ENERGY AND ENVIRONMENT (Fossil fuel formation) IGCSE Environmental Management 0680

 ENERGY AND ENVIRONMENT

Fossil fuel formation

 

•  Fossil fuels: carbon-based fuels, formed many millions of years ago from the decay of living matter.

 

•  Coal: formed from plants.

 

•  Oil and natural gas: formed from sea creatures.

Formation of coal:

 

·            Huge forests grew millions of years ago covering most of the Earth.

 

·        The vegetation died and formed peat.

 

·        The peat was compressed between layers of sediments to form lignite (low-grade coal).

 

·        Further compression formed coal.

 Formation of oil and natural gas:

·        Small animals and plants die and fall to the bottom of the sea.

·        Their remains are covered by sediments.

·        As the sediments start forming layers, they start to change into sandstone as the temperature and pressure increase.

 

·        The heat and pressure turn the remains into crude oil and natural gas.

 

·        They separate and rise through the sandstone, filling in the pores.

 

·           The rock above the oil and gas is impervious (non-porous).

 

·           So, they get trapped underneath it.

Energy resources and the generation of electricity

 

•  The demand for energy is increasing worldwide due to:

 

-         Increasing population size.

 

-            Increasing industrialization and urbanization.

 

-            Improvements in standards of living and expectations.

 

Types of energy sources:

NON-RENEWABLE		RENEWABLE
Limited.		Can be used over and over
		again.
Take millions of years to get		Can be replenished in a short
replenished.		period of time.
•Fossil fuels (coal, oil and		•Geothermal power;
natural gas);		• Hydro-electric power;
• Nuclear power (using		• Tidal power;
uranium).		• Wave power;
		• Wind power;
		• Solar power;
		• Biofuels e.g. bioethanol,
	biogas and wood.

How energy sources are used to generate electricity:

 

·        Most electricity is generated by electromagnetic induction which transforms kinetic energy into electric energy.

 

·        Turbine: a machine, often containing fins, that is made to revolve by gas, steam, or air (it is connected to a generator).

·         Generator: a machine that converts mechanical energy into electrical energy.

Fossil Fuels and Biofuels:

 

·        These produce a massive amount of energy during combustion that is used to heat water and convert it into steam, which thereby drives the turbines.

Nuclear Power:

 

·        Uranium, a radioactive element, releases huge amounts of energy when nuclear fission (splitting of the atom) occurs.

 

·        This energy is used to heat the water, produce steam, and rotate the turbines.

Geothermal Power:

 

·        Cold water is pumped under pressure into a layer of hot rocks.

•   The rocks heat the water.

The hot water returns to the surface under pressure and heats the second supply of water using a heat exchanger.

·         The steam produced in the second supply moves the turbine, generating electricity.

Wind Power:

 

·        Wind turbines have shafts (blades) that rotate due to wind.

 

·        Gearbox maximizes the rotation of the shaft.

 

·        Brakes slow down or stop the rotor in very windy conditions, preventing damage to

 

the blade.

 

·        As the turbine rotates, the generator produces electricity.

Solar Power:

 

·        Uses photovoltaic cells that produce a small electric charge when exposed to light.

 

·        A bank of cells organized into solar panels produces a significant amount of electricity.

Tidal Power:

 

·        Uses the natural rise and fall in the level of water in an area.

·        When the levels drop, water is held back by a tidal barrage (a small dam that releases water back through a turbine).

Wave power:

 

·           Also uses turbine and generator.

 

·        Uses the smaller differences in water levels that are caused by wind.

Hydro-electric Power:

 

 

·        Uses a dam on a river to store water in a reservoir.

 

·        Water is released from the reservoir that flows through the turbine, rotating it.

 

·           

The turbine then activates a generator that generates electricity.

Advantages and Disadvantages of:

 

Fossil Fuels:

 

ADVANTAGES:

 

·        Plentiful supply

 

·        Provides job opportunities (mining and processing)

 

·        The technology used is well-known and the methods of extraction are well-practiced.

 

DISADVANTAGES:

 

·        Carbon dioxide and toxic gases are released when burnt (contributes to global warming).

 

·        • Damages local area.

 

·        Limited supply (non-renewable).

 

 

Biofuels:

 

ADVANTAGES:

 

·        Renewable source

·        Growing more plants use carbon dioxide.

·        Plentiful supply

 

DISADVANTAGES:

 

·        Carbon dioxide and toxic gases are released when burnt.

 

·        Lot of lands needed

·        Shortage of land for agriculture (increase in food prices).

·        Removal of natural ecosystems (reduction in biodiversity).

 

Nuclear Power:

 

ADVANTAGES:

 

·           Does not produce carbon dioxide.

 

·        Large amount of energy is produced with a small amount of fuel.

