Energy and particles · GCSE Physics
Energy resources
Teacher-written GCSE Physics revision on energy resources: renewable versus non-renewable, reliability, base load, environmental impact, and how to compare solar, wind, hydro, nuclear and fossil fuels.
Renewable does not mean always available. Compare reliability, output, start-up time and environmental impact, then match the resource to the job.
The important bits
What you need to know
- 1
Renewable resources are replenished as they are used: solar, wind, hydroelectric, tidal, wave, geothermal and biofuels. Non-renewable resources will run out: coal, oil, gas and nuclear fuel (uranium).
- 2
Fossil fuels are energy-dense, dispatchable and currently supply much of the UK’s electricity, but they release carbon dioxide and other pollutants when burned.
- 3
Nuclear fission does not produce carbon dioxide in generation. It is non-renewable, produces radioactive waste, and has a long start-up time but a steady base-load output.
- 4
Wind and solar have low running emissions but are unreliable: no wind, no power; night and cloud cut solar. They need storage or a back-up resource.
- 5
Hydroelectric and tidal can be reliable in the right geography. Hydro can also store energy by pumped storage, which is useful for meeting peaks.
- 6
Biofuels are renewable if plants are replanted, but they still release carbon dioxide when burned and they compete with land for food.
- 7
Base load is the steady demand that is always there. Peak demand needs resources that can start quickly. A six-mark answer names two resources and compares at least two factors.
- 8
National use also depends on cost, land use, visual and noise impact, and whether the resource can be sited in the UK at useful scale.
Quotations worth analysing
Short evidence. Real method.
“Renewable energy resources can be replenished as they are used.”
Replenished is not the same as constant. Rain refills a dam; the Sun will rise again; that does not mean the wind is blowing at 17:00 on a still January evening.
“Compare reliability, environmental impact and suitability for the job.”
“Renewables are better” is not a conclusion. A small island, a city, and a hospital generator need different mixes.
“Nuclear power can supply a steady base load.”
Base load is the always-on demand. Nuclear and some hydro fit that job; wind does not, unless it is backed by storage or another station.
Go deeper
Resources are a comparison, not a slogan
Renewable does not automatically mean always available. Wind and solar have low running emissions but are unreliable; they need storage or a back-up. Hydro and nuclear can supply a steady base load; nuclear is non-renewable because uranium will run out, but it does not produce carbon dioxide in generation. Coal is dispatchable and energy-dense, and it produces greenhouse gases and particulates. Biofuels are renewable if plants are replanted, but they still release carbon dioxide when burned and they compete with land for food. A six-mark evaluation names two resources, compares reliability, environmental impact and suitability for the job (a small island versus a city), and finishes with a reasoned choice. “Renewables are better” is not a conclusion.
Go deeper
Match the physics of the store to the generator
A thermal power station, fossil or nuclear, boils water, turns a turbine, turns a generator: chemical or nuclear store → thermal → kinetic → electrical. Wind turbines skip the boiler: kinetic store of moving air → electrical. Hydroelectric: gravitational potential of water → kinetic → electrical. Solar cells transfer radiation directly to electrical; solar thermal uses radiation to heat. Once you can name the stores, the evaluation writes itself: a solar farm does nothing useful at midnight, a gas turbine can start in minutes, a nuclear station cannot. Examiners reward that chain more than a memorised list of advantages copied from a poster.
See the idea in action
A town needs 12 MW of electrical power. A wind farm has a maximum output of 18 MW but a typical capacity factor of 0.30, so typical power = 18 × 0.30 = 5.4 MW — not enough on its own. A 12 MW gas station can meet the demand whenever fuel is supplied, but it emits carbon dioxide. A reasoned mix: use the wind farm when the wind blows (typical 5.4 MW) and run the gas station for the remaining 6.6 MW, or store surplus wind in pumped hydro. The numbers show why “just use wind” fails a reliability test even when the nameplate power looks larger than the demand.
Exam technique
Turn knowledge into marks
Name two resources and compare at least two factors: reliability, environment, output, start-up time or cost. Finish with a choice that fits the situation in the question. Never treat renewable as a synonym for reliable.
Common mistakes
Do not give these marks away
- 01
Calling nuclear renewable, or saying solar and wind can always meet base load without storage.
- 02
Writing “renewables are better” without a comparison or a context.
- 03
Forgetting that biofuels release carbon dioxide when burned, or that hydro needs suitable geography.
Which statement about energy resources is correct?
AWind is renewable and always available
BNuclear fuel is renewable because it produces no carbon dioxide in generation
CCoal is non-renewable and can be used to meet demand when needed, but it emits carbon dioxide when burned
DBiofuels are non-renewable because they release carbon dioxide
Show the answer
Coal is non-renewable and can be used to meet demand when needed, but it emits carbon dioxide when burned. Coal is a fossil fuel: dispatchable but polluting. Wind is renewable but not always available. Nuclear is non-renewable. Biofuels can be renewable if replanted.
Quick questions
If this is the bit you searched
Is nuclear power renewable?
No. Uranium will run out, so it is non-renewable. It is still useful for low-carbon base-load electricity, with radioactive waste as the main environmental issue.
Why can wind and solar not supply a country on their own?
They are unreliable: still days, night and cloud. Without storage or a dispatchable back-up, supply will not always match demand.
What is base load?
The minimum electrical demand that is present all the time. Resources with a steady output, such as nuclear or some hydro, are suited to it.
Are biofuels carbon-neutral?
They release carbon dioxide when burned, but growing plants absorb carbon dioxide. They are classed as renewable if replanted, though land use and processing energy still matter.