Energy resources, electricity and demand
Classify energy resources, outline how they generate electricity and weigh their benefits against limits and changing demand.
This original StudyForA sequence supports Cambridge IGCSE Environmental Management 0680 Topics 1–4 for exams in 2027, 2028 and 2029. Named local examples are chosen by the learner and centre; verify current conditions and local context with reliable sources. It is not a Cambridge paper, official grade or complete course.
Before you begin
- Use the 2027–2029 syllabus and check your exam year and centre's entry arrangements. Topics 1–4 are taught on this page; Topics 5–7 are still being built.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
What turns a turbine in a hydroelectric station?
What you will learn
- Classify energy resources, outline how they generate electricity and weigh their benefits against limits and changing demand.
- Use evidence from an unfamiliar case to explain a cause-and-effect link and justify a suitable response.
Understand the resource categories
Coal, petroleum (oil) and natural gas (methane) form from ancient organic material buried and changed over long periods under heat and pressure. They are finite fossil fuels. Uranium used for nuclear power is also classified as non-renewable in this syllabus.
Renewable (non-finite) resources listed here are bioethanol, biomass, biogas, wood, geothermal, hydro-electric, tidal, wave, solar and wind power. Renewable does not mean impact-free: location, materials, land, water and reliability still matter.
Trace energy conversion to electricity
Many thermal power stations burn fuel to heat water; steam turns a turbine connected to a generator. Nuclear power also heats water, but energy comes from fission rather than combustion. Hydroelectricity uses moving or falling water to turn turbines; wind and tidal flows can drive turbines directly.
Solar photovoltaic cells convert light to electrical energy. Geothermal systems use heat from underground; biofuels release stored chemical energy. State the resource and the conversion steps instead of saying that a source simply 'makes electricity'.
Explain advantages, limitations and demand
Compare reliability, controllability, cost, emissions, land and water needs, waste, suitable location and effects on communities. A resource can have low operating emissions yet still have construction or habitat impacts.
Energy demand is affected by transport, personal and national wealth, climate, population size, industry, supply disruption or unreliability, and resource scarcity. These factors can interact; cold weather, for example, may raise heating demand where people can afford and access it.
Sources for this lesson
Pause and explain
A cold spell raises energy demand. Which syllabus factor explains this?
Worked example
A region wants electricity from wind, hydroelectricity and a fossil-fuel station. Explain one conversion step for each and one factor that could affect where each is used.
Show the worked solution
- Wind turns turbine blades connected to a generator; suitable wind and grid connection matter.
- Moving water turns a turbine; dependable flow, terrain and ecosystem effects matter.
- Combustion heats water to make steam that turns a turbine; fuel supply, emissions and cost matter.
Answer All three can drive a generator by different routes, but each needs suitable conditions. Wind needs reliable wind, hydro depends on water and terrain, while the fossil-fuel station needs fuel and creates combustion emissions.
Try a topic test
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Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
A town uses natural gas to generate electricity. Describe the conversion chain and identify one environmental limitation.
Give me a hint
Follow chemical energy through heat, steam, turbine and generator.
Compare my reasoning
- Combustion of natural gas releases heat.
- The heat can boil water; steam turns a turbine connected to a generator.
- Combustion releases carbon dioxide, and fuel extraction and supply have further site-specific impacts.
Natural gas is burned to heat water; steam turns a turbine and generator. Carbon dioxide emissions are a key limitation, alongside extraction and supply impacts.
Look for these in your work
- Conversion sequence complete
- Generator included
- Limitation linked to combustion
Choose two renewable resources from the syllabus and compare one benefit, one limitation and one condition needed for electricity generation.
Give me a hint
A valid comparison recognises that renewable resources still depend on place and design.
Compare my reasoning
- Select two named resources, such as wind and hydro-electric power.
- Explain a benefit and a limitation for each, supported by the mechanism or setting.
- State the condition for use: wind exposure for wind power; water flow and suitable terrain for hydroelectricity.
Wind power avoids fuel combustion during generation but depends on suitable wind and can affect landscapes or habitats. Hydroelectricity can provide controllable output where water and terrain allow, but dams alter rivers and habitats. Actual effects depend on site design.
Look for these in your work
- Two syllabus resources named
- Benefits and limits compared
- Location condition stated
An industrial region's energy demand is rising while supply is unreliable. Use at least three syllabus factors to explain the change and recommend what evidence planners should gather before choosing a new resource.
Give me a hint
Include demand drivers and resource-specific location, reliability and impact evidence.
Compare my reasoning
- Industry and population can increase total demand; wealth can raise household and transport use.
- Unreliable supply can increase demand for backup or storage, while climate may create seasonal peaks.
- Planners need local resource availability, cost, emissions, water and land needs, reliability and community impacts before choosing.
Industry, population, wealth, climate and unreliable supply can all affect demand. A resource choice needs evidence about local supply conditions, total cost, reliability, environmental impacts and who is affected.
Look for these in your work
- At least three demand factors applied
- Supply reliability considered
- Evidence requested before recommendation
Common mistakes
- Calling a resource renewable and therefore impact-free
- Confusing energy conversion with the energy source
- Ignoring uranium when classifying non-renewable resources
- Assuming demand depends only on population
What can you explain now?
Which list contains only non-renewable resources in this syllabus?
Compare with the explanation
Fossil fuels and nuclear power using uranium
The correct answer is “Fossil fuels and nuclear power using uranium”. The alternatives “Wind, solar and tidal power” and “Biomass, wood and hydro-electric power” do not match the syllabus concept. Classify energy resources, outline how they generate electricity and weigh their benefits against limits and changing demand.
After trying it yourself, choose your next review. This is your self-assessment.
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Make it stick
Classify the syllabus energy resources, describe how two generate electricity and explain three influences on demand.
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.