Overview
What you’ll learn
- Name the main resources and sort them into renewable and non-renewable.
- Match resources to their uses — electricity, heating, cooking, transport.
- Attach the right environmental issues to each resource, including decommissioning.
- Explain reliability and why calm, dull days still need backup generation.
- Describe how the UK energy mix has shifted from coal towards renewables.
- Convert between joules and kilowatt-hours and price up household energy.
Specification checklist (AQA Trilogy 8464 · Edexcel 1SC0 · OCR Gateway J250)
Statements are paraphrased from the shared DfE combined science subject content and grouped by tier. Foundation content is studied by every student; Higher statements are examined on Higher-tier papers only. This chapter covers only what Combined Science (double award) examines — separate-science extras live on the GCSE Biology, Chemistry and Physics hubs. QuizQuip is not affiliated with AQA, Pearson Edexcel or OCR.
Foundation — every student
- 22.1List the main energy resources: fossil fuels (coal, oil, gas), nuclear fuel, biofuel, wind, hydroelectricity, geothermal, the tides, the Sun and water waves.
- 22.2Describe how energy resources are used — generating electricity, heating, cooking and transport — and which resources dominate each use.
- 22.3Distinguish renewable resources, which are replenished as they are used, from non-renewable resources, which are consumed faster than they form.
- 22.4Describe the environmental issues of each resource: landscape and wildlife damage, noise, carbon dioxide and other emissions, and the decommissioning of power stations.
- 22.5Explain why some resources are more reliable than others: some generate whatever the weather or time of day, while others depend on sunshine, wind or rainfall.
- 22.6Describe trends in the use of energy resources, including the historic dependence on (and decline of) fossil fuels and the growth of renewables in the UK energy mix.
- 22.7Calculate domestic energy use and cost in kilowatt-hours: energy transferred (kWh) = power (kW) × time (h), and cost = number of kWh × price per kWh, knowing 1 kWh = 3.6 MJ.
- 22.8Evaluate the use of different energy resources for a given purpose, weighing reliability, environmental effects, cost and scale — and explain why variable renewables still need reliable backup or storage.
Key points
- 1The resources: coal, oil, gas (fossil fuels), nuclear fuel, biofuel, wind, hydroelectricity, geothermal, tides, sunlight, water waves.
- 2Renewable = replenished as used (wind, solar, hydro, tides, biofuel, geothermal). Non-renewable = used faster than formed (coal, oil, gas, uranium).
- 3Uses: oil still rules transport; gas dominates heating and tops up electricity; electricity can come from almost anything.
- 4Environmental issues: mining and drilling scars, CO₂ and acid-rain gases, noise and eyesore objections, flooded valleys (hydro), long-lived radioactive waste and costly decommissioning (nuclear).
- 5Reliability: nuclear, gas and geothermal run whatever the weather; wind, solar and hydro dip when nature does — so grids keep reliable backup and storage (e.g. pumped hydro).
- 6UK mix: coal has collapsed since the 2000s; renewables have grown fast as costs fell and policy pushed them.
- 7Kilowatt-hours: energy (kWh) = power (kW) × time (h); 1 kWh = 3.6 MJ; cost = kWh × price per kWh. A 2.4 kW oven for 3 h = 7.2 kWh.
Notes · 1 of 4
The resources, and where each one works
Ten resources, four jobs, one sorting rule: does it refill?
Earth's energy menu: fossil fuels (coal, oil, gas), nuclear fuel (uranium), biofuel (recently living matter), and the renewable flows — wind, hydroelectricity, geothermal heat, the tides, sunlight and water waves. The sorting rule is time: a renewable resource is replenished as fast as we use it; a non-renewable one is consumed far faster than it forms, so its account only shrinks.
Each resource has its home turf. Transport still leans overwhelmingly on oil-based fuels (petrol, diesel, kerosene), with electricity entering via battery vehicles. Heating leans on gas, with some oil, biomass and heat pumps. Cooking uses gas or electricity. Electricity generation accepts almost anything — which is why the generation mix, not total energy, is where the renewable revolution shows first.
| Resource | Renewable? | Headline issue |
|---|---|---|
| Coal, oil, gas | No | CO₂, acid-rain gases, mining/drilling damage |
| Nuclear (uranium) | No | Radioactive waste; costly decommissioning |
| Biofuel | Yes | Land use competes with food; still emits when burned |
| Wind, solar | Yes | Intermittent; landscape/noise objections |
| Hydro, tidal | Yes | Flooded valleys / estuary habitats |
| Geothermal | Yes | Only practical in suitable locations |
Notes · 2 of 4
Reliability, storage and the grid
Why a calm, dull February still needs a power station.
A reliable resource generates whatever the weather or clock says: nuclear runs for months at a stretch, gas stations fire up on demand, geothermal never notices a cloud. Wind needs wind, solar needs daylight, hydro needs filled reservoirs. Demand, meanwhile, peaks predictably at breakfast and teatime — regardless of the weather.
