the energy challenge chris llewellyn smith n.
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  1. The Energy ChallengeChris Llewellyn Smith • Part A – The energy challenge • Part B – What can/must be done

  2. Energy Facts • The world uses a lot of energy – at a rate of 15.7 TW • average 2.4 kW per person [UK – 5.1 kW, Spain 4.4] • - very unevenly (use per person in USA = 2.1xUK • = 48x Bangladesh) • 2) World energy use is expected to grow 50% by 2030 • - growth necessary to lift billions of people out of poverty • 3) 80% is generated by burning fossil fuels •  climate change& debilitating pollution • - which won’t last for ever • Need more efficient use of energy (and probably a change of life style) and major new/expanded sources of clean energy - this will require fiscal measures and new technology

  3. 1.6 billion people (over 25% of the world’s population) lack electricity: Source: IEA World Energy Outlook 2006

  4. Distances travelled to collect fuel for cooking in rural Tanzania; the average load is around 20 kg Source: IEA World Energy Outlook 2006

  5. Deaths per year (1000s) caused by indoor air pollution (biomass 85% + coal 15%); total is 1.5 million – over half children under five Source: IEA World Energy Outlook 2006

  6. Annual deaths worldwide from various causes *adding coal, total is 1.5 M Source: IEA World Energy Outlook 2006

  7. One example of the asymmetry of the likely effects of climate change Source: Stern Review

  8. HDI ( ~ life expectancy at birth + adult literacy & school enrolment + GNP per person at PPP) and Primary Energy Demand per person, 2002 Goal (?) To reach this goal seems need Human Development Index tonnes of oil equivalent/capita For all developing countries to reach this point, would need world energy use to double with today’s population, or increase 2.6 fold with the 8.1 billion expected in 2030 If also all developed countries came down to this point the factors would be 1.8 today, 2.4 in 2030

  9. Reaching 3 tonnes of oil equivalent (toe) per capita for everyone seems almost impossible* (completely impossible* while reducing CO2 emissions) – need to lower target*at least without a large reduction in population: there could be a Malthusian “solution” But 3 toe looks quite luxurious as a target for all – it is 77% of current UK per capita usage*, which (I think) could easily be tolerablefor Japan, Europe* 38% for USA Equity (same energy for all) without any energy increasewould require going to 46% of current UK usage per capita at current population level(23% for USA)- 35% with 8.1 billion population (18% for USA)! • Equity without lots more energy (whence?) would require changes of life style in the developed world

  10. Sources of Energy World’s primary energy supply (rounded): • 80 % - burning fossil fuels (43% oil, 32% coal, 25% natural gas) • 10% - burning combustible renewables and waste • 5% - nuclear • 5% - hydro • 0.5% - geothermal, solar, wind, . . . • NB Primary energy defined here for hydro, solar and wind as equivalent primary thermal energy electrical energy output for hydro etc is also often used, e.g. hydro ~ 2.2%

  11. Fossil Fuels are • generating debilitating pollution (300,000 coal pollution deaths pa in China; Didcot Power Station [large coal & gas fired plant near Oxford] has probably killed more people than Chernobyl) • driving potentially catastrophic climate change andwill run out sooner or later (later if we can exploit methyl hydrates) • Saudi saying “My father rode a camel. I drive a car. My son flies a plane. His son will ride a camel” • Is this true? Perhaps

  12. With With current growth, the 95 year (2100) line will be reached in: • 2068 for oil (growth 1.2% pa but growth will  decline beyond ‘Hubbert peak’) • 2049 for gas (growth 3.1% pa) • 2041 for coal (growth 4.5% pa); note – some people believe coal resource much smaller

  13. Oil Supply Note: discoveries back-dated

  14. Oil Supply Source: ASPO

  15. Fossil Fuel Use - a brief episode in the world’s history

  16. UNCONVENTIONAL OIL • Unconventional oil resources* are thought to amount to ‘at least’ 1,000 billion barrels (compared to 2,300 billion barrels of conventional oil remaining according to the USGS) • *oil sands in Canada, extra heavy oil in Venezuela, shale oil in the USA,… • generates 2% of global oil supply today → 8% by 2030? Expected increase mainly in Canada. Cost of producing synthetic crude (which is very sensitive to price of gas or other fuel used →steam injected to make bitumen flow) is currently $33/barrel (vs. a few $s/barrel in Saudi Arabia) Production of 1 barrel of crude requires 0.4 barrels of oil equivalent to produce steam

