IB ESS SL 7.2 Energy Sources Uses and Management Questions
Practise IB ESS SL 7.2 by calculating energy trends and evaluating how geography, availability, cost and policy shape energy choices.
- Syllabus
- First assessment 2026
- Course
- ESS SL
- Level
- SL
Exam points
- Calculate average annual demand, fossil-fuel share and renewable contribution from energy figures.
- Explain a changing energy mix through geography, availability, imports, technology, policy and price.
- Evaluate named energy sources by balancing reliability, carbon, pollution and ecosystem impacts.
Covered syllabus points
Question 1
[Maximum number: 6]
Outline the range of energy resources available to society.
Range:
e.g. renewability:
renewable energy resources are replenished within a similar time-scale to that at which they are extracted;
resources may be renewable through chemical fixation of solar energy / through direct use of solar heat/light/ quite independently of solar energy;
non-renewable energy resources cannot be replenished within a similar timescale to that at which they are extracted;
replenishable energy resources may be dependent on solar energy for replenishment but do not involve its chemical fixation (eg hydropower, 'solar' power, wind power, geothermal, tidal etc);
N.B. This last category of 'replenishable' is often included within 'renewable' energy resources in the literature, so do not penalise responses that do the same.
e.g. cost:
costs of energy resource may come from extraction, production, transport, storage, utilisation;
some have high set-up cost but low production cost, and vice versa;
there is economy of scale where cost can be reduced through centralisation;
cost can vary considerably dependent on time and location;
Examples:
Marking guidance:
Award [1 max] for each named example with some comment identifying its position within the chosen range. Appropriate comments may vary considerably but should be of equal validity, relevance and significance to those shown below:
biofuel/charcoal/fuelwood/biogas - is renewable replenished through solar energy/photosynthesis/has relatively low extraction/production costs/most readily available to rural ELDC communities;
hydroelectric energy - is renewable/replenishable dependent on solar energy / has high set- up but low maintenance cost / cost effectiveness highly dependent on location;
solar energy - is renewable/replenishable utilising light or heat of the sun / most direct renewable use of solar energy / high set-up costs but low maintenance / cost-effectiveness quite dependent on latitude/climate;
wind energy - is renewable/replenishable dependent on solar energy/extraction has no impact on its replenishment/relatively low cost but inconsistent production/adaptable for small or large scale production;
tidal energy - is renewable/replenishable but not dependent on solar energy/dependent on planetary rotation/gravity / fairly high installation cost but relatively low maintenance / limited to coastal location with sufficient tidal range;
geothermal energy is renewable/replenishable but not dependent on solar energy/replenished by heat from earth's core / can be relatively cheap but very dependent on location / recently become cost effective through technological development;
requires an underground/close to the surface heat source;
fossil fuels are non-renewable since their formation takes vast amounts of time compared to rates of extraction / although large reserves do still exist, stocks are depleting / cost will vary considerably dependent on a regions available reserves / cost of extraction very variable dependent on sources;
Other examples of energy sources with appropriate comments may be credited.
For full credit, a response should identify the RANGE over which energy sources are being considered and then identify the position within this range for a number of examples. The most obvious range might be their renewability, but responses that compare/identify sources over a range of relative cost/efficiency/availability/current consumption/current production etc should equally be credited.
Award 2 max for outlining the range, and 4 max for naming and correctly identifying the position of different energy resources within this range.
Question 2
[Maximum number: 10]
Question (a)
(a)
State three reasons why global energy use continues to rise.
[ 3 ]
growth in human population;
increase in affluence/wealth (resulting in more energy intensive lifestyles);
technological developments (eg increased use of electrically/ fossil fuel powered appliances/ machines);
increased travel (eg more air travel);
increased industrialization (especially in LEDCs);
increased international trade/globalization;
Question (b)
(b)
Compare and contrast the reasons for the choice of energy sources used in two named countries.
[ 7 ]
Marking guidance:
Award [1 max] for two named countries with at least one valid energy choice each (reasons not necessary for this mark).
Reasons may include:
Availability:
eg location (eg coastal for tidal/offshore wind / thin crust for geothermal);
eg topography (mountains/rivers for HEP);
eg geology (reserves of coal/oil/gas);
Economic:
High standard of living/technological development requires high capacity variety of
National wealth may limit choice of affordable technology/resources;
countries may have strong historical traditions/value systems/international reputations to maintain;
historical events may influence decisions (eg countries experiencing nuclear disasters / oil embargoes;
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sources;
Cultural:
Political:
countries may need to respond to changing values in their own population eg (rising ecocentrism);
countries may need to meet international agreements / maintain energy security;
technological: tech development may make new choices available;
countries may or may not have tech expertise for certain choices;
Award [6 max] for reasons valid for the countries identified. Award [4 max] if there is no clear links (of comparison or contrast between the countries).
Total: [20]
Question 3
[Maximum number: 9]
The future growth of human populations is unlikely to be limited by the availability of energy resources. However, they could easily be limited by the impacts of energy production.
Discuss the validity of this statement.
The following guide for using the markbands suggests certain features that may be offered in responses. The five headings coincide with the criteria given in each of the markbands (although "ESS terminology" has been conflated with "Understanding concepts"). This guide simply provides some possible inclusions and should not be seen as requisite or comprehensive. It outlines the kind of elements to look for when deciding on the appropriate markband and the specific mark within that band.
Answers may include:
- understanding concepts and terminology of human population growth, limiting factors, "limits to growth", renewable/non-renewable energy, sustainable development;
natural capital/income, carrying capacity, ecological footprints, energy choice, energy security, impacts of climate change, air, water pollution, soil degradation on food production/water availability/disease, etc, predictive models on growth and resource availability;
- breadth in addressing and linking longevity/sustainability of a range of energy sources with human population growth and a range of impacts of energy production from extraction to transportation to infrastructure with a range of limits to human population growth, etc;
- examples of non-renewable energy sources eg oil, coal, fracking, natural gas, nuclear, etc and renewable sources eg hydropower, geothermal, wind, wave, tidal, etc and impacts of energy production eg climate change/shifting biomes/agricultural conditions/food production/water availability/scarcity/disease and possible limits to growth eg pollution, disease, potable water, arable land, food, etc;
- balanced analysis of likelihood of energy itself becoming a limiting factor to human population growth compared to a variety of limiting factors resulting from energy production, including counter arguments (possible sustainability of energy choices), etc;
- a conclusion that is consistent with, and supported by, analysis and examples given eg "despite the development of sustainable energy that would prevent energy itself becoming a limiting factor, countries still persisting in their dependence on fossil fuels may well impair the availability of food and water and spread of disease, each of which could soon become a limiting factor to the growth of human populations";
Please see markbands on page 17.
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