Which Energy for the Future?

Transcription

1 Which Energy for the Future? Carlo Rubbia CERN, Geneva, Switzerland CIEMAT, Madrid, Spain Madrid, February

2 The future of energy The forecasts over the next several decades of leading Agencies, like for instance the International Energy Agency, foresee agreement with a continued increase of energy at the rate of 2%/year, for a population increment of 1%/year. The dominance of fossils is expected to continue, with the corresponding enhanced greenhouse emissions, a stable nuclear energy production and a rather small increase of renewables. In 2005 the fossil fuel dependence was 81% for the world, 82% for China and 88% for the United States. No doubt our appetite for power grows with time, even if 1% per year decline in energy intensity may be assumed, based on the historic trend. Madrid, Feb 2008 Slide# : 2

3 2004 fuel shares Total world s PV = % of time = nuclear energy of 1 EPR of new generation Totals Renewables New Renew. Madrid, Feb 2008 Slide# : 3

4 Primary total world s Energy Today the energy consumption is equivalent to the one of an engine with an average power of 15 TWatt Predictions of business as usual indicate that energy may increase to as much as TWatt by 2050 Madrid, Feb 2008 Slide# : 4

5 Fossil reserves are huge and readily available Oil and Natural gas are expected to reach their limits sooner or later, due to an increase of consumption and the progressive reduction of easily available resources. However there is plenty of cheap and readily available Coal. The known reserves are about 5000 Gton and it could be up to Gton if also less noble forms of supply are used. Coal or Shales can for instance be easily converted into liquids (Methanol, Ethanol and so on) to replace Oil and into a gas (Syngas and so on) to replace Natural Gas. There are sufficient amounts of Carbon in its various forms to produce cheap and abundant energy for many centuries at several times the present level of energy consumption. There is no technical reason why, once reduced the local pollutions, this huge amounts of Coal may not be eventually fully burnt Madrid, Feb 2008 Slide# : 5

6 A new term in the balance: antropogenic forcing It is therefore because of our conviction in the antropogenic gas emissions and of their expected, dramatic effects on the climate of earth that our reason may justify curbing an otherwise smoothly growing combustion of fossils. The whole Industrial Revolution has been driven by cheap and abundant fossil energies. Any major change of such a magnitude requires an immense innovation in the habits of us all. Even if very serious and compelling, is very difficult to implement a carbon free option without major oppositions. Madrid, Feb 2008 Slide# : 6

7 -1.3 GtC +1.1 GtC -2.0 GtC 1 ppmv CO 2 = 2.1 GtC Antropogenic effects Fossils -2.0 GtC into Carbonates Madrid, Feb 2008 Slide# : 7

8 Antropogenic effects of CO2 emissions In the CO2 emissions, an important multiplying effect takes place; The climatic effect of the combustion of a given amount of fossil fuel produces one hundred times greater energy capture due to the incremental trapped solar radiation (if we burn 1 with a fossil, the induced, integrated solar heat increment is >100!). Fossils represents a business of some 6 millions of millions $/year. A major shift in the today s world s energy sources, externally driven by environmental considerations like the concerns for global warming, even if they are of very serious and compelling nature, is very difficult to implement without major oppositions. Technological improvements will, no doubt, introduce other forms of energy: but the planet will continue notwithstanding to burn fossils for a long time to come,especially in those parts of the planet where the technological change is the slowest. What are the consequences of a cumulative emission of 5000 GtC even for a constant fraction remaining in the atmosphere (0.6)? Madrid, Feb 2008 Slide# : 8

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12 Assume that a major fraction of fossils are burnt. 1 2 The maxima of CO 2 concentration ( 4 x the present level) are reached somewhere between 400 and 800 years from today, only slightly dependent on the distribution. At 2000 years from today the concentration is still twice the present level. Note that the climatic forcing in not driven only by CO2, (60%). There are other gases: Methane (20%), tropospheric Ozone (20%) Nitrous oxide (5%), black Carbon (10%). These effects are reduced by the presence Sulfate Aerosols (-25%). Madrid, Feb 2008 Slide# : 12

13 How long will CO2 last in the biosphere? The idea that anthropogenic CO2 release affects the climate of the earth for hundreds of thousands of years has not reached general public awareness. This misconception is still widespread also in the scientific community. The long-term consequences of fossil fuel CO2 release have not yet reached the same level of public awareness and concern as the production of long-lived nuclear waste, for example Plutonium lifetime is 26 kyr. Fossil carbon survival : After years 17-33% At years 10 15% At years 7% The mean lifetime of fossil CO2 is about kyr. Madrid, Feb 2008 Slide# : 13

