Key Idea: Most marks in topic 7.2 come from why countries choose their energy mix and how sustainable each source is. At HL, also learn energy security, fossil fuel dependence, nuclear power and batteries.
1. Energy choices (most marks)
- Choices depend on resources, cost, technology, politics, climate and public views.
- Norway gets about 89% of its electricity from hydropower; Poland about 54% from its own coal.
- France went nuclear after the 1973 oil crisis (68% in 2024); Germany closed its last reactors in 2023.
2. How sustainable each source is
- Fossil fuels are finite and emit carbon dioxide; oil spills, such as Deepwater Horizon (2010).
- Nuclear is low-carbon but leaves waste, with rare severe accidents: Fukushima (2011).
- Renewables are low-carbon but some are intermittent; dams flood land: Three Gorges moved 1.3 million people.
3. Demand and HL ideas
- World energy use in 2024 was about 4 times that of 1965 and set a new record.
- Demand grows with population and with use per person; about 81% still comes from fossil fuels.
- At HL: energy security, dependence on fossil fuels, nuclear power and large-scale batteries.
How it is examined:
| Question | How to score |
|---|---|
| [1] to [2] Describe an energy trend from data | Direction, years and values, with units. |
| [2] Calculate a percentage change | (new - old) / old x 100, with working and units. |
| [4] Explain why a country chose its energy mix | Name the country, link each factor to the choice. |
| [4] to [7] Evaluate an energy source | Strengths and limits for environment, people and cost, then a judgement. |
| [9] Discuss how a country could meet rising demand sustainably | Several sources and efficiency, named examples, a judgement. |
| [4] to [7] Explain how a country improved its energy security | Diverse supply, storage, less import, with a named case. |
Key terms, one line each:
| Term | In one line |
|---|---|
| Renewable energy | energy from sources that are naturally replaced, such as wind and sunlight |
| Non-renewable energy | energy from finite stocks, such as coal, oil, gas and uranium |
| Energy mix | the share of each source in a country's energy or electricity |
| Intermittent | not available all the time, such as solar at night |
| Energy efficiency | getting the same result while using less energy |
| Energy security | access to affordable, reliable energy for a country |
| Grid-scale battery | a large battery that stores spare electricity for the grid |
Last-minute check: answer, then tap to see.
How much of the EU's imported gas came from Russia in 2021? About 45%; by 2024 about 19%.
How did Lithuania cut Russian gas? A floating LNG terminal (2014); it stopped Russian gas imports in 2022.
What did the Hornsdale battery show? Big batteries can steady a grid with lots of wind power.
Is nuclear power renewable? No: uranium is finite, but it is low-carbon.
In 2022 gas supplies from Russia to Europe were cut and gas prices hit a record. Explain how a country can improve its energy security.
Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.
Exam tips
- For an energy choice, name the country and link each factor to its choice.
- Use dated figures: France 68% nuclear, Norway 89% hydropower.
- For a percentage change, show the working and give the unit.
- For energy security, use Europe in 2022 as the example.