Energy Resources

This lesson covers energy resources, including the differences between renewable and non-renewable sources, as required by the Edexcel GCSE Combined Science specification (1SC0). You need to know the advantages and disadvantages of each resource and how they are used to generate electricity.

Energy Resources and Electricity Generation

Most of the electricity we use is generated in power stations. The basic process for many power stations is:

A fuel is burned (or a nuclear reaction occurs) to heat water.
The water produces steam.
The steam turns a turbine.
The turbine drives a generator.
The generator produces electricity.

flowchart LR
    A["Fuel\n(chemical/nuclear store)"] -->|Heating| B["Water → Steam"]
    B -->|Mechanically| C["Turbine"]
    C -->|Mechanically| D["Generator"]
    D -->|Electrically| E["National Grid"]

Exam Tip: Learn this sequence: fuel → steam → turbine → generator → electricity. Many exam questions ask you to describe how a particular resource generates electricity.

Non-Renewable Energy Resources

Non-renewable resources will eventually run out because they are being used faster than they are being formed. They took millions of years to form.

Resource	Energy store	How it generates electricity
Coal	Chemical	Burned to heat water → steam → turbine → generator
Oil	Chemical	Burned to heat water → steam → turbine → generator
Natural gas	Chemical	Burned to heat water → steam → turbine → generator
Nuclear fuel (uranium/plutonium)	Nuclear	Nuclear fission heats water → steam → turbine → generator

Advantages of Non-Renewable Resources

Reliable — can generate electricity at any time (not weather-dependent).
High power output — a single power station can supply a large city.
Existing infrastructure — power stations and supply chains are already built.
Relatively cheap (at present) per unit of energy.

Disadvantages of Non-Renewable Resources

Finite — they will run out.
Produce CO₂ when burned (fossil fuels), contributing to climate change and global warming.
Coal and oil release sulfur dioxide (SO₂), causing acid rain.
Burning fossil fuels produces particulates, harming health.
Nuclear fuel produces radioactive waste that must be stored safely for thousands of years.
Oil spills and coal mining cause environmental damage.

Renewable Energy Resources

Renewable resources will not run out because they are replenished naturally on a short timescale.

Resource	Energy source	How it generates electricity
Solar	Radiation from the Sun	Photovoltaic cells convert light directly into electricity
Wind	Kinetic energy of air	Wind turns turbine blades → generator
Hydroelectric	GPE of water	Falling water turns turbines → generator
Tidal	Kinetic energy of tides	Moving water turns turbines → generator
Wave	Kinetic energy of waves	Bobbing motion drives generators
Geothermal	Thermal energy from Earth's interior	Hot rocks heat water → steam → turbine → generator
Bio-fuel	Chemical energy from organic matter	Burned to heat water → steam → turbine → generator

Exam Tip: Bio-fuel is considered renewable because new crops can be grown to replace what is burned. However, burning bio-fuel still releases CO₂ — it is carbon neutral only if the CO₂ absorbed during growth equals the CO₂ released when burned.

Comparison Table

Factor	Fossil Fuels	Nuclear	Solar	Wind	Hydroelectric
Renewable?	No	No	Yes	Yes	Yes
Reliable?	Yes	Yes	No (daylight only)	No (wind dependent)	Yes
CO₂ emissions	High	Very low	None	None	None
Other pollution	SO₂, particulates	Radioactive waste	None	Visual, noise	Habitat flooding
Start-up time	Moderate	Slow	Instant	Instant	Fast
Power output	Very high	Very high	Low per panel	Low per turbine	High
Land use	Moderate	Small	Large (solar farms)	Large (wind farms)	Large (reservoirs)

Using Energy Resources

Energy resources are used for more than just electricity:

Use	Examples of resources
Transport	Petrol, diesel (oil), bio-fuel, electricity (from any source)
Heating	Natural gas, oil, geothermal, solar thermal, bio-fuel
Electricity generation	All of the resources listed above

The Energy Mix

The energy mix is the combination of energy resources used by a country. The UK's energy mix is changing:

Decreasing use of coal (due to emissions and policy).
Increasing use of wind and solar (due to climate targets).
Natural gas remains a major source but is being gradually reduced.
Nuclear provides a steady base load.

Why the Mix Is Changing

Driver	Effect
Climate change	Shift away from fossil fuels to reduce CO₂
Government policy	Subsidies for renewables; carbon taxes
Technology	Falling costs of solar panels and wind turbines
Energy security	Reducing dependence on imported fuels
Public opinion	Support for cleaner energy

Exam Tip: Exam questions often ask you to evaluate whether a particular energy resource is suitable for a given location or scenario. Consider reliability, environmental impact, cost and power output in your answer.

Environmental Impacts

Impact	Resources involved
Climate change (CO₂)	Coal, oil, natural gas
Acid rain (SO₂)	Coal, oil
Radioactive waste	Nuclear
Habitat destruction	Hydroelectric (flooding), wind (birds), bio-fuel (deforestation)
Visual pollution	Wind turbines, solar farms
Noise pollution	Wind turbines

Summary

Non-renewable resources (coal, oil, natural gas, nuclear) will eventually run out.
Renewable resources (solar, wind, hydroelectric, tidal, wave, geothermal, bio-fuel) are replenished naturally.
Most power stations use the sequence: fuel → steam → turbine → generator.
Fossil fuels produce CO₂ (climate change) and other pollutants.
Nuclear power produces radioactive waste but very low CO₂ emissions.
Renewable resources have lower environmental impact but can be unreliable (weather-dependent) and have lower power output.
The UK's energy mix is shifting towards more renewable sources.
When evaluating resources, consider: reliability, cost, environmental impact, power output and location.

Energy Resources

Energy Resources