The document discusses various renewable and non-renewable energy sources. It provides information on how different energy sources work, including fossil fuels like coal, oil and gas, as well as renewable sources like solar, wind, hydroelectric, geothermal, and nuclear. It discusses the basic processes of energy conversion, emissions, costs and environmental impacts of each energy source. Sankey diagrams are also introduced to illustrate energy transfers from different fuel sources.

1. Energy sources8.1

2. World energy Sources
In 2006, about 18% of
global final energy
consumption came
from renewables.
How much progress
have we made?
Image from wikipedia

3. World energy Sources
Who uses the most?
What questions do you need to ask to explore this in detail?

4. World energy Sources
 Does it matter where you are geographically?

5. Energy types
 Kinetic
 Potential
 Thermal
 Sound
 Light (Electromagnetic)
 Electrical
 Magnetic
 Nuclear
 Chemical

6. Energy degradation
 Every time energy is converted from
one form to another thermal energy
will be lost
 Conversion of energy into work is a
cyclical process
 Energy transferred to surroundings is
no longer able to do useful work

7. Energy density of fuel
 Energy density is the amount of energy stored
in a given system or region of space per unit
volume or per unit mass
 J/kg
 Need to be able to do calculations

8. Energy conversion of typical fuels
Firewood 16 MJ/kg
Brown coal 9 MJ/kg
Black coal (low quality) 13-20 MJ/kg
Black coal 24-30 MJ/kg
Natural Gas 39 MJ/m3
Crude Oil 45-46 MJ/kg
Uranium* - in light water reactor 500,000 MJ/kg

9. Advantage Disadvantage
Oil widely accepted in manufacturing ,
relatively cheap and high efficiency
CO2 emission, greenhouse effect.
Gas high efficiency expensive to transport and store, CH4
contributes to greenhouse effect.
Coal widely accepted in manufacturing,
cheapest among the three non-
renewable energy source
low efficiency, air pollution, CO2 and CO
emission, greenhouse effect.
Solar easy to get sun light, renewable energy
source
expensive to use solar panel and grid, unstable
in modern due to the changeable weather
Wind easy to get wind, renewable energy
source
noise, spoil scenery, expensive maintaining fees
Biofuel clean, renewable energy source expensive in refining process
Geothermal stable, renewable energy source expensive to build, the technology has not been
very mature yet
Hydropower functional. very useful to avoid flooding
in some countries, renewable
energy source
very expensive to build, expensive to maintain,
drought, harm the river eco-system

10. Sankey diagrams
 A Sankey diagram show energy transfers in a
scale diagram
 Arrowheads are in proportion to value
 You need to be able to draw these from data

11. Sankey diagrams
 For fossil fuel power stations

12. Sankey diagrams-nuclear

13. Sankey diagrams- solar

14. Sankey diagrams- hydroelectric

15. Sankey diagrams- wind

16. What is renewable?
 Reusable
 Bountiful
 Short time to regenerate
 Cheap
 Life time to regenerate
 Something else?

17. History of fossil fuel
power production
 Industrialisation
 Higher energy consumption
 Industry near to fossil fuel deposits

18. Coal

19. Coal
Power is generated via a power plant in the following way:
 Coal and lmestone is injected into a bed furnace.
 The ash from the coal is removed from the plant and then
disposed of.
 This furnace is used to heat a large container of water.
 this water then is turned into steam and then pushed at high
speed through a turbine.
 The turbine turns a Generator.
 This generates a huge amount of electricity and is then
carried off by the substandard power grid that is often shut
off so that victoria still has its power
 The steam is then filtered in a number particulate controllers
and any remaining ash is then removed.
 A fan then blows the steam out into the atmosphere.

20. Coal-emissions
 Carbon Dioxide Coal is the largest of the Carbon
Dioxide Contribution
 Methane Most harmful of the Greenhouse Gasses
 Ashes
 Sludge
 Flue Gas
 Mercury
 Uranium
 Arsenic
 Thorium
 Assorted Heavy Metals

21. Coal-costs
 Economic
– Coal
– Plants
– Labor
– Transport
 Social
– Health
 Cancers caused
– Environmental
 Smog
 Waste Products
 Mining

22. Oil

23. Oil
How Oil Fuelled Power Station Works:
 The combustion of heavy oil turns the water in the boiler into steam
 This is then collected in the boiler drum.
 The steam is then returned to the boiler where it is superheated, dried,
and directed towards the turbines.
 As it expands, the steam spins the turbine which drives the generator.
 After leaving the turbines, the steam passes through condensers which
return it to a liquid state
 The water is pumped back into the boiler.
 This cycle is repeated.

24. Oil-emissions
 Carbon Dioxide
 Methane Most harmful of the Greenhouse Gasses
 Ashes
 Sludge
 Flue Gas
 Mercury
 Uranium
 Arsenic
 Thorium
 Assorted Heavy Metals

25. Oil-costs
Economic
 Oil
 Plants
 Labour
 Transport
Social
 Health
– Cancers caused
 Environmental
– Smog
– Waste Products
– Mining

26. Gas

27. Gas
 The combustion of natural gas turns the
water in the boiler into steam
 This is then collected in the boiler drum.
 The steam is then returned to the boiler
where it is superheated, dried, and
directed towards the turbines.

