The Future of Innisfail's Energy (GOOD)

8/21/2019 The Future of Innisfail's Energy (GOOD)

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Redeemer Lutheran College

The future of Innisfails

energyYear 12 Physics

Winston Boon


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Winston Boon | Yr. 12 Physics

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Assessment of InnisfailInnisfail is a town in Northern Queensland with a population of 7177. There are 2397

households in Innisfail (Australian Bureau of Statistics, 2014) . The average household in

Innisfail uses 1780.25kWh of energy per year.

Current energy sourcesThe coastal network between Townsville and Cairns supports the 275kV (220kWh) inland

main grid and delivers bulk electricity supply to Innisfail. As a result, the majority of

Innisfails energy is produced from current renewable energies implemented in the area.

These include the South Johnstone Sugar Mill and Windy Hill Wind Farm.

The South Johnstone Sugar Mill produces renewable energy by burning the bagasse

(biomass fuel) in sugarcane to generate electricity and steam for factory operations.

Significant quantities of the renewable energy are also exported to the electricity market

each year which reduces greenhouse gas emissions (MSF Sugar (Limited), 2013). Figure 1

in Appendix A shows the general schematic of any biomass (including bagasse) based

power plant. Sugar mills can be seen as an advantage as the juice from the bagasse is

extracted from the sugar cane for making sugar and other related products for the

designated area. Biomass is also carbon neutral as it is part of the carbon cycle. This is why

biomass fuels do not contribute to global warming thus making biomass fuels clean1.

Set aside the advantages of biomass, some disadvantages arise from the renewable source.

The extraction of biomasses can be expensive even though energy harnessed is inexpensive

thus making the overall process expensive. Biomass also requires big areas i.e. space for all

the different processes that are needed in harnessing energy from biomass (areas that are

needed for storing can be particularly large).The Windy Hill Wind Farm has 20 wind turbines with a registered capacity of 12MW (1.2 x

10-5kWh) of electricity, enough power to generate 3500 homes (Andrew Miskelly, 2014).

Windy Hill Wind Farm will reduce Australias greenhouse gas emissions by up to 0.625

million tonnes of CO2 equivalent during its forecast 25 year operating life. Investments in

renewable energy are seen as environmentally and commercially sustainable (Ratch

Australian Corporation, 2014). Figure 3 in Appendix Bshows the general turbine and the

key features that make the turbine work. Wind turbines can be seen as an advantage as

residential wind turbines yields energy savings and protects homeowners from power

outages meaning good domestic potential. Wind power also accounts for about 2.5% of total

worldwide electricity production, but is growing at a rate of 25% per year (Mathias AarreMhlum, 2013).

As well as the advantages of wind power, some disadvantages can be taken into account.

One of the disadvantages is that wind is unpredictable and the availability of wind energy is

not constant therefore not suited as a base load energy source. As well as being

unpredictable, it is also a threat to wildlife. This is a disadvantage for the native birds in the

designated area (Mathias Aarre Mhlum, 2013).

Both biomass and wind power are effective energy sources as well as cheap and reliable.

However, biomass and winder power will not last at the current rate of consumption. Thus,

1Refer to Appendix A (1) for continuation of advantages of biomass.


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a substitute energy source is required to sustain the future of Innisfails energy. Alternative

energy sources available to Innisfail include: solar power and biomass.

Alternative Energy SourcesSolar Energy

A 9.1kW solar panel for each home in Innisfail (producing 79716kW annually) would be the

best solution to supply Innisfail with renewable energy. Firstly, solar panels are reliable as

they are able to generate power 98% of the time (Victor Provenzano, 2013) and, if

necessary, can be brought up to 100%. In terms of cost, solar power has been one of the

most expensive sources of alternative energy, but recent research using magnetic fields to

collect solar energy without the need for expensive photovoltaic cells could dramatically

reduce its costs in the future (Gerlinda Grimes, 2011). This latest research using magnetic

fields to collect solar energy is called the Photomagnetic Effect which will be discussed in

physics of photomagnetic effect. In terms of efficiency, commercial cells that are often

made from silicon normally convert sunlight into electricity with an efficiency of only 10-

20%. Recent engineered experiments have found that using solar cells made of silicon

nanocrystals can theoretically reach efficiencies of about 60% or higher. This will be

discussed in physics of nanocrystals. In terms of sustainability, solar energy is one of the

cleanest energy sources, providing sustainable energy globally while providing energy that

never runs out. In terms of environmental factors, solar technology has a major impact on

the environment as it uses a vast amount of land space. The efficiency of an average solar

panel in Innisfail is approximately 12.88% (calculations in Figure 8 in Appendix D). The

solar panels would be about 8km in a north-west direction, away from Innisfail but close in

range as there is more space north-west of Innisfail.

