# Energy Resources — GCSE Physics
The world needs vast amounts of energy for electricity, transport, and heating. Understanding the different energy resources — their advantages, disadvantages, and environmental impacts — is crucial for making informed decisions about our energy future.
1. Non-Renewable Energy Resources
Non-renewable resources will eventually run out. They cannot be replenished within a human lifetime.
1.1 Fossil Fuels (Coal, Oil, Natural Gas)
How they work: Burned to heat water → steam → turns turbines → generates electricity.
| Advantages | Disadvantages |
|---|---|
| Reliable — can generate any time | Release CO₂ (greenhouse gas → climate change) |
| High energy density | Release SO₂ and NOₓ (acid rain) |
| Existing infrastructure | Finite — will run out |
| Relatively cheap (currently) | Mining/drilling damages habitats |
| Can adjust output to meet demand | Air pollution affects health |
1.2 Nuclear Power
How it works: Nuclear fission of uranium/plutonium → heat → steam → turbines → electricity.
| Advantages | Disadvantages |
|---|---|
| No greenhouse gases during operation | Produces radioactive waste (dangerous for thousands of years) |
| Very high energy density | Risk of nuclear accidents (e.g., Chernobyl, Fukushima) |
| Reliable (runs 24/7) | Very expensive to build and decommission |
| Small amount of fuel needed | Uranium is non-renewable |
| Long operational life | Long planning and building time |
2. Renewable Energy Resources
Renewable resources are replenished naturally and will not run out.
2.1 Wind Power
How it works: Wind turns blades of a turbine → generator → electricity.
| Advantages | Disadvantages |
|---|---|
| No greenhouse gases | Intermittent (no wind = no electricity) |
| Free fuel | Visual/noise pollution |
| Low running costs | Needs many turbines for significant output |
| Can be placed offshore | Can harm birds |
2.2 Solar Power
How it works: Solar cells (photovoltaic) convert sunlight directly to electricity. Solar thermal panels heat water.
| Advantages | Disadvantages |
|---|---|
| No greenhouse gases | Only works during daylight (intermittent) |
| Free fuel (sunlight) | Less effective in cloudy/northern climates |
| Low maintenance | Large area needed |
| Can be placed on existing buildings | Manufacturing has some environmental cost |
2.3 Hydroelectric Power
How it works: Water stored behind a dam is released → flows downhill → turns turbines → electricity.
| Advantages | Disadvantages |
|---|---|
| Reliable and controllable | Flooding large areas destroys habitats |
| No greenhouse gases (in operation) | Expensive to build |
| Can respond quickly to demand | Limited suitable locations |
| Long lifespan | Disrupts river ecosystems |
2.4 Tidal Power
How it works: Rising and falling tides drive turbines (tidal barrages or tidal stream generators).
| Advantages | Disadvantages |
|---|---|
| Predictable (tides are regular) | Very expensive to build |
| No greenhouse gases | Few suitable locations |
| Reliable | Can affect marine ecosystems |
| Only generates at certain tide times |
2.5 Wave Power
How it works: Wave motion drives floating generators on the sea surface.
| Advantages | Disadvantages |
|---|---|
| No greenhouse gases | Unreliable (weather-dependent) |
| Free fuel | Difficult to maintain at sea |
| Small-scale output currently |
2.6 Geothermal Energy
How it works: Hot rocks underground heat water → steam → turbines → electricity. Or direct heating.
| Advantages | Disadvantages |
|---|---|
| Very reliable (24/7) | Very few suitable locations |
| No greenhouse gases | Expensive to drill deep wells |
| Free fuel | Can release some gases from underground |
| Small land footprint |
2.7 Biomass (Bio-energy)
How it works: Organic material (wood, crops, waste) is burned or fermented to produce energy.
| Advantages | Disadvantages |
|---|---|
| Carbon neutral (in theory) | Burning still releases CO₂ and particulates |
| Uses waste materials | Requires large areas of land to grow |
| Reliable | Can compete with food production |
3. Comparison Table
| Resource | Renewable? | Reliable? | Environmental Impact |
|---|---|---|---|
| Coal | No | Yes | High (CO₂, SO₂) |
| Oil | No | Yes | High (CO₂, spills) |
| Gas | No | Yes | Medium (CO₂, less than coal) |
| Nuclear | No | Yes | Low CO₂, radioactive waste |
| Wind | Yes | No (intermittent) | Low (visual impact) |
| Solar | Yes | No (intermittent) | Low |
| Hydroelectric | Yes | Yes | Habitat destruction |
| Tidal | Yes | Mostly | Marine ecosystem impact |
| Geothermal | Yes | Yes | Very low |
| Biomass | Yes | Yes | Medium (CO₂, land use) |
4. Trends in Energy Use
- Global energy demand is increasing (population growth, development)
- Moving towards renewable sources to combat climate change
- Energy security — countries want diverse energy supplies
- Energy storage (batteries) is key for intermittent renewables
- Carbon capture technology may allow continued fossil fuel use with reduced emissions
Worked Example: Example 1
Question: Give two advantages and two disadvantages of using wind power to generate electricity.
Answer: Advantages: (1) No greenhouse gases produced during operation. (2) Wind is free and renewable, so it will not run out. Disadvantages: (1) Wind is intermittent — if there's no wind, no electricity is generated. (2) Wind turbines can cause visual and noise pollution.
Worked Example: Example 2
Question: Explain why nuclear power is sometimes considered a solution to climate change despite its disadvantages.
Answer: Nuclear power stations produce no greenhouse gases during operation (unlike fossil fuels). They can generate large amounts of electricity reliably (unlike wind and solar). However, they produce dangerous radioactive waste, are expensive to build and decommission, and carry a small risk of catastrophic accidents.
6. Practice Questions
- Define "renewable" and "non-renewable" energy resources. Give one example of each. (4 marks)
- Compare the environmental impacts of a coal-fired power station and a wind farm. (4 marks)
- Explain why solar panels alone cannot reliably meet a country's electricity demand. (3 marks)
- A government wants to reduce carbon emissions but maintain a reliable electricity supply. Suggest an energy strategy and explain your reasoning. (6 marks)
Answers
- Renewable: A resource that is replenished naturally and will not run out (e.g., solar). Non-renewable: A resource that will eventually be used up and cannot be replaced (e.g., coal).
Want to check your answers and get step-by-step solutions?
Summary
- Non-renewable: coal, oil, gas, nuclear — reliable but finite and/or polluting
- Renewable: wind, solar, hydro, tidal, wave, geothermal, biomass — sustainable but some are intermittent
- Key trade-offs: reliability vs. environmental impact, cost vs. carbon emissions
- A mixed energy strategy provides security and reduces emissions
- Energy storage is crucial for a renewable future