National and Global Energy Resources
National and Global Energy Resources
The UK and the world rely on a mix of energy resources to generate electricity, heat buildings, and power transport. These resources fall into two categories: renewable and non-renewable.
Non-Renewable Energy Resources
Non-renewable resources are used up faster than they can be replaced. They will eventually run out.
| Resource | How it works | Advantages | Disadvantages |
|---|---|---|---|
| Fossil fuels (coal, oil, natural gas) | Burned to heat water; steam drives turbines connected to generators | Reliable, high power output, relatively cheap | Produce CO2 (climate change), SO2 (acid rain); finite supply |
| Nuclear fuel (uranium, plutonium) | Nuclear fission heats water; steam drives turbines | No CO2 during operation, very high energy density, reliable | Radioactive waste (difficult to dispose of safely), risk of accidents, high decommissioning costs |
Most fossil fuel and nuclear power stations work the same way:
1. Fuel heats water to produce steam
2. Steam drives a turbine
3. The turbine spins a generator
4. The generator produces electricity
Renewable Energy Resources
Renewable resources are replenished naturally and will not run out.
Wind power — Wind turns blades of a turbine connected to a generator. No pollution during operation, but output depends on wind speed (unreliable). Wind farms can be visually intrusive and noisy.
Solar power — Photovoltaic cells convert sunlight directly into electricity. No pollution, low maintenance, but only works in daylight and output varies with weather and seasons. Large areas needed for significant output.
Hydroelectric power — Water stored behind a dam is released through turbines. Very reliable and can respond quickly to demand. However, flooding valleys destroys habitats and displaces communities. High initial cost.
Tidal power — Barrages or turbines capture energy from tidal water movement. Very predictable (tides are regular), but few suitable locations, high construction cost, and impacts on estuary ecosystems.
Wave power — Floating devices on the sea surface capture kinetic energy from waves. Still largely experimental, unreliable output, and devices can be damaged by storms.
Geothermal power — Heat from radioactive decay deep underground is used to produce steam for turbines. Very reliable where available, but only practical in areas with suitable geology (e.g. volcanic regions like Iceland). Few suitable UK sites.
Biomass — Organic material (wood, crops, waste) is burned or fermented to release energy. Can be carbon-neutral if replanted, but burning still releases particulates. Land used for fuel crops could grow food.
Comparing Energy Resources
When evaluating energy resources, consider:
- Reliability — Can it produce electricity on demand? Fossil fuels and nuclear are reliable. Wind and solar are intermittent (weather-dependent).
- Environmental impact — CO2 emissions, habitat destruction, visual impact, noise, waste disposal
- Cost — Initial setup, running costs, decommissioning
- Scale — How much power can it generate? A single wind turbine produces far less than a gas power station.
The UK Energy Mix
The UK uses a mix of energy resources. The proportion of renewables is increasing as the government works towards net zero carbon emissions. Natural gas currently provides the largest share of UK electricity. Coal use has fallen dramatically.
Energy for Transport and Heating
Electricity generation is not the only use of energy resources:
- Transport mainly uses petrol and diesel (fossil fuels), but electric vehicles are growing
- Heating mainly uses natural gas (boilers), but heat pumps and biomass boilers are alternatives
Exam Tips
- Be prepared to compare two named resources, giving advantages and disadvantages of each
- Remember that "renewable" does not mean "no environmental impact" — all resources have some effect
- Questions often ask you to evaluate whether a resource is suitable for a particular location