Energy Resources

This lesson covers the different energy resources used to generate electricity and heat, as required by the Edexcel GCSE Physics specification (1PH0), Topic 3: Conservation of Energy. You need to know the difference between renewable and non-renewable resources, their advantages and disadvantages, and their environmental impacts.

---

Renewable vs Non-Renewable

Energy resources are classified into two groups:

Type	Definition	Examples
Non-renewable	Resources that will eventually run out — they are being used faster than they can be replaced	Fossil fuels (coal, oil, natural gas), nuclear fuel (uranium)
Renewable	Resources that will not run out — they are replenished naturally within a human lifetime	Solar, wind, hydroelectric, tidal, wave, geothermal, biomass

Exam Tip: Nuclear fuel (uranium) is classified as non-renewable because there is a finite supply of uranium ore. Do not confuse nuclear with renewable — this is a very common mistake.

---

Non-Renewable Energy Resources

Fossil Fuels (Coal, Oil, Natural Gas)

• Formed over millions of years from the remains of dead organisms.
• Burned to release thermal energy, which heats water to produce steam.
• Steam turns turbines, which drive generators to produce electricity.
• Currently provide the majority of the UK's energy.

Fuel	Main Uses
Coal	Power stations, some industrial processes
Oil	Transport (petrol, diesel), power stations, heating
Natural gas	Domestic heating, cooking, power stations

Advantages:

• Reliable — can generate electricity at any time, regardless of weather.
• Relatively cheap (currently) and well-established infrastructure.
• Can produce large amounts of electricity.
• Can respond to changes in demand (especially gas power stations).

Disadvantages:

• Burning fossil fuels releases CO₂, contributing to climate change (global warming).
• Produces sulfur dioxide (acid rain) and particulates (air pollution, health problems).
• They will eventually run out — they are finite.
• Oil spills can cause environmental damage.
• Mining coal causes habitat destruction and landscape scarring.

Nuclear Fuel

• Nuclear fission of uranium (or plutonium) releases large amounts of thermal energy.
• This heats water to produce steam → turbines → generators → electricity.

Advantages:

• Produces no CO₂ during operation (no contribution to climate change from the generation process).
• Very reliable — not dependent on weather.
• Produces a large amount of energy from a small amount of fuel.
• Fuel supplies will last longer than fossil fuels.

Disadvantages:

• Produces radioactive waste that remains hazardous for thousands of years — difficult and expensive to store safely.
• Risk of nuclear accidents (e.g., Chernobyl, Fukushima).
• Very expensive to build and decommission nuclear power stations.
• Not truly "clean" — mining uranium produces CO₂, and so does construction.
• Long start-up time — cannot respond quickly to changes in demand.

---

Renewable Energy Resources

Solar Energy

• Solar panels (photovoltaic cells) convert sunlight directly into electricity.
• Solar thermal panels use sunlight to heat water.

Advantage	Disadvantage
No CO₂ emissions during operation	Depends on sunlight — does not work at night or in cloudy weather
No fuel costs — sunlight is free	High initial cost to install
Low maintenance	Large area of panels needed for significant output
Can be installed on rooftops (no extra land)	Energy output varies with seasons (less in winter)

Wind Energy

• Wind turbines convert the kinetic energy of the wind into electricity via a generator.

Advantage	Disadvantage
No CO₂ emissions during operation	Unreliable — wind does not blow constantly
No fuel costs	Visual pollution — some people find them unsightly
Can be placed offshore (out of sight, stronger winds)	Noise pollution from rotating blades
Low running costs	Can harm birds and bats
	Require a large number for significant output

Hydroelectric Energy

• Water stored behind a dam falls through pipes, turning turbines that drive generators.

Advantage	Disadvantage
No CO₂ during operation	Flooding valleys destroys habitats and displaces communities
Very reliable — water can be released on demand	High initial cost of building the dam
Can respond quickly to demand (start/stop rapidly)	Limited suitable locations (need a valley and river)
Long lifespan	Can affect river ecosystems downstream

Tidal Energy

• Uses the rise and fall of tides to turn turbines in a tidal barrage or tidal stream generator.

Advantage	Disadvantage
No CO₂ during operation	Very high initial cost
Highly predictable — tides are reliable	Limited suitable locations (need large tidal range)
	Disrupts marine habitats and ecosystems
	Only generates for part of the day (tides are periodic)

Wave Energy

• Floating devices on the sea surface capture the kinetic energy of waves and convert it to electricity.

Advantage	Disadvantage
No CO₂ during operation	Unreliable — wave strength varies
No fuel costs	Expensive to build and maintain
	Can be damaged by storms
	Low power output compared to other sources
	Visual impact on coastline

Geothermal Energy

• Uses heat from deep underground (from radioactive decay in the Earth's core) to heat water and produce steam.

Advantage	Disadvantage
No CO₂ during operation (minimal)	Very few suitable locations (need volcanic/tectonic areas)
Very reliable — heat is always available	High initial drilling costs
No fuel costs	Not widely available in the UK
Low running costs

Biomass

• Organic materials (wood, crops, animal waste) are burned or fermented to release energy.

Advantage	Disadvantage
Carbon neutral in theory (CO₂ absorbed during growth = CO₂ released when burned)	Releases CO₂ and particulates when burned
Reliable — can burn fuel on demand	Requires large areas of land to grow fuel crops
Uses waste materials	Can lead to deforestation if not managed sustainably
Can be used in existing power stations	Not truly carbon neutral when transport/processing is included

Exam Tip: Biomass is described as "carbon neutral" because the CO₂ released when it is burned was absorbed from the atmosphere when the plants grew. However, this is only true if new plants are grown to replace those used, and it ignores the CO₂ produced during transport and processing.

---

The UK Energy Mix

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

• The proportion of energy from coal has decreased significantly.
• The proportion from natural gas has increased.
• The proportion from renewables (especially wind and solar) is increasing rapidly.
• Nuclear provides a roughly constant proportion.

Why the UK Needs a Mix of Resources