Presentation on theme: "1. 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."— Presentation transcript:
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 OConnor, 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 OUR ENERGY FUTURE: RENEWABLE OR NOT OUR ENERGY FUTURE: RENEWABLE OR NOT
ENERGY What is energy? Why energy is necessary to keep our 21 st Century civilization running? Why it is important think about our sources of energy? And where will it come from in the future? 4
ENERGY AND POWER What is energy? What is power How do we measure energy & power Energy in the 21 st Century 5
Energy is that which allows us to do work (Physics definition) Lift something up Move from A to B Im 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? What is energy? 6 - and do many more really exciting things
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. Energy and power 7
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 Australias installed electrical capacity ( ): 51GW Generating electricity: big numbers
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 Century
10 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 How important is electricity?
THE ENERGY PROBLEM 11
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 CO 2 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) 12 The world has real energy problems
13 Why do we need more and more energy: standard of living Why do we need more and more energy: standard of living
14 World Why do we need more and more energy: standard of living Why do we need more and more energy: standard of living
15 World AUSTRALIA Why do we need more and more energy: standard of living Why do we need more and more energy: standard of living
Oil ~ years Natural gas ~ years Coal Several hundred years Nuclear fission energy (U 235 burners) 50 to ~100 years Nuclear fission energy (breeder reactors) Thousands of years Solar, wind, geothermal, tidal energy Renewable Fusion energy Millennia 16 How long will it last?
WHICH ENERGY SOURCE? 17
18 Wind farm near Yass
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 Red line: daily average Turquoise line: half-hourly average
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 transistor
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 collectors
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 tube
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 systems
27 A typical modern solar thermal plant Sunlight Reflector Collector tube coated with selective absorber Heat exchanger Tank of molten salt Superheated steam to turbines
29 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
31 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 The pros and cons of nuclear power?
32 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. Does nuclear have a future?
Fusion energy powers the Sun 33
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 tritium What 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 34
The Most Promising Fusion Reaction 35
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 36
Toroidal field produces greater confinement A TOKAMAK 37
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) 38
ITER Person ITER – the next generation tokamak Design completed – construction has just commenced 39
SUMMARY HOW MUCH WILL WE PAY? 40
41 What will clean energy cost?
External costs: estimated impact costs to the environment, public and worker health. Prospects for fusion electricity, I. Cook et al. Fus. Eng. & Des , pp25-33,
43 THATS 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