  17. Methyl Hydrates – Bane or Boon? • MHs are gases (bacterially generated methane) trapped in a matrix of water at low temperature and/or high pressure in permafrost and marine sediments (below 500m) • USGS (which thinks that 370 trillion m3 of natural gas are left) estimates that there are (2,800 – 8.5M) trillion m3 of MHs • Bane? Methane in MHs could be released by global warming; some evidence that this happened 55.5M years ago (late Paleocene) when the temperature rose by 5-8C • Boon? Potentially a huge source of energy: - Permafrost: Japanese test underway in Canada to release by drilling into porous sandstone containing MHs (release by pressure decrease) - Sea: danger of ‘boiling’ sinking ships and rigs

  18. Use of Energy • Electricity productionuses ~ 1/3 of primary energy (more in developed world; less in developing world) - this fraction could (and is likely in the future to) be higher • End Use (rounded)  25% industry  25% transport  50% built environment  31% domestic in UK (private, industrial, commercial)

  19. Source: IEA WEO. 2008 IEA Key Statistics give 2.3% of ‘Other’ (2006 data) Note that mixture of fuels used → electricityis very different in different countries e.g. coal ~ 35% in UK, ~76% in China (where hydro ~ 18%)

  20. Conclusions on Energy Challenge • Large increase in energy use expected, and needed to lift billions out of poverty • Seems (IEA World Energy Outlook) that it will require an increased use of fossil fuels • which is driving potentially catastrophic climate change* • will run out sooner or later • There is therefore an urgent need to reduce energy use (or at least curb growth), and seek cleaner ways of producing energy on a large scale • IEA: “Achieving a truly sustainable energy system will call for radical breakthroughs that alter how we produce and use energy” *Ambitious goal for 2050 - limit CO2 to twice pre-industrial level. To do this while meeting expected growth in power consumptionwould need 50% more CO2-free powerthan today’s total power • US DoE “The technology to generate this amount of emission-free power does not exist”

  21. Meeting the Energy Challenge – what can/must be done? I • Introduce fiscal measures and regulation to change behaviour (reduce consumption) and stimulate R&D (new/improved technology) • Increased investment in energy research*will be essential • *public funding down 50% globally since 1980 in real terms; world’s publicly funded energy R&D budget ~ 0.25% of energy market (which is $4 trillion a year) • Note – when considering balance of R&D funding, should bring market incentives/subsidies (designed to encourage deployment of renewables) into the picture

  22. Renewables 18% Fission Coal 6% 44.5% Fusion 1.5% Oil and gas 30% Energy subsidies (€28 bn pa) + R&D (€2 bn pa)in the EU in 2001 ~ 30 Billion Euro (per year) Source : EEA, Energy subsidies in the European Union: A brief overview, 2004. Fusion and fission are displayed separately using the IEA government-R&D data base and EURATOM 6th framework programme data

  23. Meeting the Energy Challenge II • Recognise that the solution will be a cocktail (there is no silver bullet), including Actions to improve efficiency(+ avoid use) Use of renewables where appropriate(although individually not hugely significant globally, except in principlesolar) • BUT only four sources capable in principle of meeting a really large fraction of the world’s energy needs: • Burning fossil fuels*(currently 80%) –must develop & deploy CO2 capture and storageif feasible • * remaining fossil fuels will be used • Solar- seek breakthroughs in production and storage • Nuclear fission- cannot avoid if we are serious about reducing fossil fuel burning (at least until fusion available) • Fusion - with so few options, we must develop fusion as fast as possible, even if success is not 100% certain

  24. Energy Efficiency • Production e.g. world average power plant efficiency ~ 30% → 45% (state of the art) would save 4% of anthropic carbon dioxide • Distribution– typically 10% of electricity lost* (→ 50% due to ‘non-technical losses’ in some countries: need better metering) *mostly local; not in high voltage grid • Use:- more energy efficient buildings, CHP (40% → 85-90% use of energy) where appropriate • - smart/interactive grid • - more efficient transport • - more efficient industry • Huge scopebut demand is rising faster • Note: Energy intensity (= energy/gpd) fell 1.6% pa 1990-2004 • Efficiency is a key component of the solution, but cannot meet the energy challenge on its own

  25. The Built Environment • Consumes ~ 50% of energy (transport 25% and industry 25%) • → nearly 50% of UK CO2 emissions due to constructing, maintaining, occupying buildings • Improvements in design could have a big impact • e.g. could cut energy used to heat homes by up to factor of three (but turn over of housing stock ~ 100 years) • Tools: better information, regulation, financial instruments Source: Foster and Partners. Swiss Re Tower uses 50% less energy than a conventional office building (natural ventilation & lighting…)

