Energy Sources for Society

Unit 4: Area of Study 2Supplying and Using Energy

Study DesignTopic Description

» Students evaluate the extent of the reserves of some of these resources, how each resource is used and the advantages and disadvantages of their continued use.

Study DesignOutcome Dot Point

»comparison of the renewability of energy sources including coal, petroleum, natural gas, nuclear fuels and biochemical fuels.

What is Energy?» Energy cannot be directly seen so it is a

concept that is often difficult to comprehend.» Energy is defined as the ability to do work.» The unit of measurement for energy is the

joule (J)» 1 joule of energy is a relatively small amount

of energy.» It takes 70 000 J of energy to boil water for a

cup of coffee.

Energy from Common Fuels

» A substance used for producing energy by combustion is called a fuel.

» Coal, Petroleum and natural gas are also known as fossil fuels.

» This is because they were formed from the decaying remains of plants and tiny marine animals that lived millions of years ago.

Combustion Reactions

» Most of the energy obtained from the combustion of fossil fuels is derived from an exothermic reaction in which the carbon in the fuel is converted to carbon dioxide and the hydrogen is converted to water.

Energy use in society

» About 80% of the world’s energy requirements are provided by the fossil fuels coal, oil and gas.

» In Australia, about 95% of our energy requirements are provided by fossil fuels.

» In Victoria, we have over 100 years supply of black coal, 500 years of brown coal and 90 years of natural gas reserves based on current usage.

Renewable vs. Non renewable resources

» Non-renewable resources are those that are used up faster than they can be produced on Earth.

» E.g. include fossil fuels and nuclear fuels.

» Renewable resources are those that can be produced faster than they are used in society.

» E.g. include solar, hydro-electric, wave, wind, geothermal and biogas.

Secondary Fuels

» Electricity is sometimes described as a secondary fuel, since it is not a natural source of power. It is produced from other fuels or energy sources.

Non-renewable fuels.

» FOSSIL FUELS» COAL» PETROLEUM» LPG» NATURAL GAS

» READ PAGE 276-277 for more detailed information.

NUCLEAR ENERGY

» A large amount of energy is stored in the nucleus of an atom.

» An attractive force, known as the strong nuclear force, holds protons and neutrons together in the nucleus.

» If the nuclei of two atoms come close enough together, they can interact via nuclear reactions.

NUCLEAR FISSION

» NUCLEAR FISSION occurs where the nucleus of an atom breaks apart into two fairly large fragments.

» In doing so a huge amount of energy is released.

RADIOACTIVE DECAY

» Radioactive decay is different to nuclear fission.» Radioactive decay is the spontaneous disintegration of unstable

nuclei.» Radioactive decay produces one large fragment and one very

small fragment (generally an alpha particle, beta particle or gamma particle).

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NUCLEAR POWER STATIONS

» In a nuclear power station, the energy released when atoms split is used to make electricity.

» The key principle is that the energy released is used to heat water a produce steam. The steam is then used to spin turbines, which are basically rotating magnets.

» A spinning magnet can then be used to generate electricity.

NUCLEAR FUSION

» Nuclear fusion is not a viable energy source as the reaction is too difficult to contain.

» Nuclear fusion requires extreme temperatures and pressures.» Nuclear fusion occurs in the Sun.

NUCLEAR FUSION

» A large amount of energy is released when nucleons fuse.

» The mass of the nucleus is lighter than the combined mass of the individual components.

» This mass has been converted into energy by

NUCLEAR FUSION

» Once a nucleus has formed, it would require the same amount of energy to break down into individual protons and neutrons.

» This is called the nuclear binding energy.

Writing Nuclear Equations

» The sum of the mass numbers and atomic numbers of the reactants equals the sum of the mass numbers and atomic numbers of the products.

Writing Nuclear Equations

» The sum of the mass numbers and atomic numbers of the reactants equals the sum of the mass numbers and atomic numbers of the products.

RENEWABLE FUELSSOLAR ENERGY

» Solar energy is the radiant heat and light energy given out from the Sun.

» The Earths receives more solar energy in one month than the total energy in all the fossil fuels we have left.

» There are two problems:˃ Collecting and concentrating the Sun’s energy.˃ Storing the Sun’s Energy

RENEWABLE FUELSENERGY FROM WATER

» HYDROELECTRICITY˃ Uses the kinetic energy of falling water to spin turbines.

» TIDAL POWER˃ Uses the kinetic energy of moving water to spin turbines.

» WAVE POWER˃ Is difficult to harness and is currently being investigated.

RENEWABLE FUELSWIND POWER

» Uses the kinetic energy of moving air particles to spin wind turbines.

» Wind speed increases with height above the ground.

RENEWABLE FUELSGEOTHERMAL

» Uses the heat trapped within the Earths surface to heat steam.» This steam can then be used to spin turbines.

RENEWABLE FUELSENERGY FROM BIOMASS

» BIOETHANOL˃ Is produced from the fermentation of sugar from sources such as waste

wheat starch.˃ Reduces emission of CO

» BIODIESEL˃ Alkyl ester produced from vegetable oil.˃ Reduces sulphur dioxide emissions.

» BIOGAS˃ Produced from rotting animal or organic waste in the absence of oxygen.˃ Can be up to 65% methane.

ENERGY USE AND THE ENVIRONMENT

» ENHANCED GREENHOUSE EFFECT˃ Human sourced emissions of greenhouse gases help to trap the sun’s energy

which can lead to climate change and a warming of Earth’s mean surface temperature.

» ACID RAIN˃ Occurs from the reaction of rainwater and sulphur dioxide that is released

into the Earth’s atmosphere.

ENERGY USE AND THE ENVIRONMENT

» SUSTAINABLE ENERGY˃ A sustainable energy future means providing for the needs of today’s

society without compromising the ability of future generations to meet their own needs.

+ promoting energy conservation in the domestic, commercial and industrial

+ sectors+ funding research into producing viable alternative energy sources+ decreasing our dependency on coal by using more renewable sources+ increasing the efficiency with which energy is produced from each

resource+ developing technologies to reduce emissions when using fossil fuels.

PAST VCAA EXAM QUESTIONS

PAST VCAA EXAM QUESTIONS

PAST VCAA EXAM QUESTIONS

PAST VCAA EXAM QUESTIONS

ENERGY SOURCES FOR SOCIETY QUESTIONS

»Review Q1-22 pg. 295»To achieve an S,

complete every 3rd question.