Renewable Energy (Cambridge International IGCSE Geography)

Importance of Renewable Energy Sources

Spec point — 3.5.2 · Importance of renewable energy supplies globally and in different countries at different levels of development

• Renewable energy sources are infinite and will not run out. They include:

  • hydroelectric
  • wave/tidal
  • wind
  • solar
  • geothermal
  • biomass/waste

• Once in place, except for biomass/waste, they do not produce any greenhouse gas emissions

• Greenhouse gases may be emitted in the production, construction and transport of the equipment

Increase in renewable energy

• Renewable energy is increasingly important in the global energy mix

• This is due to:

  • Non-renewable fossil fuels will at some point run out and so they need to be replaced with another energy source

  • The use of non-renewable fuels is damaging to the environment.

    • Fossil fuels, when burnt, release greenhouse gases and the sulphur dioxide released causes acid rain
    • Mining and drilling for fossil fuels can destroy habitats and damage the surrounding environment

  • Increasing awareness of the impact of using fossil fuels has resulted in international pressure to reduce their use

  • Countries wanting to reduce their reliance on imports of energy sources and improve their energy security

Advantages and disadvantages of renewable energy sources

Hydroelectric energy

Advantages

• No greenhouse gas emissions
• Controls flooding downstream
• Often in sparsely populated areas
• May provide water storage for irrigation and domestic use

Disadvantages

• Large areas of land are flooded behind the dam
• Dams trap sediment, which can affect ecosystems downstream
• Visual pollution
• Can prevent fish movement upstream
• People and settlements may have to be relocated
• Expensive to build and maintain

Wave/tidal

Advantages

• No greenhouse gas emissions
• No air pollution
• Has the potential to produce large amounts of energy
• Reliable

Disadvantages

• Expensive to build and maintain
• Can affect marine ecosystems
• Few suitable sites

Wind

Advantages

• No greenhouse gas emissions
• No air pollution
• Can be small or large scale
• Cheap to run
• Can be on land or offshore

Disadvantages

• Not reliable only works when the wind is strong enough but not too strong
• Visual pollution
• Noise pollution
• Many turbines (233) are needed to produce the same energy as an average coal-fired power station
• May affect bird migration patterns or kill birds who fly into the moving blades

Solar

Advantages

• No greenhouse gas emissions
• No air pollution
• Can be small or large scale
• Can be used in most locations
• Can be incorporated into building design
• Technology is improving and reducing cost

Disadvantages

• Expensive to install
• Not reliable; only works when it is sunny
• Large numbers needed to produce energy
• Uses large areas of land

Geothermal

Advantages

• A reliable source of energy
• Lower greenhouse gas emissions
• Produces hot water as well as electricity

Disadvantages

• Expensive
• Emits sulphuric gases
• High temperatures cause maintenance issues

Biomass/waste

Advantages

• Uses waste or biofuels that regrow
• Available in most locations

Disadvantages

• Air pollution
• Produces greenhouse gases
• Expensive

Exam Hint Remember, reducing fossil fuel use is not as easy as simply switching to renewable energies. Although the costs are coming down, renewable energy is often still more expensive than using fossil fuels, and they are generally not as efficient. This means you need far more to produce the same amount of electricity.