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1 Our energy  fu ture:  “renewable” or not? 1 Our energy  fu ture:  “renewable” or not?

1 Our energy fu ture: “renewable” or not? - PowerPoint Presentation

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1 Our energy fu ture: “renewable” or not? - PPT Presentation

2 Presentation to the Warrawee Probus Club 24 May 2013 Dr Ian Falconer School of Physics University of Sydney Some of the slides shown in this presentation were provided by ID: 741984

000 energy nuclear fusion energy 000 fusion nuclear electricity wind power solar oil years coal reactor hot waste deuterium

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Slide1

1Slide2

Our energy

fu

ture: “renewable” or not?

2Slide3

Presentation to the Warrawee

Probus

Club

24 May 2013Dr Ian

FalconerSchool of Physics, University of Sydney Some of the slides shown in this presentation were provided by: Dr Joe Khachan, University of Sydney Professor John O’Connor, University of Newcastle

Dr John How, ITER Organization Much material for this presentation was taken from: David JC MacKay Sustainable Energy — without the hot air (2009) UIT Cambridge Manfred Lenzen (2010) “ Current State of Development of Electricity-Generating Technologies: A Literature Review” Energies 15 462-591

3

OUR ENERGY FUTURE:

“RENEWABLE” OR NOTSlide4

ENERGY

What is energy?Why energy is necessary to keep our 21st

Century civilization

running?Why it is important think about our sources of energy? And where will it come from in the future?

4Slide5

ENERGY AND POWER

What is energy? What is power

How do we measure energy & power Energy in the 21st Century

5Slide6

Energy is that which allows us to do work

(Physics definition)

Lift something up

Move from A to BI’m lifting this weight from the energy I get from the food I eat Over the past 200-odd years in particular humanity has used the energy stored in coal and oil to extend the work we do beyond that we are capable of using muscle energy alone

What is energy?

6

- and do many more really exciting thingsSlide7

Energy is measured in

joules

(Physics definition)Power is the rate at which energy is supplied or

consumed – how fast we use energyPower is measured in joules per second – wattsA small electric radiator consumes electricity at the rate of 1,000 joule per second – 1,000 watts or 1 kilowatt – abbreviated 1 kWEnergy is also measured in kilowatt hours (kWh)

A 1 kW electric radiator, when operated for 1 hour,

consumes 1 kilowatt hour of electrical energy. Energy and power

7Slide8

8

Liddell power station (Muswellbrook)

4 x 500 MW generators (steam turbine alternators)

Total installed capacity: 2 GW

1 megawatt (1 MW) = 1,000 kW = 1,000,000 watt

1 gigawatt (1 GW) = 1,000,000 kW = 1,000,000,000 watt

Australia’s installed electrical capacity (2008-2009): 51GW

G

enerating electricity: big numbersSlide9

Starting in the late18th Century humanity began using coal - and

in the 20

th

Century, oil – to extend what could be done by muscle power alone.

This required the development of many ingenious bits of machinery to replace muscle power - and do much more

9

Mechanical gadgets

Food mixers, electric drills, vacuum cleaners, washing machines – all sorts of

labour-saving

devices

Transport

Electric trains, cars, aircraft, giant and fast cargo ships

Heating and cooling

Home heating, air conditioners, refrigerators and freezers

Communication

Radio, phones, TV, the internet

Energy in the 21

st

CenturySlide10

10

VERY

Primary energy sources – the ultimate source of our energy:

Coal, oil, gas, wind, the sun, uranium,

thorium, and

– for fusion – deuterium, and lithium

Secondary energy sources – the energy we use directly:

Coal, oil, gas, hydrogen, electricityHow important is electricity?Slide11

THE ENERGY PROBLEM

11Slide12

We are fast running out of oil, natural gas, (and uranium)

Burning of fossil fuels generates carbon dioxide (CO

2

)

For every tonne of oil or coal used for generating energy, around THREE tonnes of CO2 are generated Per capita energy consumption increases as nations become wealthier

Think about India and China For these reasons, we URGENTLY need an energy source to replace fossil fuels (and it must be “portable” - like petrol – so it can be used in cars and trucks)

12The world has real energy problemsSlide13

13

Why do we need more and more energy:

standard of livingSlide14

14

World

Why do we need more and more energy:

standard of livingSlide15

15

World

AUSTRALIA

Why do we need more and more energy:

standard of livingSlide16

Oil ~50-100 years

Natural gas ~60-100 years

Coal Several hundred years

Nuclear fission energy (U235

burners) 50 to ~100 yearsNuclear fission energy (breeder reactors) Thousands of years Solar, wind, geothermal, tidal energy Renewable

Fusion energy Millennia

16

How long will it last?Slide17

WHICH ENERGY SOURCE?

