Energy ResourcesAQA GCSE Physics: Revision notes

Section 1

What are renewable and non-renewable energy resources?

Energy resources are sources of energy that can be used to generate electricity or produce direct heating.

Renewable energy resources are naturally replenished and will not run out within a human timescale. They are continuously available from natural processes.

Non-renewable energy resources are finite and will eventually run out. Once used, they take millions of years to form again.

Resource Type	Examples	Key Feature
Renewable	Wind, solar, water (waves, tidal, hydroelectric), geothermal, bio-fuel	Continuous supply, naturally replenished
Non-renewable	Fossil fuels (coal, oil, natural gas), nuclear	Limited supply, will deplete

Fossil fuels and nuclear energy are non-renewable, while wind, water (including waves, tidal, and hydroelectric), solar, geothermal, and bio-fuel are renewable.

Key termsrenewable energy resourcesnon-renewable energy resourcesenergy resources

Exam tip

Examiners expect you to clearly categorise each resource as either renewable or non-renewable. Always justify your answer by explaining whether the resource is naturally replenished or finite.

Think of it like this

Think of renewable resources like a rechargeable battery that tops itself up automatically, while non-renewable resources are like a one-time-use battery that eventually goes flat.

Section 2

How do fossil fuels and nuclear energy generate electricity?

Fossil fuels (coal, oil, natural gas) and nuclear energy are used to generate electricity through the same basic process:

Heat energy is released (burning fossil fuels or nuclear fission)
This heat boils water to produce steam
The steam drives a turbine, converting thermal energy to kinetic energy
The turbine drives a generator, which converts kinetic energy to electrical energy

Fossil fuels release energy through combustion (burning), releasing carbon dioxide and other pollutants.

Nuclear energy releases energy through nuclear fission (splitting heavy nuclei), producing no carbon dioxide but radioactive waste.

Both methods use a thermal power station design but differ in their heat source and waste products.

Key termsfossil fuelsnuclear energycombustionnuclear fissionthermal power station

Exam tip

When describing electricity generation, always follow the energy chain: heat energy → steam → turbine (kinetic energy) → generator → electrical energy. This shows the examiner you understand the complete process.

Common mistake

Students often say nuclear power produces electricity directly. It doesn't—nuclear fission produces heat, which boils water into steam, which drives a turbine. The energy conversion is the same as fossil fuels.

Section 3

How do renewable sources generate electricity and heat?

Wind energy: Wind turbines have blades that rotate in wind, directly driving a generator to produce electricity. No heat stage required.

Solar energy:

Photovoltaic cells convert sunlight directly into electrical energy
Solar thermal panels absorb sunlight to heat water directly for heating purposes

Water-based energy:

Hydroelectric power: Water stored behind a dam falls through a height, driving turbines connected to generators. The gravitational potential energy of water is converted to kinetic energy, then electrical energy.
Tidal energy: Tides cause water to flow through turbines, generating electricity. Uses predictable tidal movements.
Wave energy: Waves cause oscillating motion that drives turbines or pumps to generate electricity.

Geothermal energy: Hot rocks beneath the Earth's surface heat water, creating steam that drives turbines. Can also heat buildings directly without electricity generation.

Bio-fuel: Organic material (wood, crop waste, animal waste) is burned like fossil fuels to release heat energy, either for direct heating or driving turbines for electricity. The carbon released is reabsorbed by new plant growth, making it lower-carbon.

Renewable sources have varied conversion pathways—some produce heat directly, others electricity, and some can do both.

Key termswind energysolar energyphotovoltaic cellshydroelectric powertidal energywave energygeothermal energybio-fuel

Exam tip

For each renewable source, identify whether it produces electricity, heat, or both. Examiners test this distinction—solar thermal produces heat directly, while photovoltaic produces electricity.

Example

Hydroelectric: Water at height has gravitational potential energy (mgh). As it falls, this converts to kinetic energy (½mv²). The moving water spins a turbine, converting kinetic energy to rotational motion, which drives a generator to produce electrical energy.

Section 4

What are the environmental, economic, and social impacts of energy resources?