28. Gas
 As it expands, the steam spins the
turbine which drives the generator.
 After leaving the turbines, the steam
passes through condensers which return
it to a liquid state
 The water is pumped back into the boiler.
 This cycle is repeated.

29. Gas-emissions
 Carbon Dioxide
 Methane Most harmful of the Greenhouse Gasses
 Ashes
 Sludge
 Flue Gas
 Mercury
 Uranium
 Arsenic
 Thorium
 Assorted Heavy Metals

30. Gas-costs
 Economic
– Oil
– Plants
– Labour
– Transport
 Social
– Health
 Cancers caused
– Environmental
 Smog
 Waste Products
 Mining

31. Fossil fuel usage
 Why is fossil fuel use widespread?
 What is the energy density of each fossil fuel?
 What are the advantages of fossil fuel use?
 What are the disadvantages of fossil fuel use?
 What is the efficiency of fossil fuel power
stations?
 What are the environmental concerns?

32. Nuclear
 Nuclear power is term used to describe the process
that harness the energy produced in nuclear reactions.
In nuclear reactions, the atomic energy within atomic
nuclei is transformed into other forms of energy, mainly
thermal energy. This is commonly done through the
process of nuclear fission however nuclear reactions
can also be done through the process of nuclear fusion
and radioactive decay.

33. Nuclear
 Nuclear power has many applications for
current and future uses. This is because of the
large amounts of energy if transformed in these
reactions in comparison to other sources of
energy per unit mass. This makes it ideal for
nuclear marine propulsion, to generate
electricity for humanity's energy needs or even
to fuel nuclear weapons.

34. Nuclear Fission
 Nuclear Fission is a nuclear reaction where the
nucleus of an atom is split into smaller particles
producing lighter elements. The reaction is only
energetically possible (i.e. the reaction is exothermic) if
the binding energy per nucleon for the reactants is
greater than the binding energy per nucleon for the
products

35. Nuclear Fission
 The reaction is initiated by bombarding the nuclei with
neutrons. This type of nuclear reaction is used in
nuclear power plants which harness the energy to
produce electricity.

36. Nuclear
Key components
 Moderator
 Energy transfer
 Control rods
 Heat exchangers

37. Nuclear
Retractable Control Rods
 These are used to absorb free neutrons and
prevent further fission events. Control rods,
placed between the fissile uranium are
retractable to expose more uranium and speed
up the reaction or they can be injected to cover
the uranium fuel rods and slow down the
reaction.

38. Nuclear
Moderator
 A moderator is a liquid medium, usually light or heavy
water, that surrounds the uranium fuel rods in order to
slow down the free neutrons so that they can be
absorbed into uranium atoms more easily inducing
fission, speeding up the reaction. If the moderator is at
a higher temperature then usual, then the liquid
becomes less dense, thus slowing down less neutrons.

39. Nuclear
Energy transfer
Approximately 70% of the energy released from
the reaction is wasted leaving only 30%
transformed into electricity, however the energy
content is far superior to conventional sources
such as coal for an equivalent mass on the
order of 10^7 times greater. Each fission event
releases about two hundred million eV of
energy

40. Nuclear
Enrichment of uranium occurs so that the
percentage of uranium-235 is increased to 2 or
3%.
 This allows the reaction to keep its ‘critical
mass’ (the mass required to keep the chain
reaction going).
 The method used to enrich the uranium relies
on the different masses of the isotopes. This
takes many stages and is very costly.

41. Enrichment
 U3O8 is then enriched by
– Turning it to a gas
– Gas placed in room with tiny hole at high up at one
end
– Lighter 235U has higher probability of diffusing
through hole than 238U
 Perhaps 1% higher
– Repeated through many (100 +) rooms
– Concentration now high enough to use

42. Nuclear
Fuel
U238 Pu239
 The speed of the neutrons – fast moving neutrons as less likely to
become absorbed into the nuclei and thus unable to induce
reactions.
 The mass or the number of nuclei – the more nuclei there are, the
greater the chance that a neutron will get absorbed inducing
further reactions. If the mass is too small then there is a high
chance that neutrons will be lost of the surface of the ‘block’.
Critical mass refers to the minimum mass required for a chain
reaction to occur.

43. Nuclear
Safety rods are also placed into the reactor so
that the reactor can be shut down if necessary
in a matter of seconds.
 They are triggered automatically if the coolant
pressure falls because of a pipe failure for
example.

45. Nuclear Fusion
 Nuclear Fusion is a nuclear reaction where nuclei are
join together or fuse producing heavier elements. The
reaction is only energetically possible (i.e. the reaction
is exothermic) if the binding energy per nucleon for the
reactants is less than the binding energy per nucleon
for the products

46. Wind
 Rotor blades - The
blades are what captures
the energy of the wind
and act like sails do on
boats. When the wind
forces the blades to
move, it has transferred
some of its energy to the
rotor.

