IB ESS HL 7.2 Energy Sources Uses and Management Questions
Practise IB ESS HL 7.2 by analysing energy trends and evaluating security, affordability, reliability and environmental trade-offs.
- Syllabus
- First assessment 2026
- Course
- ESS HL
- Level
- HL
Practise IB ESS HL 7.2 by analysing energy trends and evaluating security, affordability, reliability and environmental trade-offs.
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 region's 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.
State three reasons why global energy use continues to rise.
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;
Compare and contrast the reasons for the choice of energy sources used in two named countries.
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);
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 are no clear links (of comparison or contrast between the countries).
Total: [20]
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.
• 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";
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.
These are possible inclusions, not required points. Assess the response using the official Section B, part (c) markbands below.
| Marks | Level descriptor |
|---|---|
| 0 | The response does not reach a standard described by the descriptors below and is not relevant to the question. |
| 1–3 | The response contains: • minimal evidence of knowledge and understanding of ESS issues or concepts • fragmented knowledge statements poorly linked to the context of the question • some appropriate use of ESS terminology • no examples where required, or examples with insufficient explanation/relevance • superficial analysis that amounts to no more than a list of facts/ideas • judgments/conclusions that are vague or not supported by evidence/argument. |
| 4–6 | The response contains: • some evidence of sound knowledge and understanding of ESS issues and concepts • knowledge statements effectively linked to the context of the question • largely appropriate use of ESS terminology • some use of relevant examples where required, but with limited explanation • clear analysis that shows a degree of balance • some clear judgments/conclusions, supported by limited evidence/arguments. |
| 7–9 | The response contains: • substantial evidence of sound knowledge and understanding of ESS issues and concepts • a wide breadth of knowledge statements effectively linked with each other, and to the context of the question • consistently appropriate and precise use of ESS terminology • effective use of pertinent, well-explained examples, where required, showing some originality • thorough, well-balanced, insightful analysis • explicit judgments/conclusions that are well-supported by evidence/arguments and that include some critical reflection. |
Section B, part (c) markbands (official markscheme p17)
State three reasons why global energy use continues to rise.
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;
Examine the driving factors behind the changing energy choices of different countries using named examples.
Answers may demonstrate:
• understanding concepts & terminology of energy choices and security; renewable energy; solar; biomass; hydropower; wind; wave; nuclear; availability and reliability of energy supply; scientific developments; economic considerations; cultural factors; political dependencies; climate change; urban air pollution; acid deposition; water pollution; human population dynamics; ecological footprint; sustainability; EVSs;
• breadth in addressing and linking driving factors, including political, scientific, socio-economic, environmental, geographical, population dynamics, technological and cultural factors, with changes in energy choices for a range of countries;
• examples include a range of countries with various reasons/driving factors for changing their energy choices;
• balanced analysis how and to what extent driving factors for changing energy choices differ or are similar in a range of countries.
• a conclusion that is consistent with, and supported by analysis and examples given eg Although local parameters in terms of geography, economics and cultural values create a diverse array of factors affecting change in energy choices amongst different countries, the global increase in awareness of climate change and its relationship with fossil fuel use has led an increasing number of countries to move towards more sustainable energy sources.
| Marks | Level descriptor |
|---|---|
| 0 | The response does not reach a standard described by the descriptors below and is not relevant to the question. |
| 1–3 | The response contains: • minimal evidence of knowledge and understanding of ESS issues or concepts • fragmented knowledge statements poorly linked to the context of the question • some appropriate use of ESS terminology • no examples where required, or examples with insufficient explanation/relevance • superficial analysis that amounts to no more than a list of facts/ideas • judgments/conclusions that are vague or not supported by evidence/argument. |
| 4–6 | The response contains: • some evidence of sound knowledge and understanding of ESS issues and concepts • knowledge statements effectively linked to the context of the question • largely appropriate use of ESS terminology • some use of relevant examples where required, but with limited explanation • clear analysis that shows a degree of balance • some clear judgments/conclusions, supported by limited evidence/arguments. |
| 7–9 | The response contains: • substantial evidence of sound knowledge and understanding of ESS issues and concepts • a wide breadth of knowledge statements effectively linked with each other, and to the context of the question • consistently appropriate and precise use of ESS terminology • effective use of pertinent, well-explained examples, where required, showing some originality • thorough, well-balanced, insightful analysis • explicit judgments/conclusions that are well-supported by evidence/arguments and that include some critical reflection. |
Section B, part (c) markbands (official MS p18)
Figure:Electricity generation in Costa Rica by energy source (1990-2016)
Identify one possible reason why there has been a change in the quantity of electricity generated from wind as shown in Figure 9(a).
improved/cheaper technology;
change in environmental values / increase in popularity; greater awareness of benefits of using wind power; government policy / to achieve country's goal to become carbon neutral; increasing demand due to growing population
Do not accept 'wind power is renewable/unlimited/more sustainable/a green energy source/more viable over the long term/produces less pollution'. Do not accept 'changes in wind current'.