Environmental impacts:

Resource	Advantages	Disadvantages
Fossil fuels	Reliable, established infrastructure	Greenhouse gases (CO₂), air pollution, climate change, habitat destruction (mining)
Nuclear	No greenhouse gases, low land use	Radioactive waste (long-term storage problem), risk of accidents, uranium mining
Wind	Renewable, low operating costs, no emissions	Visual impact, noise, bird/bat deaths, variable output
Solar	Renewable, silent, no emissions	Land use, manufacturing impact, variable output (weather/season)
Hydroelectric	Renewable, no emissions, flood control	Habitat destruction, dam failure risk, methane from reservoirs
Tidal	Renewable, predictable, no emissions	Marine ecosystem impact, high installation cost
Wave	Renewable, no emissions	Unpredictable, high installation cost, marine impact
Geothermal	Renewable, reliable, low emissions	Limited locations, induced seismic activity (rare)
Bio-fuel	Renewable, carbon-neutral (in theory)	Land use competes with food production, deforestation

Economic impacts:

Fossil fuels: Low initial cost but vulnerable to price volatility; health and environmental costs not included in price
Nuclear: High upfront capital costs, long-term waste disposal costs
Renewables: Varying initial costs; wind and solar becoming cheaper; provides long-term energy independence
Employment: Fossil fuels employ fewer people per unit energy; renewables create more jobs

Social impacts:

Energy security: Reliance on imported fossil fuels vs. local renewable resources
Health: Air pollution from fossil fuels causes respiratory disease; nuclear waste concerns
Fairness: Communities near mining, dams, or wind farms may bear disproportionate impacts
Access: Energy poverty in developing nations; renewable energy can provide distributed power

Key termsenvironmental impacteconomic impactsocial impactgreenhouse gasesradioactive waste

Exam tip

Examiners want balanced evaluation—acknowledge both advantages and disadvantages for each resource. Use phrases like 'although... there is a concern that...' to show critical thinking. Avoid simply listing impacts; explain why each matters.

Common mistake

Students often claim renewable energy has zero impact. While cleaner than fossils, renewables have real environmental costs: solar requires rare earth mining, hydroelectric destroys habitats, and wind kills birds. Acknowledge trade-offs.

Section 5

Why are patterns of energy resource use changing in the UK and globally?

Reasons for changing patterns:

Climate change concerns: Rising CO₂ levels from burning fossil fuels drive policy shift toward low-carbon renewables. The Paris Agreement (2015) committed nations to reduce emissions.
Renewable technology improvements: Cost of wind and solar has fallen dramatically (70% drop in last decade). Battery storage improving makes renewables more practical.
Resource depletion: Fossil fuels are finite; peak oil concerns have driven diversification.
Energy security: Reliance on imported oil/gas makes countries vulnerable to price shocks and geopolitical conflict. Domestic renewables increase independence.
Government policy and subsidies: Feed-in tariffs, carbon taxes, and renewable energy targets incentivise renewable investment. EU requires 32% renewable energy by 2030.
Energy demand changes: Growing electricity use (especially in developing nations) and efficiency improvements change consumption patterns.
Public pressure: Increased awareness of climate change and air pollution drives political and consumer demand for clean energy.

UK-specific trends:

Coal use has declined sharply (from 30% of electricity in 2015 to <2% by 2023)
Wind energy now provides ~30% of UK electricity
Nuclear remaining stable at ~20% of electricity
Gas still significant (~40%) but declining
Solar and other renewables growing rapidly

Global trends:

China leading renewable capacity investment but still coal-dependent
Developing nations increasingly adopting solar (cheaper than building grid infrastructure)
Energy poverty driving renewable solutions in remote areas
OPEC nations facing pressure to diversify away from oil

Key termsclimate changerenewable energy transitionenergy securityenergy demandenergy policy

Exam tip

When explaining changing patterns, link cause to effect: for example, 'as renewable technology costs fell (cause), investment increased (effect), leading to higher renewable capacity (result).' This shows you understand the driving forces.

Example

The UK's coal decline: Coal was 30% of electricity in 2015 → carbon taxes made coal uneconomic → renewable costs fell below coal → government promoted wind/solar → coal plants closed → by 2023 coal was <2%. Multiple factors (policy, economics, technology) work together.

Must Know

Renewable resources (wind, solar, water, geothermal, bio-fuel) are naturally replenished; non-renewable resources (fossil fuels, nuclear) are finite and will deplete.
Fossil fuels and nuclear both use thermal power stations: heat boils water → steam drives turbine → generator produces electricity. Fossil fuels emit CO₂; nuclear produces radioactive waste.
Renewable electricity generation varies by source: wind turbines rotate directly; solar photovoltaic cells convert light to electricity; hydroelectric/tidal/wave use flowing water to drive turbines; geothermal uses underground heat; bio-fuel is burned like fossil fuels.
Environmental impacts: Fossil fuels cause greenhouse gases and pollution; nuclear produces long-term radioactive waste; renewables have lower emissions but varying local impacts (land use, wildlife, visual/noise).
Economic and social factors: Renewable costs falling rapidly making them competitive; fossil fuel prices volatile; energy security concerns drive diversification; employment and health effects differ by resource.
Changing patterns driven by: Climate change awareness, falling renewable technology costs, resource depletion concerns, energy security needs, government policy/subsidies, and public pressure. UK coal collapsed; renewables (especially wind) rapidly growing globally.

That's the notes covered.

Carry on to the next subtopic.