17Slide18

18

Wind

Wind farm near YassSlide19

19

Advantages

:

Wind is cheap

Disadvantages:

Wind is not a steady source of electricity: wind speed is highly variable

Suitable (low cost) sites are limited

Cairngorm mean wind speed in metres per second, during six months of 2006. Red line: daily average Turquoise line: half-hourly averageSlide20

20

Installed wind generating capacity in Australia: 2.6 GW (2012)Slide21

21

Solar

photovoltaicsSlide22

22

Advantages:

Produces electricity directly

Ideal for remote locations

Disadvantages:

Output depends on instantaneous amount of sunlight falling on surface

Output depends on time of day (very much) cloud cover, and season of year Cost is still rather large – but falling rapidly

A photovoltaic cell is similar in construction to a transistorSlide23

23

Solar ThermalSlide24

24

Solar hot water

“A no-brainer” David McKay, author,

Sustainable

Energy — without the hot air

Water in pipes underneath flat black plates is heated by sunlight absorbed by the black plates.The plates are coated with a selective surface – a coating that strongly absorbs the visible sunlight, but only weakly emits infra-red (heat) radiation.Maximum energy is absorbed, but not much radiated by the hot plates.

Flat plate solar collectorsSlide25

25

Evacuated tube solar collectors

A double-walled glass “tube” is evacuated – heat can only be transferred though a vacuum as radiation

The inner surface of the glass is coated with a selective absorbing material

Heat absorbed by this surface is transferred to water inside the tubeSlide26

26

Glass envelope

Parallel rays

of sunlight

Parabolic reflector

Absorber tube

with selective surface

Electricity from large-scale solar thermal plants

A way of using the sun to provide a steady supply of electricity

Advantages:

Provides “

baseload

electricity supply

– to some extent

Disadvantages:

Cost is still rather large

Unreliable

baseload

Concentrating solar collector systemsSlide27

27

A “typical” modern solar thermal plant

Sunlight

Reflector

Collector tube coated with selective absorber

Heat

exchanger

Heat

exchanger

Tank of molten salt

Superheated steam

to turbinesSlide28

28Slide29

29

Geothermal

Water pumped deep underground in to hot rock is converted to steam, which rises up another drill hole to drive an electrical generator

Advantages:

Clean, low environmental impact

Disadvantages:

Rock cools, so that the plant has a limited lifeSlide30

30

N

uclearSlide31

31

Advantages:

NOT a (direct) source of greenhouse gases

Little non-nuclear waste and pollution

Volume of nuclear waste smallRelatively low-costDisadvantages:Nuclear reactors are regarded as “unsafe” as nuclear accidents, although infrequent, have serious and widespread consequences

Radioactive waste remains a hazard for many years

* Plutonium and other “transuranics” for hundreds and thousands of years * Fission products have decayed to a “harmless level in around 1,000 yearsProliferation of nuclear weapons is a concernThe pros and cons of nuclear power?Slide32

32Waste disposal is a political problem, not a technical problem

Plutonium can be separated from other waste and be “burnt” in a reactor to produce even more nuclear energy

Most waste is low levelFission products – the waste from the energy-generation process – are highly radioactive, but decay away to become harmless in around 1,000 yearsModern reactor designs are inherently less accident-proneThorium – another “fissile” element – can also be used to fuel a reactor. Thorium cannot be used in nuclear weapons, and thorium reactors are inherently safer than uranium reactors.

Does nuclear have a future?YESSlide33

Fusion energy powers the Sun

33

FusionSlide34

Chemically these

isotopes

are the same, but the deuterium and

tritium store considerable energy in their nuclei – this is the energy that holds the nuclei together

The release of the energy stored in the nuclei of “heavy

hydrogen” atoms - deuterium and tritiumWhat is fusion?

Hydrogen: nucleus consists of

1 proton

Deuterium: nucleus consists of

1 proton

and

1 neutron

Tritium: nucleus consists of

1 proton

and

2 neutrons

34Slide35

The Most Promising Fusion Reaction

35Slide36

How do we harness fusion energy?

Bang a deuterium nucleus and a tritium nucleus

HARD together so they “fuse”

To make lots atoms move really fast a mixture of

deuterium and tritium gases must be heated

to a very high temperature if the nuclei are to “fuse”

– about 100 million degrees! Under these conditions all the atoms are ionized and form a PLASMA These high temperatures can only be achieved if the gases are contained in a “bottle” constructed from a really strong magnetic field And a high density of colliding nuclei is required if we are to get more fusion energy from the reactor

than we put into it

36Slide37

Toroidal field produces

greater confinement

A TOKAMAK

37Slide38

ITER – “the way”

I

nternational

Thermonuclear Experimental Reactor

An international project to produce a prototype fusion reactor

ITER partners

European Union

Japan China Russian Federation USA South Korea India (and possibly Brazil – and Kazakhstan)

38Slide39

ITER

Person

ITER – the next generation tokamak

Design completed – construction has just commenced

39Slide40

SUMMARY

HOW MUCH WILL WE PAY?

40Slide41

41

What will clean energy cost?Slide42

External costs:

“estimated” impact costs to the environment, public and worker health.

Prospects for fusion electricity

, I. Cook et al. Fus. Eng. & Des. 63-34, pp25-33, 2002

42Slide43

43

THAT’S ALL, FOLK

And, for further reading, I recommend:

David JC MacKay

Sustainable Energy — without the hot air

Available online as a FREE .

pdf

file from www.withouthotair.com.

www.withouthotair.com