🏙 Cities
Cities are connected to the grid. Homes, offices and factories use grid electricity, and many also use piped gas. Shops, trains and street lights all run on electricity.
Energy Supply and Demand » Why Energy Mixes Vary
What you'll learn this session
Study time: 30 minutes
Cambridge spec: 10.5.3
- What an energy mix is
- Why the energy mix differs between cities and the countryside
- Why energy mixes differ between countries: physical, economic and political factors, and level of development
- Short examples: Norway, France, Iceland and an LIC that relies on fuelwood
🔒 Unlock Full Course Content
Sign up to access the complete lesson and track your progress!
Unlock This CourseWhat is an energy mix?
No country uses just one type of energy. A country uses a combination of coal, oil, gas, nuclear power, hydroelectric power, wind, solar, fuelwood and more. The energy mix is the proportion of each type of energy that a country uses, often shown as percentages or a pie chart.
Energy mixes are very different from place to place. Two countries can have the same amount of energy but get it from completely different sources. This lesson explains why.
Key terms:
- Energy mix: the proportion of each type of energy used by a country, such as 40% gas, 30% nuclear and 30% wind.
- Grid electricity: electricity sent from power stations along cables (the national grid) to homes, shops and factories.
Variations within a country: urban and rural
The energy mix can differ even inside one country. The biggest split is between towns and the countryside.
🌾 Rural areas
In many LICs, villages are far from the grid. It is expensive to run cables across long distances to a few homes. Families cook and heat with fuelwood, collected for free nearby, or with charcoal.
This is why a country can have a modern grid and still have many people burning wood. Rural homes in HICs are normally on the grid too, but they may also use oil or bottled gas where there is no gas pipe, or wood-burning stoves.
Variations between countries
Four groups of reasons explain why countries have different energy mixes.
1. Physical factors
- Natural resources: a country burns what it has underground. Countries with lots of coal, oil or gas use a lot of it because it is cheap and close.
- Climate: sunny countries can use solar power. Windy coasts suit wind turbines. Cold countries need a lot of energy for heating, and hot countries need it for air conditioning.
- Geology: geothermal energy only works where hot rocks are near the surface, such as volcanic areas.
- Rivers and relief: HEP needs a lot of fast-flowing water and steep valleys to build dams. Flat, dry countries cannot do this.
2. Economic factors
- Wealth: rich countries can afford to build power stations, dams and grids. Poor countries and poor families often cannot.
- Cost of technology: nuclear power stations, offshore wind farms and dams cost a great deal to build. A country with little money may choose cheaper options or rely on fuelwood.
3. Political factors
- Government policy: a government can choose to build nuclear stations, give subsidies to wind and solar, or ban coal.
- Climate targets: countries that have promised to cut emissions move away from coal and oil.
- Attitudes to nuclear power: some countries accept nuclear power. Others do not trust it because of the fear of accidents and waste, so they choose not to use it.
4. Level of development
Poorer countries often use fuelwood and other traditional fuels because they have limited industry and few homes connected to the grid. As a country develops, it builds factories and a grid. Use of coal, oil and gas grows, then in many wealthier countries more electricity and cleaner sources are used.
| Level of development | Typical energy mix |
|---|---|
| LICs | Fuelwood and other traditional fuels make up much of the mix; grid electricity only for some people, mainly in cities |
| MICs | Fast-growing use of coal, oil and gas as industry grows, plus growing use of electricity |
| HICs | Mostly grid electricity, gas and oil; many are adding renewables and nuclear to meet climate targets |
Contrasting short examples
🌊 Norway: HEP
Almost 90% of Norway's electricity comes from HEP. Norway has steep mountains, heavy rain and snowmelt, and many fast rivers: the physical factors are ideal for dams.
⚡ France: nuclear
About two thirds of France's electricity comes from nuclear power. This is a political choice: the government built many nuclear stations from the 1970s to reduce its need for imported oil.
🌋 Iceland: geothermal
Iceland sits on a plate boundary, so hot rocks lie close to the surface. Geothermal energy supplies about two thirds of its primary energy, and heats most homes. Almost all of its electricity comes from HEP and geothermal power.
🌳 An LIC using fuelwood
In Ethiopia, about nine tenths of energy comes from biomass, mainly fuelwood. Most people live in rural areas without a grid, and few can afford electricity or gas cookers.
Worked example
Explain why Iceland and France have very different energy mixes. Iceland has geology that suits geothermal energy: it sits on a plate boundary with hot rocks near the surface (physical). France has few such resources and chose to build nuclear power stations as a government policy to reduce imports (political). Two clear reasons, each linked to a factor, would score well.
Common mistakes
Saying "it is because they are rich" without more detail. Say which factor applies and how. Another mistake is thinking a country with rivers will always use HEP: it also needs the money to build the dams. Do not mix up the examples: Norway is HEP, France is nuclear, Iceland is geothermal.
Exam-style question
Fig. 1.1 shows the energy mix of two countries. The data is made up.
| Energy type | Country X (%) | Country Y (%) |
|---|---|---|
| Fuelwood and charcoal | 75 | 2 |
| Oil and gas | 20 | 45 |
| Coal | 3 | 15 |
| Nuclear | 0 | 18 |
| HEP, wind and solar | 2 | 20 |
(a) Define the term energy mix. [2 marks]
(b) Describe two differences between the energy mixes of Country X and Country Y. [2 marks]
(c) Give one reason why many people in rural areas of LICs use fuelwood. [1 mark]
(d) Explain why different countries have different energy mixes. [6 marks]
Model answer
(a) The proportion (1) of each type of energy that a country uses (1).
(b) Country X uses 75% fuelwood and charcoal but Country Y uses only 2% (1). Country Y uses nuclear power (18%) but Country X uses none (1). [Other correct comparisons with data also score.]
(c) Rural areas are not connected to the grid, and fuelwood is cheap or free to collect (1).
(d) Level 3 (5-6 marks): Clear explanation of several factors, with examples. Level 2 (3-4 marks): Two factors explained, or several described only. Level 1 (1-2 marks): A simple statement of one factor.
Example full-mark answer: Physical factors matter because countries use what they have. Norway has steep valleys and fast rivers, so it uses HEP, while Iceland has hot rocks near the surface because of its volcanoes, so it uses geothermal energy. Economic factors matter too: dams, nuclear stations and grids are expensive, so poorer countries may rely on fuelwood. Political decisions also change the mix. France built nuclear power stations as government policy, but other countries avoid nuclear power because they fear accidents. Finally, level of development matters: LICs use more fuelwood, while HICs have more grid electricity.
Exam tip
For "Explain why" questions with six marks, name a factor, say how it affects the energy mix, and add a country example. Use at least three different factors.