IGCSE Physics / Energy resources and electricity generation
Advantages and disadvantages of energy resources
Edexcel International GCSE Physics (4PH1), chapter 17: Energy resources and electricity generation, specification point 4.19P. Free lesson.
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Energy resources have different effects on reliability, the environment and cost. Comparing these clearly helps you make a balanced judgement about how electricity should be generated.
What renewable means
A renewable energy resource is replaced naturally, so it will not run out. Renewable does not mean that a resource is always available or that it is recycled. Wind is renewable, for example, but it only generates electricity when the wind blows. Fossil fuels and nuclear fuel are non-renewable because they will run out. Wind, water, solar and geothermal energy are renewable.
How fossil fuels, nuclear and wind compare
Compare resources using specific differences. Reliability and start-up time affect whether a station can respond when demand changes. Environmental effects and costs also matter, so avoid general statements such as “it causes pollution” or “it is expensive”. Reliability and start-up: fossil fuel and nuclear stations can run when needed. Gas stations start quickly, coal takes longer, and nuclear is slowest to start. Wind depends on the weather and cannot be switched on when demand rises. Emissions and other harm: burning fossil fuels releases carbon dioxide, which adds to global…
How hydroelectricity and solar cells compare
Both are renewable and release no carbon dioxide while running, but their reliability and effects on land differ. These differences help you compare two renewable resources rather than simply saying they are both renewable. A hydroelectric dam can generate electricity whenever it is needed and starts very quickly. However, it floods a valley, destroying habitats and sometimes homes. Solar cells only generate in daylight. A large solar farm covers a large area of land. Both methods cost a lot to build and very little to run.
How to write a balanced judgement
For an evaluation, compare both options directly and explain why each advantage or disadvantage matters. Develop at least one point by linking it to the effect on electricity supply, then make a judgement that follows from your comparisons.
Example: wind instead of gas
Wind is better for the environment, but a country also needs electricity when the wind is not blowing. A gas station can provide a more reliable supply at those times. Wind is renewable, so it will not run out, whereas gas is non-renewable. Burning gas releases carbon dioxide, which adds to global warming. A wind farm releases none while running. Wind farms only generate when the wind blows, so their output cannot be matched to demand. A gas station can start quickly when demand rises, making it more reliable. Wind farms need large areas of land or sea, and some people object to their noise…
Comparing nuclear power with coal
A clear comparison names what each method releases or leaves behind, then explains why it matters. Advantage of nuclear: it releases no carbon dioxide while running, so it does not add to global warming. Disadvantage of nuclear: it leaves radioactive waste, which stays dangerous for a very long time and can cause cancer.