47. Wind
 Shaft - The wind-turbine shaft is connected to
the center of the rotor. When the rotor spins,
the shaft spins as well. In this way, the rotor
transfers its mechanical, rotational energy to
the shaft, which enters an electrical generator
on the other end.

48. Wind
 Generator -The generator uses the properties
of electromagnetic induction to produce
electrical voltage. A simple generator consists
of magnets and a conductor. The conductor is
typically a coiled wire. Inside the generator, the
shaft connects to an assembly of permanent
magnets that surrounds the coil of wire.

49. Wind
 In electromagnetic induction, if you have a
conductor surrounded by magnets, and one of
those parts is rotating relative to the other, it
induces voltage in the conductor. When the
rotor spins the shaft, the shaft spins the
assembly of magnets, generating voltage in the
coil of wire. That voltage drives electrical
current (typically alternating current, or AC
power) out through power lines for distribution.

50. Wind
 Wind power equation
P = ½ Aρv3
 At 33 mph, most large turbines generate their rated
power capacity, and at 45 mph (20 meters per second),
most large turbines shut down.

51. Wind
 There are a number of safety systems that can turn off
a turbine if wind speeds threaten the structure,
including a remarkably simple vibration sensor used in
some turbines that basically consists of a metal ball
attached to a chain, poised on a tiny pedestal.
 Probably the most commonly activated safety system
in a turbine is the "braking" system, which is triggered
by above-threshold wind speeds.

52. Pumped storage
There are a number of “pumped storage” energy
resources:
Hydroelectric plants
Tidal barrages
Wave energy
are just a few of them. They all utilise converting
potential energy into kinetic energy of water.

53. Hydroelectric


54. Hydroelectric
Water Storage in Lakes:
 The first, and probably most common method
of storing water is to damn an existing river in
order to increase it's height and thus the
potential for energy to be created.

55. Hydroelectric
Tidal Water Storage
 This is very similar to wave storage in the
Tapered wave form of storage. This system
uses the kinetic energy of the wave to raise it
up and store it so it can subsequently be ran
past turbines and generate electricity.

56. Hydroelectric
Pump Storage
 Electric energy is used to pump water up to
reservoirs so it can then be run past turbines.
pump storage is only effective as long as the
energy output of the power plant is less than is
consumed to pump the water up to the
reservoir.

57. Solar
 Solar heaters use solar collectors to harness
solar radiation and convert to heat energy.
 Water is pumped through thin copper piping
embedded in a blackened copper plate with
rear insulation. On top of this is a glass plate.
 Water is piped through and heated by the
infrared radiation.
 Examples – parabolic dish, solar furnace

58. Solar Panels
 Solar panels (arrays of photovoltaic cells) make use of
renewable energy from the sun, and are a clean and
environmentally sound means of collecting solar
energy.
 Solar panels are made by semiconductor such as
silicon. Normally, electricity can't get through
semiconductors, but when the semiconductor is heated
i.e by the sun, electricity can go through.
 When the sun shines on solar panels, the electrons are
excited and start to move along a conducting wire, this
flow of electrons generates electricity.

59. Solar
 Photovoltaic cells

60. PV Cell
 A photovoltaic cell (PV cell) is a semiconductor diode
that converts visible light into direct current (DC)
(electricity). Some PV cells can also convert infrared
(IR) or ultraviolet (UV) radiation into DC electricity.
 These cells are what convert the energy from the sun
into electricity creating this solar power energy source.
PV cells are what make up solar panels as solar
panels are many PV cells connected together.

61. Semiconductor
 Photovoltaic (PV) cells are made of special materials
called semiconductors such as silicon, which is
currently the most commonly used.
 A semiconductor is a solid material that has electrical
conductivity between that of an insulator and a
conductor. When light shines on the cell, a certain
portion of it is absorbed within the semiconductor
material. This means that the energy of the absorbed
light is transferred to the semiconductor. The energy
knocks electrons loose, allowing them to flow freely.
This free flow of electrons is what creates electricity.

62. Semiconductor
Two types of semiconductor
 p-type
 n-type
Doping silicon with a group 3 element results in
an electron deficient layer (p-type), with a
group 5 element results in an electron rich
layer (n-type).

63. Semiconductor
n-type
Electron rich therefore electron can move around
p-type
Electron moves from hole to hole
This produces a potential difference

64. Why Use Solar?
Advantages:
 Solar power is a clean energy source and so it
doesn't create any greenhouse gases and pollute
the planet.
 Solar power is a renewable energy source and so
we won't run out of it unlike for example, coal for
which there is a finite amount.
 Enables self sustainability - once the panels are
installed the system will generate its own
electricity so there will be no need to buy any fuel
etc. however there will be maintenance costs.

65. Why Use Solar?
Disadvantages
 Solar power is not as efficient as other power
sources so not as much energy can be produced
with the current technology.
 Solar power is expensive compared to other power
sources and this can discourage people from
wanting to use it as the initial installation expenses
of buying and setting up the solar panels is too
much.

66. Solar
Seasonal/regional variation is due to:
Solar constant
Earth’s distance from Sun
Altitude of Sun in sky
Length of night/day