14 Therefore A mean atmospheric lifetime of order 10 4 years is in stark contrast with the popular perception of several hundred year lifetime for atmospheric CO2. The 300 year simplification misses the immense longevity of the tail on the CO2 lifetime, an hence its interaction with major ice sheets, ocean methane clathrate deposits, and future glacial/interglacial cycles. Caldeira, K., and M. E. Wickett (2005), J. Geophys. Res., 110, C09S04. Madrid, Feb 2008 Archer, D. (2005), J. Geophys. Res., 110, C09S05 Slide# : 14

15 Response of Greenland Ice Sheet to climatic forcing Greenland ice sheet melt area has increased on average by 16% from 1979 to 2002, at a rate of about 0.7%/year. Madrid, Feb 2008 Slide# : 15

16 A few disturbing facts from Greenland last summer 552 billion tons of ice melted from the ice sheet (NASA), +15% than the average summer melt, beating 2005's record. The surface ice loss was +12% more than in 2005, nearly quadruple the amount that melted just 15 years ago. The surface area of summer sea ice floating in the Arctic was nearly 23% below the previous record. The Northwest Passage was open to navigation. NASA data are showing an unusually thin sea ice. Combining the shrinking area covered by sea ice with the new thinness of the remaining ice, the volume of ice is half of 2004's total. Surface temperatures in the Arctic Ocean this summer were the highest in 77 years of record-keeping, in some places 5 C above normal, twice as fast as the rest of the planet. By 2020/40 the summer sea ice may be gone. The induced warming up may lead to the subsequent melt of the ice sheet. Madrid, Feb 2008 Slide# : 16

17 Rise of oceans: how large? The speed of reduction of the sea ice is growing much more rapidly than the worst predictions! Such subsequent Greenland s ice caps meltdown may indeed cause increases of the sea level between 7 and 15 meters. Madrid, Feb 2008 Slide# : 17

18 A new political determination The realization of the risks related to Climate Change has generated especially in the in the EU -but also elsewhere- the political determination (based on well founded scientific considerations) for a quick and dramatic reduction of the present emissions from fossils. Global warming and pollution are inevitable consequences of our growing population and economies. Investing in devices which conserve energy is worthwhile, but also new alternatives must be vigorously pursued with an appropriate level of investment. It is generally believed that by 2050, or even earlier, a progressive reduction to at least 1/2 the present CO2 emissions from fossils is needed, namely to 6 TWatt, leading to TWatt of carbon free supplies, or if possible, of more. WARNING: Reversing an un-interrupted fossil dominance lasted for over three centuries may not be accomplished without fierce oppositions. Madrid, Feb 2008 Slide# : 18

19 Curbing the CO2 emissions: the magnitude of the problem A huge reduction! Today about 80% of the energy produced is due to fossils, with about 6.5 GTonC emitted every year. Predictions of business as usual indicate that it may continue to increase to as much as 15 GTonC/year by Madrid, Feb 2008 Slide# : 19

20 Have the cake and eat it : CO2 sequestration? Already used by the oil industry, at the level of few million tons/y (Sleipner Field, Statoil,NO) Considerable room is apparently available, especially in deep saline acquifers (sufficient for many decades of coal consumption) It requires a distributed pipeline network for CO 2 disposal, roughly doubling the cost of electricity. Several drawbacks, which may imply considerable R & D, with huge investments if they were to have a sizeable effect: Volumes of CO 2 to be sequestrated are huge. For instance a single 1 GWe power station produces every year 11 million tons of CO 2 Sequestration does not mean elimination and eventually most of such a gas may have eventually to be re-emitted in the atmosphere Safety due to accidental leaks of such a large amounts of CO 2, is critical. At concentrations >10% CO 2 is lethal and produces death in less than 4 minutes Madrid, Feb 2008 Slide# : 20

21 A few numbers on nuclear power. In order to produce with ordinary reactors 12 TWatt i.e. 1/3 of the carbon free primary energy, we would need to build for instance about 5000 nuclear reactors each of 1 Gwatt(e), 80% efficiency and a nominal lifetime of 30 years, slightly less than one new 1 GWatt reactor every two days. A serious evaluation of the costs and critical issues related to proliferation especially in the developing countries and the security of long-term waste disposal should be carried out when facing these numbers in a long-time perspective. A New Nuclear, but on a longer timetable and with due consideration for its problems will necessarily require different fuel, breeding, incineration of the long lived waste and a new reprocessing with a closed fuel cycle preferably based on Thorium or maybe Fusion. Madrid, Feb 2008 Slide# : 21

22 Energy from renewables? If we want to produce the remaining 12 TWatt with the traditional renewables, wind, geothermal, biomass and PV, we are confronted with similarly unrealistic numbers. The image is clear: the energy needs of our planet by 2050 are much too large to be achieved by a generalised mix of the presently indicated sources. There is, however, a new Solar option which is ready and that can provide the required energetic deficit of 10 to 20 TWatt, enough to limit the dreaded risks related to climate change. The yearly energetic yield of solar energy in the sun-belt is equivalent to a thickness of 25 cm of oil. A 15 TWatt of primary energy supplied by the Sun, corresponds to only about 0.1 percent of the surface of all sunny, desertic areas, namely about 200 x 200 km 2! Madrid, Feb 2008 Slide# : 22