 

·        Provides job opportunities.

 

DISADVANTAGES:

 

·        Risk of radiation leakage.

 

·        Radioactive waste cannot be recycled since it is active for centuries;

·           Limited supply (non-renewable).

 

 

Geothermal Power:

 

ADVANTAGES:

 

·        Does not produce carbon dioxide (doesn’t contribute to global warming).

·        Unlimited supply (renewable).

 

DISADVANTAGES:

·           Expensive to install.

·           Only certain areas have suitable conditions.

 

  

Wind Power:

 

ADVANTAGES:

·        Does not produce carbon dioxide (doesn’t contribute to global warming).

·        Renewable.

·        Very low cost once built

 

DISADVANTAGES:

·        Generation of electricity is weather-dependent.

·        Only certain locations are suitable;

·        Visual impact.

·           Uses a large area.

 

Solar Power:

 

ADVANTAGES:

·        Does not produce carbon dioxide (doesn’t contribute to global warming).

·        Costly to build

 

DISADVANTAGES:

 

·        Weather-dependent.

Tidal Power:

 

ADVANTAGES:

 

·        Does not produce carbon dioxide ؞ doesn’t contribute to global warming.

 

·        Tidal movements are not weather-dependent.

 

.DISADVANTAGES:

 

·           Limited to specific coastal areas

·           impact on tourism and local fishermen.

 

Wave Power:

 

ADVANTAGES:

 

·        Does not produce carbon dioxide (doesn’t contribute to global warming).

·        Renewable.

 

 

DISADVANTAGES:

 

·        limited to specific areas.

·        Not very efficient at present.

  

Hydro-electric Power:

 

ADVANTAGES:

 

·        Does not produce carbon dioxide (doesn’t contribute to global warming).

 

·        Water can be reused

 

 

DISADVANTAGES:

 

·        Dams impact the natural flow of water.

Villages and ecosystems may be destroyed

Key Term:

Fossil fuel: a carbon-based fuel, formed over many millions of years from the decay of living matter. Non-renewable: an item or resource that exists in a finite amount that cannot be replaced.

 

Renewable: an item or resource that will not be used up or can be replaced.

 

Electromagnetic induction: a process used for generating electricity that uses the movement of a metal coil and a magnet.

 

Generator: a machine that converts mechanical energy into electrical energy.

 

Turbine: a machine, often containing fins that are made to revolve by the use of gas, steam, or air.

 

Solar power: harnessing energy from sunlight.

 

Tidal power: the use of tides (the natural change in sea level) to generate electricity.

 

Wave power: the use of changes in the height of a body of water to generate electricity.

Energy demand

 

Domestic demand:

 

·        The impact of a more efficient manufacturing process has meant that many goods have become more affordable.

 

·        Created by affordability, availability, and social status.

 

·        Most of the purchases that are considered as necessities now increase the demand for energy supplies, notably electricity.

 

-         Fruits and vegetables, that aren’t naturally available in the season locally, are produced in glasshouses or in areas with a favorable climate and are then transported.

 

-         In both scenarios (glasshouse operation and transport), the energy cost is significant.

 

Industrial demand:

 

·        Manufacturing requires the use of large amounts of energy throughout the production e.g. iron and steel production.

 

·        Advanced manufacturing techniques made the products that were once luxury items, cheaper.

 

-         So, more people want to buy them.

 

-         The demand for the product increases.

 

-         The demand for energy (needed for production) also increases.

 

Transport:

·        Manufacturers supply customers across the globe.

 

·        This decreases production costs in countries that import but increase the transport costs as they require large amounts of fossil fuels to operate.

 

·        There has been a significant increase in the amount of shipping and air transport journeys.

 

  

Economic factors:

 

Personal and national wealth:

 

·        If economic conditions are good:

-         Higher employment

-         More money to spend on luxury items;

-            Increase in demand for the product;

-         Increase in demand for energy (for production).

 

·        If economic conditions are poor:

 

-         Families have less money to spend on luxury items;

-         Need to make savings;

-         Reduce the use of fuel;

-         Reduce the purchase and use of electrical items.

-         Decrease in the demand for energy.

 

·       Decline in the economy of one country can have a global impact.

·        Ex.  Reduction in the economy of China meant a worldwide:

o   Reduction in production of steel.

o   Decrease in the number of manufactured goods (transported by ships).

o   Decrease in the price of oil (energy source).

 

Climate:

 

·        The demand for energy with regard to climate depends on the country.

·        People living in a temperate climate are likely to experience colder winters, so the energy demand for heating would be far higher.

·        They also experience fewer hours of daylight.

·        This increases the usage of electrical lighting.

·        Climate change (excessive heat or cold) increased energy consumption (particularly in urban areas).

·        Need for additional heating or Installation and operation of air-conditioning units.