  26. APS Study of Building Efficiency • In USA:buildings use 40% of primary energy - • Heating and cooling: 500 GW primary energy (65% residential; 35% commercial) • Lighting: 250 GW primary energy(43% residential; 57% commercial) 22% of all US electricity (29% world-wide) • [Spain: total electricity 31 GW ~ 90 GW primary energy, thermal equivalent] • Measures on lighting: • Better use of natural light; reduce ‘over-lighting’; more efficient bulbs: • Traditional incandescent bulbs ~ 5% efficient • Compact fluorescent lights ~ 20% efficient • Detailed study: in USA, upgrading residential incandescent bulbs and ballasts and lamps in commercial buildings could save = 3% of all electricity use ( If this finding translates pro rata to UK, it would save one 1 GW power station!) • In longer term: LEDs (up to 50% efficient); R&D needed → white light + reduce cost

  27. TRANSPORT~ 25% of primary energy • Consider light vehicles • Major contributor to use of oil (passenger cars and light trucks use 63% of energy used in all transport in USA) + CO2 T • Growing rapidly e.g. IEA thinks 700 million light vehicles today → 1,400 million in 2030 (China: 9m → 100m; India: 6.5 m → 56m) • Is this possible? • Can certainly not reach US levels: for the world’s per capita petrol consumption to equal that in the USA, total petrol consumption would have to increase by almost a factor of ten Report APS Study of Potential improvements.Consider: what after the end of oil? (Biofuels, coal & gas → oil, electric, hydrogen…)

  28. Trends: Improvements: front wheel drive, engine, transmission, computer control….. 1975 – 1985 mandatory Corporate Average Fuel Economy standards improved annually, but thereafter manufactures continued to improve efficiency but built heavier, more powerful cars:

  29. Prospects for ImprovementsAPS Considers 50 mpg (US) by 2030 reasonable*(decreased weight: -10% → 6-7% fuel economy), improved efficiency, hybrids + possibly Homogeneous Charge Compression Ignition, variable compression ratios, 2/4 stroke switching….*4.7 litres/100km MIT Study: In longer term maybe Plug-in Hybrids, hydrogen (or other) fuel cells

  30. Petrol engines much less efficient than electric motors (90%), but comparison needs overall well to wheels analysis

  31. Electric vs. Petrol Pro electric:efficiency Oil well → 90% tank → 0.9 x 12.6% = 11% wheels Source → 30% electricity → 0.3 x 90% = 27% battery → 0.27 x 90% = 24% wheels Source→ ? fuel cell →≤ ? x 60% electricity → ≤?x 0.6x 90% = ? x 55% wheels Pro petrol:weight/volume Petrol 34.6 MJ/l 47.5 MJ/kg Li ion battery (today) 0.7 MJ/l 0.5 MJ/kg H at 1 atmosphere 0.009 MJ/l 143 MJ/kg H at 10,000 psi 4.7 MJ/l 143 MJ/kg Liquid hydrogen 10.1MJ/l 143 MJ/kg APS “Hydrogen fuel cell vehicles unlikely to be more than a niche product without breakthroughs…challenges are durability and cost of fuel cells, including catalysts, cost-effective on-board storage, hydrogen production and deployment and refuelling infrastructure”

  32. Hydrogen • Excites public and politicians • - no CO2 at point of use • Only helpful if no CO2 at point of production • e.g. - capture and store carbon at point of production • - produce from renewables (reduced problem of intermittency) • - produce from fission or fusion (electrolysis, or ‘catalytic • cracking’ of water at high temperature) • Usually considered for powering cars: • Excellent energy/mass ratio but energy/volume terrible • Need to compress or liquefy (uses ~ 30% of energy, and adds to weight), or absorb in light metals (big chemical challenge – being addressed by Oxford led consortium)

  33. Renewables • Could they replace a significant fraction of the 13 TW (and growing) currently provided by burning fossil fuels? • Solarcould in principle power the world – given breakthroughs in energy storage and costs (which should be sought) – see later • Hydro - already significant: could add up to 1TW thermal equivalent • Wind -up to 3 TW thermal equivalent conceivable • Burning biomass - already significant: additional 1 TW conceivable • Geothermal, tidal and wave energy - 200 GW conceivable All should be fully exploited where sensible, but excluding solar, cannot imaging more than 6 TW – huge gap as fossil fuels decline • [Conclusions are very location dependent: geothermal is a major player in Iceland, Kenya,…; the UK has 40% of Europe’s wind potential and is well placed for tidal and waves; the US south west is much better than the UK for solar; there is big hydro potential in the Congo;…]