Grids bridge the gap two ways. Backup: keep reliable stations (gas, nuclear) running or ready to cover still, dark, peak-demand hours. Storage: soak up surplus generation and give it back later — the star example is pumped-storage hydroelectricity, where spare electricity pumps water uphill into a reservoir, and demand spikes let it fall through turbines again. The round trip is worthwhile because generation and demand rarely match naturally.
Worked example — pumped-storage energy
Q: A pumped-storage station’s upper reservoir holds 5.0 × 10⁶ kg of water 40 m above its turbines (g = 9.8 N/kg). Find the gravitational energy available, in joules and kWh, and the recoverable amount if the station is 80% efficient. A: Ep = mgh = 5.0 × 10⁶ × 9.8 × 40 = 1.96 × 10⁹ J. Divide by 3.6 × 10⁶ J per kWh: 1.96 × 10⁹ ÷ 3.6 × 10⁶ ≈ 544 kWh. At 80% efficiency the grid gets back 0.80 × 544 ≈ 436 kWh.
Notes · 3 of 4
The UK energy mix
Coal's collapse, renewables' climb — and why the mix keeps shifting.
Two centuries of coal, then North Sea oil and gas, built the modern UK energy system — and its emissions. Since the 2000s the mix has turned: coal has collapsed from the majority fuel to almost nothing, gas carries the balancing load, nuclear holds a steady share, and renewables — wind above all — have grown from a rounding error to a major supplier as turbine and panel costs fell and policy pushed them in.
Why the mix keeps changing: cost (renewables got cheap), policy (emissions targets), technology (bigger turbines, cheaper batteries) and public pressure on air quality and climate. Exam answers should describe the trend (fossil share falling, renewable share rising, total demand roughly steady), then attach reasons — that pairing earns the marks.
Worked example — describing a trend safely
Q: Describe how the UK's electricity mix has changed since 2010 and give two reasons. A: Trend: the fossil-fuel share (especially coal) has fallen while the renewable share (especially wind and solar) has risen. Reasons: renewable generation costs fell, making wind and solar competitive; and government targets on carbon emissions pushed coal off the system. State the direction, name the resources, then justify — in that order.
Notes · 4 of 4
Kilowatt-hours and the electricity bill
The unit your meter counts — and the arithmetic behind every bill.
Homes are billed in kilowatt-hours (kWh) — "units" — not joules, because joule numbers would be absurdly large. One kWh is the energy a 1 kW appliance transfers in 1 hour: energy (kWh) = power (kW) × time (h). In joules, 1 kWh = 3.6 × 10⁶ J (1000 W × 3600 s). The bill is simply cost = kWh × price per kWh.
Exam tips
- Worked example — pricing an oven. Q: A 2.4 kW oven roasts for 3.0 h; electricity costs 30 p per kWh. Find the energy used and the cost. A: Energy = 2.4 × 3.0 = 7.2 kWh. Cost = 7.2 × 30 p = 216 p = £2.16. Keep power in kW (not W) and time in hours (not minutes) and the arithmetic stays clean.
- Worked example — a year of fridge. Q: A 0.50 kW fridge runs around the clock. Find its yearly energy and cost at 30 p/kWh. A: Hours per year: 24 × 365 = 8760 h. Energy = 0.50 × 8760 = 4380 kWh. Cost = 4380 × 30 p = £1314. Multiply the per-day (or per-hour) figure up to a year before pricing — most mistakes here are time-conversion slips.
Revise
Key terms
The words examiners expect you to use precisely.
- Renewable resource
- An energy resource replenished as fast as it is used — wind, solar, hydro, tidal, biofuel, geothermal.
- Non-renewable resource
- A resource consumed faster than it forms — coal, oil, gas and uranium.
- Reliable resource
- One that generates whatever the weather or time of day, such as nuclear, gas or geothermal.
- Pumped-storage hydroelectricity
- Storage that uses spare electricity to pump water uphill, releasing it through turbines when demand peaks.
- Kilowatt-hour (kWh)
- The energy transferred by a 1 kW appliance in 1 hour; equal to 3.6 MJ — the "unit" on electricity bills.
- Decommissioning
- The safe shutdown and dismantling of a power station at the end of its life — a major cost for nuclear plants.
Show 2 more key termsShow fewer key terms
- Energy mix
- The combination of resources a country draws on, e.g. gas, wind, nuclear and imports.
- Biofuel
- A fuel made from recently living material; renewable because the source can be regrown, though burning it still releases CO₂.
Revise
Common mistakes
Where students most often lose marks in this chapter — and what to do instead.
Mistake: Calling nuclear power renewable
Uranium ore is mined and finite, like coal.
Instead: Nuclear is reliable and low-carbon, but non-renewable — the fuel runs out faster than Earth replaces it.
Mistake: Calling biofuel automatically clean
Burning it still releases carbon dioxide and needs farmland.
Instead: Biofuel is renewable (it regrows) but not emission-free, and it competes with food for land.
Show 10 more mistakesShow fewer mistakes
Mistake: Mixing kW and kWh
One is a rate, the other an amount of energy.