Do not accept only 'greater investment/funds available for wind power/renewables'.
Suggest three different strategies that may be used to manage global energy consumption.
increase production of energy from renewable resources/ wind /solar/tidal/nuclear;
increase efficiency of energy usage through technological development;
increase awareness of energy-saving practice through education/campaigns;
address issues of energy distribution through import/export;
promote exploitation of locally appropriate/available energy sources to reduce need for import/export;
seek new reserves of non-renewable energy resources/fossil fuels;
provide technical support/economic subsidy for renewable/clean/efficient energy supply;
imposing legislated caps/taxes/limitations to energy consumption/C production;
anti-natalist policies reduce population growth and energy consumption;
reducing energy consumption through recycling/reusing resources (recycling uses energy but less);
Accept reasonable alternative responses.
Question addresses strategies of global application Credit should be given for broad approaches and not specific actions.
Eg "use public transport" is not acceptable, but "promoting/raising awareness of/subsidising public transport" would be acceptable.
Eg "switching off lights" is not acceptable, but "raising awareness/promoting energy conservation" would be acceptable.
Increasing concern for energy security is likely to lead to more sustainable energy choices.
Discuss the validity of this statement, with reference to named countries.
• understanding concepts & terminology of energy security; renewable/ non-renewable energy; sustainability; fossil fuels; nuclear; solar, biomass, hydropower, wind, wave, tidal or geothermal energy; emissions; etc
• breadth in addressing and linking different countries' issues of energy security with their energy choices and the relative sustainability of renewable/ non-renewable energy sources; etc
• examples of renewable/non-renewable energy sources; countries' energy choices; issues of energy security; impacts of exploiting energy resources; etc
• balanced analysis of whether energy choices driven by concern for energy security are more or less sustainable; acknowledging relevant counter-arguments/alternative viewpoints;
• a conclusion that is consistent with, and supported by analysis and examples given eg although more sustainable renewable energy choices will usually provide energy security, in some countries, because of local availability of non-renewable sources, the concern for security has been met by less sustainable sources eg US exploitation of tar sands;
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.
NB This is only an example of a possible conclusion. Candidates' conclusions do not have to agree.
Use the official Section B, part (c) markbands below.
| Marks | Level descriptor |
|---|---|
| 0 | The response does not reach a standard described by the descriptors below and is not relevant to the question. |
| 1–3 | The response contains: • minimal evidence of knowledge and understanding of ESS issues or concepts • fragmented knowledge statements poorly linked to the context of the question • some appropriate use of ESS terminology • no examples where required, or examples with insufficient explanation/relevance • superficial analysis that amounts to no more than a list of facts/ideas • judgments/conclusions that are vague or not supported by evidence/argument. |
| 4–6 | The response contains: • some evidence of sound knowledge and understanding of ESS issues and concepts • knowledge statements effectively linked to the context of the question • largely appropriate use of ESS terminology • some use of relevant examples where required, but with limited explanation • clear analysis that shows a degree of balance • some clear judgments/conclusions, supported by limited evidence/arguments. |
| 7–9 | The response contains: • substantial evidence of sound knowledge and understanding of ESS issues and concepts • a wide breadth of knowledge statements effectively linked with each other, and to the context of the question • consistently appropriate and precise use of ESS terminology • effective use of pertinent, well-explained examples, where required, showing some originality • thorough, well-balanced, insightful analysis • explicit judgments/conclusions that are well-supported by evidence/arguments and that include some critical reflection. |
Section B, part (c) markbands (official markscheme p16)
Outline two advantages and two disadvantages of nuclear power as a choice of energy production.
Advantages [2 max]:
a. Low greenhouse gas emissions, reducing climate impacts;
b. High energy output/efficient for small amount of fuel;
c. Stable/reliable/consistent source of energy, increasing energy security;
d. Once built, it is relatively cheap to produce energy;
e. Low to no air pollution/SOx/NOx/particulate matter;
Disadvantages [2 max]:
f. It is a non-renewable resource so the supply is finite;
g. Safety/health concerns with exposure to radioactivity/nuclear accidents;
h. Radioactive waste can cause environmental degradation;
i. Thermal pollution can affect aquatic ecosystems;
j. Expensive to construct and decommission / expensive to manage/store radioactive waste;
k. Requires highly skilled labor/expertise which can limit use;
l. Public concerns/opposition to nuclear proliferation/creation of nuclear weapons;