23 New energies: which ones? Energy from fossils is not for ever: furthermore it is likely to be prematurely curbed by the emergence of serious and uncontrollable climatic changes. Time has come to seriously consider other sources of energy curbing climatic changes, without which mankind may be heading for a disaster. Only two natural resources have the capability of a long term energetic survival of mankind: 1.Solar energy. The world s primary energetic consumption is only 1/10000 of the one available on the surface of Earth in sunny countries. Solar energy may be either used directly as heat or PV or indirectly through hydro, wind, biomass and so on. If adequately exploited, solar energy may provide enough energy for future mankind. A new method is CSP (Concentrating solar power) 2.A new nuclear energy. Energy is produced whenever a light nucleus is undergoing fusion or whenever a heavy nucleus is undergoing fission. Practical examples are natural Uranium (U-238) or Thorium (fission) and Lithium (fusion) both adequate for many thousand of years at several times the present energy consumption. A new method is the so called Energy Amplifier. This nuclear energy is not today s Nuclear and this solar energy is not today s Solar. Completely new technologies must be developed. Madrid, Feb 2008 Slide# : 23

24 Biomass Geothermal Wind Hydropower Typical Yield 1 GWh el /km²/y 1 GWh el /km²/y 30 GWh el /km²/y 30 GWh el /km²/y 890 TWh el /y 750 TWh el /y 1700 TWh el /y 1090 TWh el /y Economic potentials Demand of electric power: Typical yield CSP, PV 250 GWh el /km²/y» TWh/y Europe + Desert 2050» TWh/y world-wide 2050 Economic potentials > TWh el /y Madrid, Feb 2008 Slide# : 24 Gerhard Knies, ISES-Rome CSP WS 2007

25 Solar energy in the sunbelt (210 x 210 km² = 0.13% of deserts) is receiving yearly averaged solar energy equal to global energy consumption (15 TW x year) Gerhard Knies, ISES-Rome CSP WS 2007 Where is the energy problem? High efficiency conversion of CSP solar into high temperature heat ( C) The great transformation from fossils to solar Madrid, Feb 2008 Slide# : 25

26 Concentrating solar energy: The earliest ideas According to the tradition, Archimedes destroyed the Roman fleet at the siege of Syracuse in 213 BC by the application of directed solar radiant heat concentrating sufficient energy to ignite wood at 50 m. The first solar facility to produce electricity was installed in 1912 by Shuman in Maady, Egypt. The parabolic mirror trough concentrates sunrays on a line focus in which a tube was situated containing water that was brought to evaporation. It produced 55 kwatt of electric power. Madrid, Feb 2008 Slide# : 26

27 Principle of modern CSP Madrid, Feb 2008 Slide# : 27

28 The revival of Archimedes The first modern power plants were developed over 20 years ago and were based on hybrid NG-Solar operation. About 350 MWe were installed and are still operational today. No new CSP plants were developed during the last 15 years. The new plants now under construction are instead pure solar unit with energy storage to cover the variability of the solar flux 1) Thermal storage 2) No water cooling 3) Ultimate goal:desertic sunny areas + HVDC electricity transport Madrid, Feb 2008 Slide# : 28

29 CSP modern power plant Utility scale plant with conventional power block for centralized production full load hours using thermal storage Firm, dispatchable peak power w/o need of back-up capacity in the electric system LECs today: ct/kwh, future: 5-10 ct/kwh Madrid, Feb 2008 Slide# : 29

30 The storage of energy: an analogy with hydropower Indeed any primary main form of energy, in order to be realistically capable to counteract fossils and their emissions must be available whenever it is needed by the user and not according to the variability of the source. It is possible to insure the continuity of utilisation of CSP plant with the addition of a thermal liquid storage, in the form of a cheap molten salt. Purely thermal is normally stored only daily, with smaller volumes for given power Dual container of molten salt Thermal storage process is very efficient (less than 1% loss per day). Madrid, Feb 2008 Slide# : 30

31 Financial considerations in favour of CSP Far from today s PV, CSP is the cheapest source of renewable solar power. The levelized energy cost (LEC) for the current plants in California is US /kwh. The Spanish law setting the energy to the grid for CSP at 18 /kwh plus market price is an important incentive, since, at this rate, CSP, unlike today s PV can be operated profitably on purely private funding. Experts agree that costs can be reduced to 4-6 /kwh if the peak power capacity is expanded in the next 10/15 years to 5-20 GWatt. Likewise the (a)world Bank, (b)the US-DOE and (c) the International Energy Agency (IEA) all predict CSP s will drop below 6 /kwh by They all agree that CSP is the most economical way to generate electricity from solar energy. On the contrary of fossils and Uranium, costs for CSP electricity production in the future are well predictable. Once the plant has been paid off, like with hydro, the operating costs remain very small, of the order of 3 US /kwh. Madrid, Feb 2008 Slide# : 31