Biomass was the second alternative to supply Innisfail with energy as there is an existingsugar mill called the South Johnstone Sugar Mill. Biomass is fairly cheap compared to other

renewable sources of energy

Reliability, economical, efficiency, availability, sustainability, environmental


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AppendicesAppendix A-

Figure 1- Biomass based power plant

Source:http://www.quora.com/What-is-the-concept-of-a-power-generation-in-sugar-mills
http://www.quora.com/What-is-the-concept-of-a-power-generation-in-sugar-millshttp://www.quora.com/What-is-the-concept-of-a-power-generation-in-sugar-millshttp://www.quora.com/What-is-the-concept-of-a-power-generation-in-sugar-millshttp://www.quora.com/What-is-the-concept-of-a-power-generation-in-sugar-millshttp://www.quora.com/What-is-the-concept-of-a-power-generation-in-sugar-millshttp://www.quora.com/What-is-the-concept-of-a-power-generation-in-sugar-mills


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Appendix A (1)-As such, energy harnessed from biomass is inexpensive compared to coal and oil as they

typically cost about 1/3 less than fossil fuels doing the same job (Mathias Aarre Mhlum,

2013). Figure 2 inAppendix A (2) shows the process of biomass to bioenergy featuring the

variety of bio products. At present, biomass co-firing in modern coal power plants with

efficiencies up to 45% is the most cost-effective biomass use for power generation

(International Bio-Energy Partnership, 2007).

Appendix A (2)-

Figure 2- Biomass to bioenergy

Source:http://www.colorado.edu/geolsci/courses/GEOL3520/Biomass.pdf
http://www.colorado.edu/geolsci/courses/GEOL3520/Biomass.pdfhttp://www.colorado.edu/geolsci/courses/GEOL3520/Biomass.pdfhttp://www.colorado.edu/geolsci/courses/GEOL3520/Biomass.pdfhttp://www.colorado.edu/geolsci/courses/GEOL3520/Biomass.pdf


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Appendix B-

Figure 3- Labelled diagram of wind turbine

Source:https://reader012.{domain}/reader012/html5/0813/5b70d2efca1f4/5b70d2f2b30a0.jpg
http://www.greenribbonschools.org/activity/1098/1328040112.jpghttp://www.greenribbonschools.org/activity/1098/1328040112.jpghttp://www.greenribbonschools.org/activity/1098/1328040112.jpghttp://www.greenribbonschools.org/activity/1098/1328040112.jpg


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Physics of Solar energySunlight is composed of photons, which can be depicted as bundles of energy (the amount

of energy in a photon being proportional to the frequency of its light). When photons hit a

solar cell, the majority of the photons either reflect or are absorbed. When a photon is

absorbed, its energy is transferred to the semiconductor specifically, to an electron in an

atom of the cell. If enough energy is transferred, the electron can escape from its initial

position associated with the atom. In the process the electron causes a hole to form and

each proton with enough energy stored will normally free one electron and on hole. Modern

photovoltaic cells are commonly grouped together into a frame, called a photovoltaicmodule (i.e. a solar panel), and can be grouped into large solar arrays capable of producing

large amounts of electricity. The cells themselves are made of semiconductor materials such

as silicon. In what is known as the Photoelectric Effect, photons of light from the suns

electromagnetic radiation strike the surface of the photovoltaic cell and if the frequency and

energy of these photons is adequately high, they will knock electrons loose from the

semiconductor material (jjwalter, 2012). This is shown in the diagram Figure 4 in

Appendix C.

The minimum energy which must be transferred by a photon to the material for this to

happen is known as the work function of the material (a value which differs depending on

the material used) and this also represents the minimum frequency, or threshold frequency,

of the photon needed. Photons with adequate amounts of energy interact with the electrons

in the material in a one to one ratio; therefore a single photon causes the emission of a

single electron, with any surplus energy of the photon above the work function contributing

to the kinetic energy of the emitted electron. The resulting free-flowing electrons make up

the electrical current produced by the photovoltaic cell.

However, these electrons will not simply move (i.e. develop electricity) on their own

without an outside force to affect them. This is where an electric field comes into the picture.

In a photovoltaic cell made of silicon for example, two types of silicon are used. Each type of

silicon comprises of specific impurities, which modify its structure and behaviour. Theprocess of adding these impurities is known as doping. The top (exterior) layer is made up

of N-type silicon, which is doped with phosphorous atoms to produce a type of silicon with

an overall negative charge (hence the name N-type). The bottom (second) layer is made up

of P-type silicon which is doped with boron atoms, which gives the silicon an overall

positive charge (thus P-type). The difference in charge between the two layers of silicon

now creates an electric field which pushes and pulls the free electrons ejected from the N-

type silicon towards the layer of P-type silicon (second layer) (jjwalter, 2012). This is

shown in the diagram Figure 5 inAppendix C (1) and Figure 6 inAppendix C (2).


