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.

Exam points

Interpret energy-mix charts to identify source shares and calculate changes in demand or consumption.
Compare named countries' energy choices using resource access, cost, technology, policy and environmental impacts.
Evaluate source sustainability by weighing emissions and ecosystem impacts against cost, reliability and supply.
Assess energy conservation through efficiency technology and behaviour changes that reduce use or imports.
Evaluate HL energy security through affordability, reliable supply, diversification and dependence on fuel imports.
Evaluate nuclear power's low-carbon output against finite reserves, accident risks and radioactive waste.

Covered syllabus points

7.2.1—Energy source types 7.2.2—Global energy consumption rising 7.2.3—Energy source sustainability 7.2.4—Country energy choices 7.2.5—Intermittent energy production 7.2.6—Energy conservation and efficiency 7.2.7 (HL)—Energy security 7.2.8 (HL)—Fossil fuel dependence 7.2.9 (HL)—Nuclear power 7.2.10 (HL)—Battery storage requirements

[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 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.

[Maximum number: 10]

(a)

State three reasons why global energy use continues to rise.

[ 3 ]

(b)

Compare and contrast the reasons for the choice of energy sources used in two named countries.

[ 7 ]

[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.

• 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)

All question bank results loaded

Covered syllabus points

Question 1

Question 2

Question (a)

Question (b)

Question 3