Instead: kW is power; kWh is power × time. Bills count kWh.
Mistake: Forgetting 1 kWh = 3.6 MJ
Conversions between kWh and joules go wildly wrong.
Instead: 1000 W × 3600 s = 3.6 × 10⁶ J per kWh.
Mistake: Dividing by 60 twice when converting minutes to hours
Minutes to hours is one division.
Instead: 10 min = 10/60 h ≈ 0.167 h; then multiply by the kW rating.
Mistake: Saying wind power is useless because wind stops
Intermittent does not mean useless.
Instead: Wind is a cheap, clean, large-scale resource — its output just varies, so grids add backup and storage.
Mistake: Claiming hydroelectric dams release no environmental damage
Flooding valleys destroys habitats and displaces people.
Instead: Hydro is renewable and low-carbon but its reservoirs flood land and alter rivers.
Mistake: Forgetting decommissioning in nuclear evaluations
The end-of-life cost is a real disadvantage.
Instead: Nuclear needs long-lived waste storage and expensive, slow decommissioning.
Mistake: Reading a bill in "units" as joules
Suppliers bill in kWh.
Instead: Multiply kWh by the price per kWh; never convert bills to joules.
Mistake: Confusing acid-rain gas with greenhouse gas
They are different problems from different gases.
Instead: SO₂ and NOx cause acid rain; CO₂ and methane drive global warming. Coal produces both kinds.
Mistake: Saying the UK still generates most electricity from coal
That was decades ago.
Instead: Coal has nearly vanished from the UK mix; gas, wind and nuclear dominate today.
Mistake: Quoting tidal power as weather-dependent
Tides follow the Moon, not the clouds.
Instead: Tides are perfectly predictable but intermittent — they generate in scheduled bursts, not on demand.
Check yourself
Quick quiz
20 questions with instant explanations. About 5 minutes.
Question 1 of 3· free preview of 20
- Question 1: current question
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- Question 3: not answered
Describe energy resources and where each works
Which of these is a non-renewable resource?
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Practise
Topical questions
12 exam-style questions with model answers and mark schemes.
A set of structured and calculation questions matched to this chapter, in three tiers, each with a model answer, mark scheme and examiner tip. Higher-tier questions are tagged.
Practise topical questionsExam practice
Practice paper
A 30-mark paper in the style of a Combined Science paper, with a separate mark scheme. Give yourself 40 min.
Question paper
Chapter 22 Practice Paper
30 marks · 40 min · 5 pages
6 multiple-choice questions and structured questions with answer lines. Renewable and non-renewable resources, uses of energy resources, environmental impacts, reliability and grid backup/storage, UK energy mix trends, and kilowatt-hour energy and cost calculations.
Mark scheme
PROChapter 22 Practice Paper — mark scheme
Answers · Marking points · 3 pages
Model answers with a mark for each creditworthy point — for marking at home or in class.
How does this chapter fit the real exams?
Physics Paper 1
1 h 15 · 70 marks (Trilogy)
Energy, electricity, particle model, atomic structure (chapters 21–26)
Physics Paper 2
1 h 15 · 70 marks (Trilogy)
Forces, waves, magnetism and electromagnetism (chapters 27–30)
Tiers
Foundation (grades 1-1 to 5-5) · Higher (4-3 to 9-9)
Two grades are awarded together; the 21 required practicals are examined on the written papers
Want a full paper? Try the Biology Paper 1-style (Foundation), Biology Paper 1-style (Higher), Biology Paper 2-style (Foundation), Biology Paper 2-style (Higher), Chemistry Paper 1-style (Foundation), Chemistry Paper 1-style (Higher), Chemistry Paper 2-style (Foundation), Chemistry Paper 2-style (Higher), Physics Paper 1-style (Foundation), Physics Paper 1-style (Higher), Physics Paper 2-style (Foundation), Physics Paper 2-style (Higher), Required practicals practice sets.
Questions
Frequently asked questions
Is nuclear power renewable?
No. It is reliable and low-carbon, but its uranium fuel is mined from finite ores — used far faster than it forms — so it counts as non-renewable.
How do I avoid kW/kWh mistakes in cost questions?
Convert power to kW and time to hours before multiplying. 10 minutes is 10/60 of an hour, not 10. Then cost = kWh × price per kWh — pence times units.
What is the difference between acid rain and global warming gases?
Sulfur dioxide and nitrogen oxides make acid rain; carbon dioxide and methane warm the planet. Coal conveniently produces both, which is why evaluations must not mix them up.
Why keep gas stations if wind is cheaper?
Because the wind does not keep appointments. Grids need resources that generate on demand — gas, nuclear, geothermal — plus storage such as pumped hydro, to cover still, dark, high-demand periods.
How do I answer an energy-resource evaluation question?
Pick a resource per side, then weigh at least two categories: reliability, environmental impact, cost, scale, waste. State the trade-off and finish with a justified conclusion — "best for this purpose because…".
Up next
Chapter 23: Electric circuits