Cambridge IGCSE Geography (0460): Theme 3.5 – Energy – Revision Notes

These notes condense the energy study guide, so read that first if a point here is unclear.

They cover Topic 3.5 Energy from the Cambridge IGCSE Geography (0460) syllabus for examination in 2025 and 2026, Version 2 (published November 2022). The topic is examined in Paper 1 Geographical Themes, and the syllabus lists energy among the things graphs in Paper 2 Geographical Skills may show. When you are ready, test yourself with the energy practice questions. For other topics, use the Cambridge IGCSE Geography hub and the IGCSE Geography checklist.

What the syllabus asks

• Describe the importance of non-renewable fossil fuels (coal, oil, natural gas), renewable supplies (geothermal, wind, HEP, wave and tidal, solar, biofuels), nuclear power and fuelwood – globally and in countries at different levels of development.
• Evaluate the benefits and disadvantages of nuclear power and renewable sources.
• Case study: energy supply in a country or area.

Key terms

Term	Meaning in one line
Non-renewable	A stock that runs out: coal, oil, gas, uranium
Renewable	A flow that is naturally replaced: sun, wind, water, Earth’s heat
Fossil fuel	Coal, oil or gas formed from ancient plant and animal remains
Fuelwood	Wood or charcoal burned for cooking and heating
Nuclear power	Electricity from the heat of splitting uranium atoms
HEP	Electricity from water flowing through turbines, usually below a dam
Geothermal	Heat from hot rocks underground, used for steam or direct heating
Biofuel	Fuel from plant or animal material, such as sugarcane ethanol
Energy mix	The share of energy from each source in one country
Intermittent	Not available all the time (solar at night, wind on calm days)
Energy security	A reliable, affordable supply not dependent on one source or supplier

Global picture in four numbers

• About 80% of world energy consumption came from fossil fuels (2022).
• Nuclear supplied about 4.3% of world primary energy (2020).
• Hydro, wind and solar together generated about 29% of world electricity in 2024 (hydro 14.4%, wind 8.1%, solar 6.9%).
• About 2.1 billion people cook with polluting fuels such as wood, dung, crop waste, kerosene or coal (WHO).

Sources at a glance

Source	Needs or suits	One benefit	One disadvantage	Real example
Coal	Large reserves; power stations	Cheap, reliable	Most carbon dioxide per unit of energy	Main electricity fuel worldwide (34.4% in 2024)
Oil	Transport and chemicals	Easy to store and move	Price shocks for importers	1973 oil crisis pushed France into nuclear
Natural gas	Pipelines or shipping	Less carbon dioxide than coal	Still a fossil fuel; supply can be cut	–
Fuelwood	Rural areas with no grid	Free to collect	Indoor smoke; deforestation	WHO: 2.9 million deaths linked to household air pollution (2021)
Nuclear	Money, skills, cooling water	Large, steady, low-carbon	Waste; accident risk; cost	France, about 72% of electricity (2018)
Geothermal	Plate boundaries, volcanic areas	Steady day and night	Few suitable places; gases	Hellisheiði, Iceland, 303 MW; Olkaria, Kenya
Wind	Strong, steady winds; coasts, uplands, offshore	No fuel cost	Intermittent; visual impact	–
HEP	High rainfall, steady flow, deep narrow valley	Large, controllable output	Floods land; displaces people	Three Gorges, China, about 22,500 MW
Wave	Exposed coasts	Strong resource	Mostly at trial stage	–
Tidal	Large tidal range, estuary	Predictable	Few sites; habitat change	La Rance, France, 240 MW, 1966
Solar	Sunny, low-latitude areas	Works off-grid on single homes	No output at night	–
Biofuel	Land for crops such as sugarcane	Replaces petrol	Competes with food crops	Brazil, ethanol programme from 1975

Must-know distinctions

• Renewable vs low-carbon. Nuclear is low-carbon but not renewable. Biofuels are renewable but release carbon dioxide when burned.
• Energy vs electricity. A country can make nearly all its electricity from renewables and still import oil for transport (Iceland).
• Intermittent vs controllable. Wind and solar depend on the weather; HEP, geothermal and nuclear can run steadily.
• Predictable vs reliable. Tides are predictable to the minute, but output still stops for a while at each slack water around high and low tide.
• Describe vs evaluate. Describe importance = what it supplies, where and for whom. Evaluate (the syllabus wording) = weigh benefits against disadvantages and reach a judgement; in the exam this often appears as “To what extent …?” or “How far do you agree …?”.

Levels of development in one table

	Low income	Middle income	High income
Energy per person	Low	Rising fast	High
Typical main sources	Fuelwood, some oil, HEP	Coal and oil, growing renewables	Oil, gas, nuclear, renewables
Main problem	No grid; smoke; deforestation	Coal pollution; demand growth	Cutting emissions

In 2018 the USA used 4.4 tonnes of oil equivalent per person and India 0.4, against a world average of 1.2.

