Alternatives to Fossil Fuels (Edexcel A Level Geography): Revision Note

Renewable & Recyclable Energy

Alternatives to Fossil Fuels

• To reduce carbon emissions and to decouple fossil fuels from economic growth, the world must look to increase its use of alternative sources of ‘clean’ energy

• Alternative sources of ‘clean’ energy can be categorised into:

  • Renewable sources such as hydro, wind, solar, geothermal and tidal energy

  • Recyclable sources such as nuclear power and biofuels

Renewable Energy

• Currently, the main sources of renewable energy are hydro, wind, solar (mainly via photovoltaic cells), geothermal and tidal

• The contributions of renewable energy sources to the energy mix vary from country to country

• The physical geography of a country will determine whether they have renewable energies to exploit

  • Not all countries will have coasts or ‘hot rocks’ heated by magma for use in geothermal energy

  • Not all countries have a warm climate with long sunshine hours

  • Not all countries have permanently flowing rivers or strong winds

•  Whilst it is often claimed that renewable sources are the answer to our global energy challenge, there are some factors to consider

Evaluation of Renewable Energy

Recyclable Energy

• Countries with high levels of energy consumption will often have no choice but to consider nuclear energy to generate electricity (with low carbon emissions)

• An additional benefit to this is that nuclear waste can be reprocessed and reused, making it recyclable

• However, there are issues associated with using nuclear energy:

  • Safety - nuclear incidents such as Chornobyl (Ukraine) and Fukushima (Japan)

  • Disposal of highly toxic radioactive waste (which has a long decay life) 

  • The technology used means that nuclear energy is only really open to the most developed countries

  • Costs - despite operational costs being relatively low, the cost of building and decommissioning is high

  • Security of nuclear-powered stations at a time when international terrorism is a concern  

Biofuels

Biofuels

• Biofuels are derived directly from living matter, such as agricultural crops, forestry or fishing products and various forms of waste

• There are two types of biofuels:

  • Primary biofuels, which include fuelwood, wood chips and pellets that are used unprocessed for heating, cooking or electricity

  • Secondary biofuels are derived from the processing of crops (e.g., sugar cane, soybeans and maize), where two types of fuel are extracted (bio-alcohol and biodiesel), which are used to fuel vehicles and generate electricity

• More attention is now being given to the growing of biofuel crops as a way of reducing the use of fossil fuels

• Biofuel crops that can be used include wheat, maize, grasses, soybeans and sugar cane

• In the UK, the two main crops that are used are oilseed rape and sugar beet

• Most of these biofuels are converted into ethanol or biodiesel and used mostly as vehicle fuel

• Whilst biofuels can be considered a ‘green’ source of energy, there are disadvantages, for example, the implications this can have on food supply

  • For example, a hectare of space used to grow energy crops is a hectare less for growing much-needed food

Biofuels in Brazil

• Brazil began to diversify its energy sources in the 1970s in order to improve its energy security

• Brazil is now the largest producer of sugar cane and has become the leading exporter of sugar and ethanol

• Since 2003, the area used for sugar cane has increased massively and is likely to continue, which has led to the displacement of other types of agriculture, e.g., cattle pasture

Radical Technologies

Carbon Capture and Storage

• It is accepted that coal will always be part of the global energy mix due to its abundance and its low cost

• Carbon capture and storage involves ‘capturing’ the carbon dioxide released and burying it deep underground

• However, carbon capture and storage have significant challenges

  • It is expensive because of the advanced technology required

  • No one can be sure that the carbon dioxide will stay underground and that it will not leak to the surface and enter the atmosphere

Electric vehicles

• Electrically propelled vehicles (electric cars, scooters, buses) use electricity instead of fossil fuels

  • They produce no exhaust emissions during use

  • Help reduce overall fuel consumption

• However, the electricity to power them may have been generated using fossil fuels

Hydrogen Fuel Cells

• Hydrogen is a chemically simple and abundant element but it does not occur naturally as a gas; it is always combined with other elements, e.g., oxygen in water

• Currently, most hydrogen is extracted from other forms of fuel, e.g., oil and natural gas

• Hydrogen is high in energy and an engine that burns pure hydrogen produces next to no pollution

• A fuel cell combines hydrogen and oxygen to produce electricity, heat and water

• A fuel cell will provide electricity as long as hydrogen is supplied and it will never lose its charge

• Fuel cells are a promising technology for use as:

  • A source of heat and electricity for buildings

  • A power source for electric vehicles

• Hydrogen fuel cells are considered to be one of the best strategies for reducing carbon emissions, which has very little impact on the carbon cycle