32 The leading role of CSP in Spain: June 2006 About 1.5 GWe to be installed Madrid, Feb 2008 Slide# : 32

33 Plataforma Solar Sanlucar la Mayor (PSSM) 300 MW 1200 Mio Investment 800 hectar homes Avoids annually t of CO2 Madrid, Feb 2008 Slide# : 33

34 High Potential for CSP in the South West of USA Huge power demand meets excellent solar resource Potential of identifiable areas: 200 GW generation capacity 470 TWh electricity per year (» 17% of U.S consumption) (Source: NREL) Madrid, Feb 2008 Slide# : 34

35 Generating Capacity 64 MW (Nominal) 357,200 m2 of Solar Field Annual Production > 130,000 MWh Construction in Less than 18 months, 1.6 million man-hours Capital investment : 250 Millions USD Nevada Solar 1 (2007) Madrid, Feb 2008 Slide# : 35

36 CSP Pan European Forecast for The planned EURO-MED electricity interconnection permits to produce from the Sahara large amounts of solar electricity toward the Pan- European network. Transport of electricity from far regions to central Europe is both economically and technically feasible. Year Transfer Capacity GW 2 x 5 8 x 5 14 x 5 20 x 5 Electricity Transfer TWh/y Capacity Factor Turnover Billion!/y Solar power 0.60 costs 0.67 are not 0.75 the problem 0.80! Land Area CSP 15 x x x x 50 km x km HVDC Investment CSP Billion! HVDC Elec. Cost CSP !/kWh HVDC 3100 x x x x Madrid, Feb 2008 Slide# : 36 Gerhard Knies, ISES-Rome CSP WS 2007 generation transmission

37 Solar Electricity production without water? Conventional cooling methods of thermal power plants are water intensive processes. A 200 MWatt e CSP plant requires 3 x 10 6 m 3 /y of water equivalent to the consumption of a town of inhabitants. Solar plants (troughs and towers) are particularly effective in hot, deserted areas in several locations in the world: f.i. several areas in the Sahara are ideal for CSP with small seasonal variations. In completely arid inland areas, dry cooling is needed Madrid, Feb 2008 Slide# : 37

38 Practical examples Mechanical Draft Indirect Dry Cooling System for the 60 MWe Power Unit of the Kaneka Chemical Works (Japan) Earthquake Proof Natural Draft Towers for the Dry Cooling HELLER System of the 4 x 250 MWe Shahid Rajai PP (Iran) Madrid, Feb 2008 Slide# : 38

39 Conclusions The future of mankind is crucially dependent on availability of cheap and abundant energy. Presently only Coal is capable of many centuries of intensive use of a mankind of about billion people. BUT one must seriously consider other sources of energy, without which the planet may be heading for a disaster. Nuclear and solar are main candidates. A serious long term alternative may be a new nuclear energy without U-235 and without proliferation : Thorium fission and fusion are likely candidates, capable of supplying energy for millennia to come the difference between renewable and non renewable becoming academic. The main, now ready alternative is solar energy: particularly promising is the direct use of solar radiation in the vast, arid regions of the sun belt. In particular CSP is now rapidly advancing in several parts of the world as potentially capable to become a novel, main primary form of energy, because of it lowering cost and the ability of ensuring an effective energy storage to smooth out the time variations of the sunlight. Although innovative energies may be essential to developing countries, our technically developed society should realistically foster such a change. Madrid, Feb 2008 Slide# : 39

40 Potsdam memo: a global contract between Science and Society There is overwhelming evidence that we need to tap all sources of ingenuity and cooperation to meet the environment & development challenges of the 21st century and beyond. This implies, in particular, that the scientific community engages in a strategic alliance with the leaders, institutions and movements representing the worldwide civil society. In turn, governments, industries and private donors should commit to additional investments in the knowledge enterprise that is searching for sustainable solutions. This new contract between science and society would embrace: A multi-national innovation program on the basic needs of human beings (energy, air, water, food, health etc.) that surpasses, in many respects, the national crash programs of the past (Manhattan, Sputnik, Apollo, Green Revolution etc.). Removal of the persisting cognitive divides and barriers through a global communication system A global initiative on the advancement of sustainability in science, education and training. The best young minds need to be motivated to engage in interdisciplinary problem-solving, based on ever enhanced disciplinary excellence. Madrid, Feb 2008 Slide# : 40

41 Thank you! Madrid, Feb 2008 Slide# : 41