Fossil Fuels: Environmental and Economic Aspects

Non-renewable Energy Sources

• Non-renewable energy sources will eventually run out
• Non-renewable energy sources include fossil fuels and nuclear energy using uranium

Fossil Fuels

• Fossil fuels are carbon-based, formed from the decay of living matter under heat and pressure over millions of years
• Fossil fuels include coal, natural gas (mostly methane, used in domestic boilers and cookers), and crude oil (refined into petrol, diesel, and other fuels)
• Fossil fuels originate from the remains of plants and animals, with the chemical energy initially coming from sunlight
• Energy from the sun is transferred to plants through photosynthesis, then to animals that eat the plants, and finally to the chemical store within the fossil fuels
• Fossil fuels form from the remains of dead plants and animals buried in the Earth's crust, compressed by heat and pressure
• Oil and natural gas mainly form from dead marine organisms

Coal Formation

• Coal forms as plants die and sink to the bottom of swamps
• Over time, layers of plants are covered by dirt and water, packed down by sediments
• After a long time, heat and pressure change the plants into coal

Natural Gas and Oil Formation

• Natural gas and oil are formed from the remains of sea creatures
• Small marine animals and plants die and fall to the sea bottom, their remains covered by sediments
• Heat and pressure transform these remains into crude oil and natural gas
• Oil and gas is trapped underneath nonporous rock

Advantages of Fossil Fuels

• Transport and electricity generation rely on fossil fuels for ready availability on a daily basis
• Fossil fuels have been reliable for large-scale production but this is changing
• Fossil fuels have high energy density, producing a large amount of energy per kilogram

Disadvantages of Fossil Fuels

• Fossil fuels take millions of years to form, making them non-renewable
• The increasing demand for a decreasing supply causes prices to rise
• Fossil fuels are predicted to run out within the next 200 years
• Burning fossil fuels pollutes the atmosphere with carbon dioxide (greenhouse effect) and sulphur dioxide (acid rain)
• Capturing carbon and sulphur upon burning is expensive
• Oil spills during transport damage the environment and wildlife
• Prices fluctuate rapidly
• Supplies depend on conflict and political disagreements

Uses of Fossil Fuels

• Main uses are for transport, generating electricity, and heating
• Most vehicles are powered by petroleum products like petrol, diesel, and kerosene, originating from crude oil
• An increasing number of vehicles are transitioning to electricity
• Electric vehicles produce zero carbon emissions while driving but can be connected to a grid with non-renewable sources

Electricity Generation with Fossil Fuels

• Coal and oil are burned to produce energy on demand
• Burning coal produces heat (thermal) energy to boil water and create steam
• Steam turns a turbine, which turns coils in a magnetic field (generator) to generate electricity
• Electricity is transferred through a step-up transformer and electrical lines, and steam within the turbine is cooled, condensed, and pumped back to the boiler

Energy Demand

• Global energy demand is rising due to population growth and development
• Increased demand for food leads to more intensive farming, requiring more energy
• More industry requires energy for heating, lighting, and machinery
• Increased transport requires petrol, diesel, or electricity
• Urbanisation increases with development, increasing domestic appliances, heating, and lighting
• Increased wealth means people buy more energy-consuming appliances and technology

Nuclear Energy

• Energy stored in the nucleus of uranium atoms can be released through nuclear fission
• Nuclear power stations use fission reactions to create steam that turns turbines to generate electricity
• Nuclear power offers low carbon, low emission energy but has non-renewable resource concerns due to the radioactive waste and the potential accident scale

Advantages of Nuclear Energy

• No pollution is released into the atmosphere
• Nuclear reactors are safe if functioning properly with rigorous safety checks
• Nuclear stations can generate electricity reliably on a large scale
• Uranium is needed in small amounts and has large reserves
• It Reduces reliance on fossil fuels and increases energy security

Disadvantages of Nuclear Energy

• Uranium is used for fission reactions, so nuclear power is non-renewable
• Nuclear fuels produce radioactive waste that needs storage for thousands of years
• Safe storage of radioactive waste is very expensive
• A nuclear reactor accident can cause radioactive waste to leak and spread
• Decommissioning (shutting down) a nuclear power plant is costly