Case study card: Iceland

• On the Mid-Atlantic Ridge (constructive boundary) -> geothermal heat; high rainfall and glaciers -> HEP.
• 2016: about 85% of primary energy from domestic renewables (geothermal about 65%, hydro 20%); most of the rest imported fossil fuel.
• 2025: electricity 70.5% hydro, 29.4% geothermal.
• About 90% of homes heated by geothermal energy.
• Hellisheiði geothermal plant: 303 MW; gases reinjected underground since 2014 to cut hydrogen sulphide.
• Kárahnjúkar HEP: 690 MW, 193 m dam, built to power Alcoa’s Fjarðaál aluminium smelter; protests over flooded highland.
• 2005: 72% of electricity used by power-intensive industry.
• Still imports oil for vehicles, ships and aircraft.

Mini essay plan

Question type: “To what extent is renewable energy a better choice than nuclear power for reducing a country’s use of fossil fuels?”

1. Define and frame. Both are low-carbon; only renewables are renewable. The answer depends on the country’s physical geography and wealth.
2. For renewables. No fuel cost; no radioactive waste; can be small and local (solar in villages). Example: Iceland’s hydro and geothermal.
3. Against renewables. Wind and solar are intermittent; HEP and tidal floods or alter land and estuaries. Example: Three Gorges displacement.
4. For nuclear. Large, steady supply. Example: France’s reactors after the 1973 oil crisis.
5. Against nuclear. Cost, waste and accident risk (Chernobyl 1986, Fukushima 2011); rarely possible in low-income countries.
6. Judgement. Renewables are the better choice where conditions suit them and for poorer countries; nuclear can provide steady base load in wealthy countries. Many countries use both.

Model evaluation paragraph

“Tidal power is predictable because tides follow a known daily pattern (knowledge). La Rance in Brittany has generated electricity since 1966 from a tidal range of about 8 metres, with a capacity of 240 MW (application). However, the barrage has caused silting of the estuary, and few coasts have a large enough tidal range, so tidal power can only ever supply a small share of most countries’ needs (analysis). It is a reliable low-carbon source in the right place, but not a national solution for most countries (evaluation).”

Use the same four steps for any source: what it is, a real place, a consequence, then a judgement that says where or for whom it works.

Data skills to rehearse

• Percentages. Share of a source = source ÷ total × 100. Check that the shares in a table add up to the total before you start.
• Percentage change. (new − old) ÷ old × 100. Say whether it is an increase or a decrease.
• Capacity vs output. Capacity is in MW (power). Output over time is in MWh, GWh or TWh (energy). Output = capacity × hours × the share of time it runs.
• Describing a graph. Give the overall trend, the highest and lowest values, any anomaly, and quote figures with units.
• Divided bars and pie graphs. Compare the biggest segment in each country first, then the most surprising difference.

Quick self-test

1. Name the three fossil fuels in the syllabus.
2. Why is nuclear power non-renewable?
3. State two physical conditions for a good HEP site.
4. What does “intermittent” mean? Give an example.
5. Which renewable source depends on plate boundaries?
6. Give two problems caused by relying on fuelwood.
7. State one benefit and one disadvantage of tidal power.
8. Why do biofuels raise food-supply concerns?
9. In which year did La Rance open?
10. What share of Iceland’s homes are heated by geothermal energy?
11. Why does energy use per person rise with income?

Answers

1. Coal, oil and natural gas.
2. It uses uranium, a mineral stock that runs out.
3. High, reliable rainfall or river flow; a deep, narrow valley to dam (also impermeable rock).
4. Not available all the time, such as solar at night.
5. Geothermal.
6. Health damage from indoor smoke; deforestation and soil erosion; time spent collecting wood.
7. Benefit: tides are predictable. Disadvantage: few suitable sites, and barrages change estuary habitats.
8. Land used for fuel crops such as sugarcane could grow food instead.
10. About 90%.
11. Richer people own more cars and appliances, heat or cool their homes more, and their economies have more industry and services.

Where marks are usually lost

• Listing renewables with no conditions or examples, when the question asks to describe importance.
• Calling nuclear power renewable.
• Leaving out fuelwood, which the syllabus names separately.
• “Evaluate” answers that only list advantages, or never reach a judgement.
• Stating that renewables have no environmental impact; HEP, tidal and biofuels all do.
• Confusing a country’s electricity with its total energy use.
• Generic case-study answers with no named plants, figures or physical reasons.
• Ignoring the “different levels of development” part of a question.
• Misreading graph units, such as reading MW (capacity) as if it were energy produced.

Official syllabus

These notes follow the Cambridge IGCSE Geography (0460) syllabus for examination in 2025 and 2026, Version 2 (published November 2022), Topic 3.5 Energy. Check the current syllabus on the Cambridge International website, and your teacher will confirm which case study your class uses.