This is a Hubble Space Telescope image of a galaxy which contains of millions of stars ….. …. And the source of the energy that causes these stars to shine as brightly as our Sun is:

Our energy future: “renewable” or not? FUSION! Our energy future (A1) Or is it?

OUR ENERGY FUTURE: “RENEWABLE” OR NOT 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: 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 I am an Honorary Senior Lecturer at the School of Physics at the University of Sydney. And I have borrowed some of the slides you will see this afternoon from several of my colleagues.

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? Fusion (A1) What is energy? (A2) Why energy is necessary to keep our 21st Century civilation running Can it also be harnessed to provide the energy our society needs? (A3) And why would we want to do so?

ENERGY AND POWER What is energy? What is power How do we measure energy & power Energy in the 21st Century Fusion (A1) What is energy? (A2) Why energy is necessary to keep our 21st Century civilation running Can it also be harnessed to provide the energy our society needs? (A3) And why would we want to do so?

What is energy? Energy is that which allows us to do work (Physics definition) Lift something up Move from A to B I’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 Why discuss fusion energy? In this talk I will (A1) explain why we need to exploit nuclear fusion as an energy source – a CLEAN energy source with plentiful fuel - nothing like uranium nuclear FISSION reactors - (A2) explain the fusion process and (A3) describe how we are about to harness fusion energy. - and do many more really exciting things

Energy and power Energy is measured in joules (Physics definition) Power is the rate at which energy is supplied or consumed – how fast we use energy Power is measured in joules per second – watts A small electric radiator consumes electricity at the rate of 1,000 joule per second – 1,000 watts or 1 kilowatt – abbreviated 1 kW Energy is also measured in kilowatt hours (kWh) A 1 kW electric radiator, when operated for 1 hour, consumes 1 kilowatt hour of electrical energy. Why discuss fusion energy? In this talk I will (A1) explain why we need to exploit nuclear fusion as an energy source – a CLEAN energy source with plentiful fuel - nothing like uranium nuclear FISSION reactors - (A2) explain the fusion process and (A3) describe how we are about to harness fusion energy.

Generating electricity: big numbers 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

Energy in the 21st Century Starting in the late18th Century humanity began using coal - and in the 20th 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 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 Why discuss fusion energy? In this talk I will (A1) explain why we need to exploit nuclear fusion as an energy source – a CLEAN energy source with plentiful fuel - nothing like uranium nuclear FISSION reactors - (A2) explain the fusion process and (A3) describe how we are about to harness fusion energy.

How important is electricity? 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, electricity Why discuss fusion energy? In this talk I will (A1) explain why we need to exploit nuclear fusion as an energy source – a CLEAN energy source with plentiful fuel - nothing like uranium nuclear FISSION reactors - (A2) explain the fusion process and (A3) describe how we are about to harness fusion energy.

THE ENERGY PROBLEM FIRST: the energy problem.

The world has real energy problems We are fast running out of oil, natural gas, (and uranium) Burning of fossil fuels generates carbon dioxide (CO2) 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) (A1) We are fast running out of oil (and natural gas and uranium) (A2 Burning of fossil fuels generates carbon dioxide (CO2) For every tonne of oil or coal used for generating energy, around THREE tonnes of CO2 are generated (A3) Per capita energy consumption increases as nations become wealthier Think about India and China

Why do we need more and more energy: standard of living

Why do we need more and more energy: standard of living World

Why do we need more and more energy: standard of living AUSTRALIA World

How long will it last? Oil ~50-100 years Natural gas ~60-100 years Coal Several hundred years Nuclear fission energy (U235 burners) 50 to ~100 years Nuclear fission energy (breeder reactors) Thousands of years Solar, wind, geothermal, tidal energy Renewable I have stated that we are running out of fuel. But how long will it last We have sufficient oil reserves to last for around 50-100 years and our natural gas reserves MAY last a little longer We have sufficient coal to last us for several centuries And, surprisingly, nuclear fission energy produced by the conventional U235 burners widely in use around the world will only provide us with energy at a reasonable cost for 50 to 100 years But nuclear fission energy produced by the so-called breeder reactors could in theory provide humanity with energy for thousands of years The renewable energy sources - solar, wind, and geothermal energy – WILL provide much of our energy in the future – but not ALL of it. In contrast, NUCLEAR FUSION ENERGY WILL LAST FOR MILLENNIA. Whoops! I’ve said the N-word. Fusion IS a nuclear process. But here nuclei fuse to produce clean energy, rather than spit apart as in a uranium-burning FISSION reactor Fusion energy Millennia

WHICH ENERGY SOURCE? FIRST: the energy problem.