2019 Nuclear Energy Supply

• Approximately 4% of the global primary energy supply was from nuclear power in 2019
• 439 active nuclear reactors exist across the world in USA, France, China Russia and Japan

Renewable Energy Sources

• Renewable energy will not run out

Renewable Energy Sources

• Includes biofuels, geothermal energy, hydroelectric dams, and tidal energy
• Wave, solar, and wind energy also included
• Do not produce greenhouse gas emissions once in place (except biomass), but are emitted during production, construction and transport of the equipment

Biofuels

• Biofuels (biomass fuels) are derived from organic materials and used as an alternative to fossil fuels
• Have only half the energy density of fossil fuels
• Biodiesel is made by refining renewable fats and oils, bioethanol by fermentation of crops rich in sugars or starches, and biogas released when waste products decompose

Advantages of Biofuels

• They are a Renewable resource, use waste or bio products that can be regrown, some vehicles can be powered by biofuel rather than fossil fuels and no sulfur dioxide is produced
• It is considered Carbon neutral

Disadvantages of Biofuels

• Crops of biofuel producing plants must be grown, which takes time
• Growing the crops takes a lot of land/resources and burning biofuels releases carbon dioxide (carbon neutral, plants take in carbon dioxide when they photosynthesize)

Geothermal Energy

• Geothermal energy is caused by heat from within the Earth by radioactive elements
• Geothermal energy heats rocks in the Earth's crust
• The surface of water is poured into underground shafts, heated, and returned as steam or hot water
• Steam is used to turn a turbine, generate electricity, and hot water is used to heat homes

Advantages of Geothermal Energy

• It is a Renewable Resource, and a reliable source of energy
• Geothermal power stations are small to nuclear or fossil fuel power stations

Disadvantages of Geothermal Energy

• Few locations, but can power small-scale electricity production and can release greenhouse gases from underground
• It is Expensive to build and maintain

Hydroelectric Dams

• Water stored above ground has gravitational potential energy
• Energy transfers to kinetic energy if the water flows down the slope and flowing water then turns a turbine to generate electricity

Advantages of Hydroelectric Dams

• Can respond to demand quickly, can generate large-scale electricity and are often put in sparsely populated areas

Disadvantages of Hydroelectric Dams

• They are Expensive to build and maintain and creating reservoirs could flood valleys
• Pumping water also relies on fossil fuels
• Dams trap sediment which can affect ecosystems, can cause visual pollution and can prevent fish movement

Wave and Tidal Energy

• The rise and fall of waves/tides are used to turn a turbine and generate electricity

Advantages of Wave and Tidal Energy

• This causes No pollution, reliable and produce electricity fast
• They are renewable and can provide electricity in small islands

Disadvantages Wave and Tidal Energy

• They are Expensive to build and maintain can damages fragile habitats
• There are Very few suitable locations that are not advanced enough for large-scale electricity production

Solar Energy

• Uses photovoltaic cells that produce a small electric charge with sunlight
• A bank of cells organized into solar panels makes electricity

Advantages of Solar Energy

• It is a renewable resource that is a reliable energy resource
• Solar farms produce no greenhouse gases
• They can be used in remote places to power signs and are small or large scale

Disadvantages of Solar Energy

• Solar farms need scales to produce electricity and are expensive
• Uses large areas of land and sunlight in unreliable

Wind Energy

• Wind energy harnesses power of the wind to generate electricity
• It involves the use of wind turbines, which have large blades that spin when the wind blows
• The rotating blades transfer kinetic energy to a generator to convert it into electrical energy

Advantages of Wind Energy

• Always available and produces no harm for air pollution
• Reduces wind farms creating jobs
• They are cheap and can be big or small

Disadvantages of Wind Energy

• Not constant, depends on consistency and wind speed
• It is visually intrusive and can disrupt a lot
• The turbines can affect wild life too

Explore the non-renewable nature and environmental concerns related to fossil fuels, like sulfur dioxide emissions. Consider the economic and long-term consequences of their increasing demand. Analyze the role of marine organisms and sediments in fossil fuel formation.