IB ESS HL 7.2 Energy Use and Management Question Bank

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.

Example - Solar:

Advantages of using solar energy:
a. Solar energy is a renewable resource that will never run out;
b. Solar energy produces no greenhouse gas emissions or air pollutants, reducing environmental impact;
c. Once installed, solar panels can provide free electricity for many years / leading to long

term cost savings;
d. Solar panels require minimal maintenance and have a long lifespan / making them a reliable energy source;
e. Using solar energy can reduce dependence on fossil fuels and foreign energy sources / increasing energy security.

Disadvantages of using solar energy:
f. Solar energy is dependent on sunlight, making it inconsistent and unreliable during cloudy or night time conditions;
g. The initial investment in solar panels and installation can be expensive / deterring some individuals or businesses from adopting solar energy;
h. Solar panels require a significant amount of space for installation / limiting their feasibility in densely populated areas;
i. Storing excess solar energy (for use during periods of low sunlight) can be costly and technologically challenging;
j. The production and disposal of solar panels can have environmental consequences / such as the use of toxic materials and waste generation.

Example - Wind:

Advantages of using wind as a source of energy:
a. Wind is a renewable energy source that will never run out, unlike fossil fuels;
b. Wind energy production does not produce greenhouse gas emissions/air pollutants, reducing the impact on the environment;
c. Once wind turbines are installed, the operational costs are relatively low compared to traditional energy sources;
d. Using wind energy reduces reliance on imported fossil fuels, increasing energy security;
e. The wind energy industry creates jobs in manufacturing, installation, maintenance, and other related sectors.

Disadvantages of using wind as a source of energy:
f. Wind energy production is dependent on wind availability, which can be inconsistent and unpredictable;
g. Wind farms require significant land area, which can lead to conflicts with other land uses such as agriculture or wildlife habitats;
h. Some people find wind turbines visually unappealing, leading to aesthetic concerns in certain locations;
i. Wind turbines can generate noise during operation, which may be a concern for nearby residents;
j. Wind turbines can pose risks to birds and bats through collisions or habitat disruption, requiring careful siting and mitigation measures.

Example - hydropower
Advantages of using hydropower as a source of energy:
a. Hydropower relies on the natural water cycle, making it a sustainable and renewable energy option;
b. Hydropower produces minimal greenhouse gas emissions compared to fossil fuels, contributing to lower carbon footprints;
c. Hydropower plants can provide a stable and consistent energy supply, as water flow can be controlled to meet demand;
d. Once the infrastructure is in place, hydropower can be a cost-effective energy source with low operational costs;
e. Hydropower projects can offer additional benefits such as flood control, irrigation, and recreational opportunities.
Disadvantages of using hydropower as a source of energy:
f. Large-scale hydropower projects can disrupt ecosystems, alter river flows, and impact aquatic habitats;
g. Building dams for hydropower projects may require the displacement of communities living in the affected areas;
h. Dam failures can have catastrophic consequences, leading to flooding, property damage, and loss of life;
i. Not all regions have suitable conditions for hydropower development, limiting its widespread adoption;
j. Sediment buildup in reservoirs can reduce storage capacity and affect downstream ecosystems, requiring ongoing management and maintenance efforts.

Note to examiners: Award credit in similar way for other valid renewable energy sources. Do not credit nuclear - it is non-renewable.
If more than one source is addressed, just credit the highest scoring.

Marking guidance:

Award 3 max for responses that do not name a specific renewable source
(2 marks max for disadvantages, 2 marks max for advantages)