Fossil Fuels

Fossil fuels:: non-renewable natural resources formed from the remains of organisms

The three main fossil fuels are coal, oil and gas. These are burned to produce electricity in power stations.

In the past, fossil fuels have been the UK’s main source of power. However, there has recently been a shift towards renewable energy sources.

Advantages:

• Generate large amounts of cheap energy

• Provides a reliable supply of energy

Disadvantages

• Release greenhouse gases, which cause pollution

• Contributes to global warming

• Will run out

Renewable Energy

Wind

Generators in turbines convert the wind’s kinetic energy into electricity.

No greenhouse gases are produced. Cheap to run.

High set up costs. Turbines are ugly. Noise pollution.

Solar

Solar panels convert the Sun’s energy into electricity.

No greenhouse gases are produced. Cheap to run.

No sunlight - no electricity. Solar panels are expensive.

Tidal

Turbines convert the current’s kinetic energy into electricity.

Tides are guaranteed. No greenhouse gases are produced.

Tidal barrages are expensive. Tidal barrages can disrupt ecosystems.

Hydroelectric

Turbines in dams convert kinetic energy into electricity.

Cheap to run. The reservoirs needed supply water during shortages.

Expensive to set up. Dams destroy habitats.

Biomass

Organic material is burnt for steam.

Renewable if resources are replaced.

Releases CO2. Can lead to deforestation.

Nuclear Power

Heat/steam is generated by splitting uranium atoms in nuclear reactors.

Very efficient. Produces little greenhouse gases.

Depends on a non-renewable source. Radioactive waste is hard to dispose of. High set-up and decommissioning costs.

Energy Storage Systems

Energy storage systems are needed because demand for energy fluctuates.

Kinetic Pumped Storage Systems

Excess energy is used to pump water from a low reservoir to a high reservoir when demand is low.

When demand is high, the water is released to generate more energy

Batteries

Batteries store energy in a chemical form for conversion into electricity when needed.

Dry-cell batteries are non-rechargeable, so once the reactants inside them have run out, they cannot be used anymore.

The toxic chemicals in batteries can harm the environment, so they must be disposed of properly.

Alkaline batteries

These are disposable and non-rechargeable. They leak less than other batteries and last a long time. However, their output gradually decreases.

Rechargeable batteries

These batteries can be recharged and thus are better for the environment. They maintain a constant output.

Charging reverses the chemical reaction that occurs during use.