used; non-renewable ones will run out.
- Fossil fuels and nuclear are reliable but have environmental costs.
- Wind and solar depend on the weather, so they need back-up from other sources.
Where this is in your specification
Spec points: AQA 4.1.3 (Combined Trilogy 6.1.3), Edexcel Topic 3, OCR P8.2
| Board | Topic: Energy stores, transfers and efficiency |
|---|---|
| AQA 8463 | 4.1 (8463); 6.1 (8464) |
| Edexcel 1PH0 | Topics 3 and 8 (specific heat capacity: Topic 14) |
| OCR J249 | P7 and P8.2; P5 and P6.2 (specific heat capacity: P1.2) |
| Eduqas C420 | 1.1 to 1.3 |
| Cambridge IGCSE 0625 | 1.7, 2.3 |
| National 5 C857 75 | Dynamics: energy; Properties of matter: specific heat capacity |
Renewable and non-renewable
| Resource | Renewable? | Reliable? | Main drawback |
|---|---|---|---|
| Coal, oil, gas | no | yes, on demand | release carbon dioxide; coal and oil also release sulfur dioxide |
| Nuclear | no | yes | radioactive waste; slow to start and expensive to close down |
| Wind | yes | no, needs wind | visual impact and noise |
| Solar | yes | no, only in daylight | large areas of panels for a small output |
| Hydroelectric | yes | yes | dams flood valleys and habitats |
| Tides | yes | yes, predictable | few suitable sites; affects estuary habitats |
| Waves | yes | no | small output; can affect shipping and marine life |
| Geothermal | yes | yes | only in a few volcanic areas |
| Biofuel | yes | yes | land used for fuel crops instead of food |
Reliability and demand
Demand for electricity rises and falls through the day. Gas power stations can be started quickly, so they are used to meet sudden rises or to cover times when there is little wind or sun. Nuclear stations take a long time to start up, so they provide a steady base supply.
Environmental effects
- Burning fossil fuels releases carbon dioxide, a greenhouse gas that contributes to climate change.
- Sulfur dioxide from coal and oil causes acid rain.
- Biofuels are described as carbon neutral when the plants absorbed the same carbon dioxide as they release when burned.
Trends
The UK has cut the share of electricity made from coal and increased the share from wind, solar and biomass. Barriers to faster change include cost, public opinion about wind farms and nuclear stations, and the need for back-up when renewables cannot supply enough.
Name two renewable resources that do not depend on the weather.
Show the answer
Any two of: tides, geothermal, hydroelectric, biofuel.
Part 2 of 3: See it worked
Worked examples
Example 1
A country generates 300 TWh of electricity in a year, and 135 TWh of it comes from renewable resources. What percentage is renewable?
- 135 ÷ 300 = 0.45
- 0.45 × 100 = 45
Answer: 45%.
Example 2
Explain why a gas power station is kept available in a region that relies on wind turbines.
- Wind turbines only generate when the wind blows at a suitable speed
- Demand still has to be met on calm days and at peak times
- A gas power station can be started up quickly when it is needed
Answer: It provides a reliable supply that can be switched on quickly when the turbines cannot meet demand.
Common mistakes
- Calling nuclear power renewable. Uranium is a finite resource.
- Saying renewable resources have no environmental impact at all.
- Mixing up greenhouse gases (carbon dioxide, climate change) with sulfur dioxide (acid rain).
- Assuming every renewable resource is unreliable. Hydroelectric, tidal and geothermal power can all be counted on.
Why is nuclear power described as non-renewable?
Show the answer
Its fuel, uranium, is mined and will eventually run out.
Part 3 of 3: Test yourself
Check yourself
Answer each one in your head or on paper first, then open it to check.
Name two renewable resources that do not depend on the weather.
Any two of: tides, geothermal, hydroelectric, biofuel.
Why is nuclear power described as non-renewable?
Its fuel, uranium, is mined and will eventually run out.
Give one environmental problem caused by burning coal.
It releases carbon dioxide, which adds to climate change (or sulfur dioxide, which causes acid rain).
Jobs that use this
- Renewable energy engineer (se abre en otra pestaña)
- Civil engineer (se abre en otra pestaña)
- Chemical engineer (se abre en otra pestaña)
Each link opens the job profile on the National Careers Service (England). In the rest of the UK: My World of Work (Scotland), Careers Wales, nidirect careers (Northern Ireland).
Estos apuntes están en inglés porque siguen los programas de examen del Reino Unido.
Full lessons and marked practice for this course are coming soon to Brainlag Learn. See courses