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Physics of Photomagnetic EffectAccording to the article Solar power without solar cells, the photomagnetic effect is a

theoretical quantum mechanical effect discovered by researchers Samuel L. Oliveira and

Stephen C. Rand at the University of Michigan (2007-2011). It is believed by them that there

is a possibility that solar power can be generated without solar cells. Their idea of an

optical battery, which would involve performing the energy conversion inside insulators

instead of semiconductors, could make a cheap alternative source of energy than existingsolar-cells. In the conventional solar cell, electricity is generated by simple charge

separation. The semiconductor absorbs a photon of sunlight, knocking a negative electron

into the materials conduction energy band thus leaving a positive hole in its p lace. With the

two charges separated, a voltage is produced from which the power can be drawn. But,

researchers (Samuel L. Oliveira and Stephen C. Rand) have performed calculations to

predict that voltages can be generated in insulating materials, using what the researchers

say is a previously overlooked aspect of lights magnetic field.

Light is an electromagnetic wave, meaning that it has two sections an electric field and amagnetic field. In free space, the magnetic field is weaker than the electric field, almost so

weak as to be negligible. Once it enters a material, the electric field then accelerates chargeselectrons in its direction. Physicists had thought that the magnetic field would affect the

dynamics of the electrons only when they approach very high "relativistic" speeds, close to

the speed of light. But Rand and Fisher have calculated that when electrons are bound to

their nuclei, as they are in insulators, the electric and magnetic dynamics of the electron

become linked, letting energy pass from one to the other. The result is that when light

shines on an insulator, the magnetic field alone can shift electrons in the direction of the

light, creating a polarization of charge. This acts like an optical capacitor, which can be

tapped for electricity perhaps at efficiencies of around 10%. (Jon Cartwright, 2011).


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Physics of nanocrystalsCareful spectroscopic measurements have produced a precise assessment of the efficiency

of carrier multiplication, which is a process where a single photon of light creates more

than one electron-hole pair in a semiconductor quantum dot. A quantum dot is only 10s of

atoms across and spatially limits the electron-hole pairs, thus leading to verified

quantitatively in current photovoltaic devices made out of lead selenide quantum dots. The

new devices have enough potential for improvements compared to the current photovoltaic

cell. In carrier multiplication (CM), a single photon from sunlight creates two electricalcurrent, therefore potentially boosting the current in a solar cell. In these studies, CM has

been observed in photocurrent of real solar cells based on PbSe quantum dots, with

efficiencies that match those observed in spectroscopic studies (US Department of Energy,

2011). This is shown in the diagram below:


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Appendix C-

Figure 4- The Photoelectric Effect

Source:http://swcphysics30.wordpress.com/2012/06/09/the-photoelectric-effect-and-

power-generation-from-solar-energy/

Appendix C (1)-

Figure 5- Layers of N- and P- type silicon
http://swcphysics30.wordpress.com/2012/06/09/the-photoelectric-effect-and-power-generation-from-solar-energy/http://swcphysics30.wordpress.com/2012/06/09/the-photoelectric-effect-and-power-generation-from-solar-energy/http://swcphysics30.wordpress.com/2012/06/09/the-photoelectric-effect-and-power-generation-from-solar-energy/http://swcphysics30.wordpress.com/2012/06/09/the-photoelectric-effect-and-power-generation-from-solar-energy/http://swcphysics30.wordpress.com/2012/06/09/the-photoelectric-effect-and-power-generation-from-solar-energy/http://swcphysics30.wordpress.com/2012/06/09/the-photoelectric-effect-and-power-generation-from-solar-energy/


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Appendix C (2)-

Figure 6- Conventional solar cell physics and diagrams

The p-n junction

Doping a semiconductor with impurities produces regions with greater or lesser

affinities for electrons.

When the two types of materials come into contact, band misalignments and

different carrier densities on either side of junction occur.

Photovoltaic idea

When an electron-hole pair are excited near a p-n junction, they may separate in the field.

If they have no place to go, they pile up on either side until the voltage opposes the built-in

voltage due to impurities.


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Appendix C (3)-

Figure 7- Constraints on novel solar cells/panels

Due to the cost of the balance of systems, a solar cell of zero cost must exhibit

efficiency greater than about 15% to be financially practical.

Must be deployable in a large area.

Must have a useful lifetime greater than 10 years or more

Appendix D-

Figure 8- Solar Panel Efficiency

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SUBSTITUTE


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Bibliography Andrew Miskelly, 2014. Wind Energy. [Online]

Available at: http://energy.anero.id.au/wind-energy

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regionLGA=REGION&regionASGS=REGION

[Accessed 27 10 2014].

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alternative-energy.htm

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Ratch Australian Corporation, 2014. Wind Energy Generation Wind Hill Wind Farm. [Online]

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The Future of Innisfail's Energy (GOOD)