Energy from Fuels | Physics for GCSE/IGCSE - Year 11 PDF Download

Fossil Fuels

• Fossil fuels refer to coal, natural gas (predominantly methane) utilized in household heating systems and cookers, and crude oil that undergoes refinement to produce petrol, diesel, and various other fuels.

• Fossil fuels are created from the remnants of plants and animals.
• Chemical energy stored in fossil fuels originally derived from sunlight.
  • Energy from the sun was converted to the chemical energy store of plants through photosynthesis.
  • Animals consumed the plants, transferring the energy to their chemical store.

Advantages

• Current transportation and electricity systems heavily depend on fossil fuels due to their abundant availability.
• Historically, fossil fuels were pivotal for large-scale energy production, but their reliability is shifting with depleting supplies and escalating prices.

Disadvantages

• Fossil fuels take millions of years to form, rendering them non-renewable resources.
• The escalating demand coupled with a diminishing supply leads to price hikes, with predictions indicating a complete depletion within the next 200 years.
• The combustion of fossil fuels releases harmful gases like carbon dioxide, contributing to the greenhouse effect, and sulphur dioxide, which leads to acid rain.
• While technologies exist to capture these gases before they are released into the atmosphere, the process is costly.

Usage of Fossil Fuels

Fossil fuels serve various purposes:

• Transportation
• Electricity generation
• Heating

Transport

• Most vehicles globally run on petroleum derivatives like gasoline, diesel, and kerosene, all derived from crude oil, a fossil fuel.
• An increasing number of vehicles are adopting electric power.
• The benefit of electric vehicles is their zero carbon emissions during operation.
• However, a drawback is that during charging, they rely on the National Grid, which currently employs both renewable and non-renewable energy sources.

Electricity Generation

• Fossil fuels like coal and oil are utilized for generating energy instantly as needed.
• When coal is burned, energy is released from its stored chemicals.
• This energy is then employed to heat water, producing steam.
• The steam is directed through a turbine, which sets coils in motion within a magnetic field in the generator.
• As a result, electricity is generated in the process.
• Finally, the electricity is transmitted via a step-up transformer and conveyed through electrical lines.
• The steam produced in the turbine is condensed and then cycled back into the boiler for reuse.

• The demand for electricity is at an all-time high due to the global population of nearly 8 billion people.
• Meeting this demand requires a diverse mix of energy resources.
• The high demand for electricity necessitates the use of all available energy resources.
• However, a significant portion (84%) of the world's energy is derived from non-renewable sources that harm the environment.
• Efforts are underway to develop more sustainable methods of electricity production using carbon-neutral resources.

Heating

• Most residences in colder regions use central heating systems that run on natural gas to warm water, circulated through radiators for home heating.
• These systems efficiently utilize natural gas for heating purposes.

Bio Fuels

• Biofuels are derived from plant materials where the energy from sunlight is captured and stored in the plants.
• This stored energy can be converted into fuels like ethanol or methane, which can be used as alternatives to traditional fossil fuels.
• However, it's important to note that biofuels only have about half the energy density of fossil fuels.

Advantages

• Biofuels are considered a renewable resource since they are derived from plant matter.
• Vehicles can be powered by biofuels, reducing the dependence on non-renewable fossil fuels.
• Additionally, biofuels are often deemed carbon-neutral, meaning they do not contribute to net carbon emissions in the atmosphere.
• Unlike the burning of fossil fuels, the use of biofuels does not produce sulfur dioxide, a harmful air pollutant.

Disadvantages

• Cultivating biofuel-producing crops requires a significant amount of time.
• This cultivation demands extensive land and resources that could otherwise be allocated to food production.
• Combusting biofuels emits carbon dioxide into the air.
• Despite this, it's deemed carbon neutral as plants absorb carbon dioxide during photosynthesis.

Nuclear Fuel

• Energy stored within atomic nuclei can be released through nuclear fission, where a nucleus splits into two, releasing energy.
  
• Nuclear power plants employ fission reactions to heat water, which in turn drives turbines to produce electricity.

Advantages

• No pollution is released into the atmosphere by nuclear power.
• Nuclear reactors are safe when functioning correctly and following stringent safety procedures.
• Regular rigorous safety checks are essential for nuclear power plants.
• Nuclear power stations can reliably produce large-scale electricity as needed.

Disadvantages 

• Uranium ore found in the ground is utilized for fission reactions, contributing to the generation of nuclear power. However, due to its limited availability, nuclear power is classified as a non-renewable resource.
• Nuclear fuels, integral to the process, lead to the production of radioactive waste. This waste necessitates long-term storage for thousands of years, which comes at a considerable cost.
• In the event of an accident at a nuclear reactor, there is a risk of radioactive waste leakage, potentially impacting vast areas and posing significant environmental hazards.