Wind Wind farm near Yass

Advantages: Disadvantages: Wind is cheap 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 average

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

Solar photovoltaics

Produces electricity directly Ideal for remote locations 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 transistor

Solar Thermal

Flat plate solar collectors 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 collectors

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 tube

Electricity from large-scale solar thermal plants A way of using the sun to provide a steady supply of electricity Concentrating solar collector systems Advantages: Provides “baseload” electricity supply – to some extent Disadvantages: Cost is still rather large Unreliable baseload Parallel rays of sunlight Parabolic reflector Glass envelope Absorber tube with selective surface

A “typical” modern solar thermal plant Collector tube coated with selective absorber Sunlight Heat exchanger Tank of molten salt Reflector Heat exchanger Superheated steam to turbines

Geothermal Advantages: Disadvantages: Why isn’t Australia – pioneers in the field of fusion physics - involved in the ITER project?? 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 life

Nuclear

The pros and cons of nuclear power? Advantages: NOT a (direct) source of greenhouse gases Little non-nuclear waste and pollution Volume of nuclear waste small Relatively low-cost Disadvantages: 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 years Proliferation of nuclear weapons is a concern

YES Does nuclear have a future? Waste 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 level Fission products – the waste from the energy-generation process – are highly radioactive, but decay away to become harmless in around 1,000 years Modern reactor designs are inherently less accident-prone Thorium – 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.

Fusion energy powers the Sun The light and heat emitted by the sun comes from fusion. Fusion energy powers the Sun

What is fusion? The release of the energy stored in the nuclei of “heavy hydrogen” atoms - deuterium and tritium Well, what is it? The release of the energy stored in the nuclei of heavy hydrogen atoms – deuterium and tritium. The nuclei of most hydrogen atoms – “normal” hydrogen – contain one proton. The nuclei of deuterium atoms contain one proton PLUS ONE neutron. The nuclei of tritium atoms contain one proton PLUS TWO neutrons. 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 Hydrogen: nucleus consists of 1 proton Deuterium: nucleus consists of 1 proton and 1 neutron Tritium: nucleus consists of 1 proton and 2 neutrons 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 Most Promising Fusion Reaction In terms of exploitation as a source of energy, the most promising is the fusion of deuterium and tritium nuclei. These coalesce to form this super-nucleus, which then breaks up to give a neutron, an alpha particle – and ENERGY.

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 THERE IS NOTHING TO IT. Bang a deuterium nucleus and a tritium nucleus HARD together so they “fuse” To achieve this a mixture of deuterium and tritium gases must be heated to a very high temperature – 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 Oh! 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

Toroidal field produces greater confinement A TOKAMAK So, to trap a plasma of ions and electrons in a magnetic bottle we bend the ends around to form a doughnut-shaped magnetic bottle. (A1)A few tweaks to this simple geometry gives us a TOKAMAK

International Thermonuclear Experimental Reactor ITER – “the way” International 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) ITER, as the scholars in the audience will know, is Latin for “the way”. This sounds better than it being the acronym for “International Thermonuclear Experimental Reactor”. It is an international project to produce a prototype fusion reactor. The ITER partners the European Union Japan China the Russian Federation USA South Korea India (and possibly Brazil – and Canada, Mexico and Kazakhstan)

ITER This is what ITER will look like. Note the standard human being down below. ITER is now MORE than a drawing. Site preparation at Cadarache, near Marseille in France, has been completed, building construction is under way, and components are being fabricated all over the world. Person ITER – the next generation tokamak Design completed – construction has just commenced

SUMMARY HOW MUCH WILL WE PAY? FIRST: the energy problem.

What will clean energy cost?

The top picture in this slide compares the costs of constructing, fuelling, operating, and disposing of various kinds of power stations – a summary of a large number of studies. The two bars show the upper and lower limits of a wide range of respectable studies. Note that wind and solar voltaic systems are not cheap, coal and gas are cheap – and fusion does not look as if it will be all that expensive. The lower picture compares the “estimated” impact costs to the environment, public and worker health of various sources of electricity. The white bars give the TOTAL cost. Note the low impact of fusion compared with the others – particularly coal. 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

www.withouthotair.com 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. FIRST: the energy problem. www.withouthotair.com