4.2.7Electrochemistry
Comparing Energy Resources — Cambridge IGCSE Chemistry 0620 Revision Notes & Topical Questions
5 min read 4 parts Lesson 19 of 20 Unit quiz
Section 1 of 4Criteria for Comparison
No single energy resource is best in every situation, so each must be judged against clear criteria.
Cost
- Includes the cost of building, running and maintaining the power station, as well as any fuel cost.
Reliability
- How constant the supply is; wind and solar output depend on the weather and the time of day.
Environmental impact
- Includes greenhouse gas emissions, habitat disruption, land use and the disposal of waste.
Start-up time
- Some stations can be started quickly to meet sudden demand, while others take many hours to begin producing power.
Section 2 of 4Comparing Resources
Each resource has advantages and disadvantages that must be weighed together.
Comparing Resources
Location
- A windy coastline suits wind turbines, while a sunny region suits solar panels.
Demand
- Power stations that respond quickly are needed to meet sudden peaks in demand.
Economics
- Governments weigh the cost of building new stations against long-term running costs and carbon targets.
Energy mix
- Most countries use a range of resources, so a failure in one source does not cut off the whole supply.
| Resource | Advantage | Disadvantage |
|---|---|---|
| Fossil fuel | Reliable and easy to store | Releases CO₂ and adds to global warming |
| Nuclear | Large output with low carbon emissions | Produces radioactive waste and is expensive to build |
| Wind | No fuel cost and no emissions when running | Intermittent and needs a large land area |
| Solar | No emissions and no fuel needed | Output stops at night and depends on sunshine |
| Hydroelectric | Responds quickly and needs no fuel | Needs suitable valleys and can disrupt ecosystems |
Section 3 of 4Evaluating a Decision
A good evaluation links each criterion to the situation being considered.
1
Identify the criteria that matter most for the situation, such as cost, reliability or emissions.
2
Compare each energy resource against those criteria, using facts and evidence from data where available.
3
Weigh the advantages against the disadvantages and state the trade-offs made in the choice.
4
Reach a justified conclusion and state the limitations of the evidence used to reach it.
Section 4 of 4Exam Checklist & Tips
4.2.7 – Key Points for the Exam
- Reliability How consistently an energy resource can supply power when it is needed.
- Intermittent Available only at certain times, such as when the wind blows or the Sun shines.
- Carbon dioxide A greenhouse gas released when fossil fuels are burned.
- Radioactive waste Waste from nuclear reactors that emits radiation and must be stored safely.
- Trade-off A decision in which gaining one advantage means accepting a disadvantage elsewhere.
Common Mistakes
- Saying one resource is best in every situation without stating which criteria were used.
- Describing wind power as having no environmental impact at all; it affects land use and wildlife.
- Ignoring start-up time or reliability when comparing sources that must supply a constant demand.
- Stating that nuclear power produces no waste; it produces radioactive waste that must be stored safely.
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