Energy Resources

Types of Energy Resources

Energy resources are the sources from which we obtain energy to power homes, transport, and industries. They are broadly divided into two categories:

Renewable Energy Resources

Renewable resources can be naturally replenished in a short time and will not run out. Examples include:

• Solar energy – energy from the Sun captured by solar panels.
• Wind energy – generated using wind turbines.
• Hydroelectric power – energy from flowing water, often using dams.
• Biomass – energy from burning organic matter like wood or plant waste.
• Geothermal energy – heat energy from beneath the Earth’s surface.
• Tidal energy – energy from the movement of tides.

Non-Renewable Energy Resources

Non-renewable resources are finite and will eventually run out because they take millions of years to form. Examples include:

• Fossil fuels – coal, oil, and natural gas formed from ancient plants and animals.
• Nuclear fuel – uranium used in nuclear power stations.

For example, coal is mined from the Earth and burned to generate electricity, but once used, it cannot be replaced on a human timescale.

Advantages and Disadvantages of Energy Resources

Each energy resource has pros and cons related to reliability, cost, and environmental impact (though detailed environmental issues are covered elsewhere; see related notes for more information).

Reliability

• Non-renewable resources like coal and gas provide a steady and reliable supply of energy because they can be burned whenever needed.
• Renewable resources such as solar and wind are less reliable because they depend on weather conditions (sunlight or wind availability).
• Hydroelectric power is more reliable than solar or wind but depends on water availability.
• Nuclear power stations provide a very reliable and continuous supply.

Cost

• Fossil fuels are often cheaper to extract and use but prices can fluctuate with supply and demand.
• Renewable energy technologies usually have high initial installation costs but low running costs.
• Nuclear power plants are expensive to build and decommission but have low fuel costs.

Environmental Impact (Brief Overview)

• Burning fossil fuels releases greenhouse gases and pollutants (covered in environmental issues notes).
• Renewables generally produce little or no direct pollution during operation.
• Nuclear power produces radioactive waste that must be carefully managed.

Energy Resource Uses

Energy resources are used in various ways, including:

Electricity Generation

• Most electricity in the UK is generated by burning fossil fuels, nuclear power, and increasingly from renewables like wind and solar.
• Power stations convert chemical or nuclear energy into electrical energy.

Heating

• Natural gas is commonly used for heating homes and water.
• Electric heaters use electricity generated from various sources.
• Biomass can be burned for heating in some homes.
• Geothermal energy can provide heating in some areas.

Transport

• Petrol and diesel (from oil) are the main fuels for cars and other vehicles.
• Electric vehicles use electricity stored in batteries, which may be charged from renewable or non-renewable sources.
• Biofuels, made from plant materials, can also be used in transport.

For instance, petrol is a non-renewable resource used widely in transport, while electric cars rely on electricity that can come from renewable or non-renewable sources.

Comparing Energy Resources

When comparing energy resources, consider:

Efficiency

Efficiency is how well an energy resource converts its stored energy into useful energy.

• Fossil fuel power stations typically have efficiencies around 35-40%.
• Nuclear power stations have similar efficiencies.
• Renewable sources like wind and solar have no fuel cost but conversion efficiency varies (solar panels around 15-20%).

Sustainability

Sustainability means the resource can be used without running out or causing long-term damage.

• Renewables are sustainable because they naturally replenish.
• Non-renewables are not sustainable as they will eventually be depleted.

Availability

Availability depends on location, technology, and resource quantity.

• Fossil fuels are widely available but unevenly distributed globally.
• Renewables depend on local conditions: solar is best in sunny areas, wind in windy regions.
• Nuclear fuel is available but requires careful handling and supply chains.

For example, the UK has good wind resources, making wind power a growing energy source, but less geothermal potential.

Example: Calculating Efficiency of a Power Station

If a coal power station produces 400 MW of electrical power but burns fuel with an energy input of 1000 MW, its efficiency is:

$\text{Efficiency} = \frac{\text{Useful energy output}}{\text{Total energy input}} \times 100\%$

$\text{Efficiency} = \frac{400}{1000} \times 100\% = 40\%$