You are viewing a free preview of this lesson.
Subscribe to unlock all 10 lessons in this course and every other course on LearningBro.
This lesson covers non-renewable energy sources — fossil fuels and nuclear power — as required by AQA GCSE Design and Technology (8552), Section 3.1.2. Understanding where energy comes from and how it is generated is essential for evaluating the environmental impact of products and manufacturing processes.
A non-renewable energy source is one that will eventually run out because it is consumed faster than it can be replaced. The three main fossil fuels — coal, oil and natural gas — formed over millions of years from the remains of ancient organisms. Once burned, they cannot be reformed on a human timescale.
Coal is a solid fossil fuel formed from ancient plant material compressed under heat and pressure over millions of years. It is burned in power stations to generate electricity.
| Advantage | Disadvantage |
|---|---|
| Reliable — provides a steady base-load supply | Produces the highest CO₂ emissions per unit of energy of all fossil fuels |
| Abundant global reserves (estimated 100+ years) | Mining causes habitat destruction and air pollution |
| Existing infrastructure for coal-fired power stations | Burning releases sulphur dioxide (SO₂), contributing to acid rain |
| Creates jobs in mining communities | Coal ash contains toxic heavy metals |
Oil is a liquid fossil fuel extracted by drilling. It is refined into fuels (petrol, diesel, jet fuel) and is the raw material for most plastics.
| Advantage | Disadvantage |
|---|---|
| High energy density — excellent for transport | Combustion releases CO₂, contributing to climate change |
| Versatile — fuels, plastics, lubricants, chemicals | Oil spills devastate marine ecosystems |
| Well-established global distribution network | Finite resource — estimated 50 years of proven reserves |
| Relatively easy to transport (pipelines, tankers) | Price volatility affects manufacturing costs |
Natural gas (mainly methane, CH₄) is extracted from underground reserves and used for heating, cooking and electricity generation.
| Advantage | Disadvantage |
|---|---|
| Cleanest-burning fossil fuel — lower CO₂ than coal or oil | Still produces CO₂ and contributes to climate change |
| Fast start-up — gas turbines can respond quickly to demand | Methane leaks during extraction are a potent greenhouse gas |
| Efficient combined-cycle gas turbines (CCGT) | Finite resource — estimated 50–60 years of proven reserves |
| Lower SO₂ emissions than coal | Fracking (hydraulic fracturing) is controversial — risk of groundwater contamination |
AQA Exam Tip: When comparing fossil fuels, always rank them by CO₂ emissions: coal (highest) > oil > natural gas (lowest). This is a frequently tested fact.
Nuclear power generates electricity by splitting atoms of uranium (or plutonium) in a process called nuclear fission. The heat produced turns water into steam, which drives turbines connected to generators.
| Advantage | Disadvantage |
|---|---|
| No CO₂ emissions during operation | Produces radioactive waste that remains hazardous for thousands of years |
| Reliable base-load power (runs 24/7) | High construction costs — nuclear power stations cost billions to build |
| High energy density — a small amount of fuel produces a huge amount of energy | Risk of nuclear accidents (e.g. Chernobyl 1986, Fukushima 2011) |
| Long operational life — stations can run for 40–60 years | Decommissioning is extremely expensive and time-consuming |
| Reduces dependence on fossil fuels | Uranium is a finite resource (though reserves are large) |
AQA Exam Tip: Nuclear power is technically non-renewable (uranium will eventually run out), but it does not produce greenhouse gases during operation. Examiners may test whether you understand this distinction.
| Impact | Description |
|---|---|
| Climate change | Burning fossil fuels releases CO₂, trapping heat in the atmosphere |
| Acid rain | SO₂ and NOₓ from coal and oil combustion dissolve in rainwater, damaging buildings, forests and lakes |
| Air pollution | Particulate matter from combustion causes respiratory diseases |
| Oil spills | Tanker accidents and pipeline leaks contaminate oceans and coastlines |
| Radioactive waste | Nuclear waste must be stored securely for thousands of years |
| Habitat destruction | Mining, drilling and infrastructure construction destroy natural habitats |
As a D&T student, you should consider:
AQA Exam Tip: A common 4-mark question asks you to compare two energy sources. Structure your answer as a table with advantages and disadvantages for each, then state which is more suitable for a given scenario and why.