  34. Preliminary Conclusions • Must improve efficiency – but at best will only stop growth (unless we are prepared to tolerate a very inequitable world). Needs initial investment, but can save a lot of money • Must exploit renewables to the maximum extent reasonably possible (not easy as it will put up costs) • Likely most of remaining fossil fuels will be burned. If so, carbon capture and storage is the only way to limit climate change(but will put up costs) • In the long-run, will need (a combination of): • - Large scale solar • Much more nuclear fission • Fusion

  35. Carbon Capture and Storage • In principle could capture CO2 from power stations (35% of total) and from some industrial plants (not from cars, domestic…) • Capture and storage - would add ~ $2c/kWh to cost for gas; more for coal - in both casesmuch more initially • Storage - could (when location appropriate) be in depleted gas fields, depleted oil fields, deep saline aquifers • Issues are safety and cost (capture typically reduces efficiency by 10 percentage points, e.g. 46% → 37%, 41% → 32%,..) • With current technology: capture, transmission and storage would ~ double generation cost for coal

  36. After capture, compress (>70 atmos → liquid) transmit and store (>700m):

  37. Conclusions on Carbon Capture and Storage • Mandatory if feasible and the world is serious about climate change- big potentialifsaline aquifers OK (said to be plenty in China and India) • Large scale demonstration very important • - First end-to-end CCS power station just opened in N Germany (30MW oxy-fuel add–on → steam to turbines in existing 1 GW power station) • - EU Zero Emissions Power strategy proposes 12 demonstration plants (want many, in different conditions) by 2015: needed to develop/choose technologies, and drive down cost, if there is going to be significant deployment by 2030 • Meanwhile should make all plants ‘capture ready (post-combustion or oxy-fuel) • It will require a floor for the price of carbon

  38. Solar Potential • Average flux reaching earth’s surface is 170 Wm-2,220 Wm-2 at equator, 110 Wm-2 at 50 degrees north • 170 Wm-2 on 0.5% of the world’s land surface (100% occupied!) would with 15% efficiency provide 19 TW • Photovoltaics are readily available with 15% efficiency or more, and concentrated solar power can be significantly more efficient • Photosynthesis: • Natural:energy yields are vary from30-80 GJ/hectare/year (wood) to 400-500 GJ/hectare/year (sugar cane) • 100 GJ/hectare/year corresponds to 0.3 Wm-2, or 0.2% of average solar flux at earth’s surface, so even sugar cane is only 1% efficient at producing energy. • At 0.3 Wm-2, would need 15% of world’s land surface to give 10 TW • Artificial: exciting possibility of mimicking photosynthesis in an artificial catalytic system to produce hydrogen (to power fuel cells), with efficiency of possibly 10% (and no: wasted water, fertiliser, harvesting) – should be developed

  39. Solar (non-bio) • Photovoltaics (hydrogen storage?) • Concentration (parabolic troughs, heliostats, towers) High T: • → turbines (storage: molten salts, dissociation/synthesis of ammonia, phase transitions in novel materials…) • → ‘thermal cracking’ of water to hydrogen • Challenges: new materials, fatigue… • Thermal (low T): hot water (even in UK not stupid), cooling

  40. Projected cost of photovoltaic solar power? $1/WpAC → 2.6 €-cents/kWhr in California (4.7 in Germany) - requires cost ~ cost of glass!

  41. Solar Parabolic Trough Mirrors + receivers + conventional (super) heated steam turbine. Generally solar/fossil hybrids (can be ISCC). Considerable experience (a few with heat storage). Individual systems < 80 MW.

  42. HeliostatsHeats molten salt to 565C (buffer) → steam, or air or water. May (initially at least) be hybrid (including ISCC). Pilots built, but none yet on commercial scale: 50 – 200 MW. Dish/Stirling engine Up to 750C, 20 MPa. High efficiency (30% achieved. Small (< 25 kWeach). Modular. May be hybrid. Needs mass production to drive down cost (can → Brayton turbine)

  43. Nuclear Power • Recent performance impressive– construction ~ (?) on time and (?) budget, excellent safety record, cost looks OK • New generation of reactors (AP1000, EPR) – fewer components, passive safety, less waste, lower down time and lower costs • Constraints on expansion • snail’s pace of planning permission (in UK +…) • concerns about safety • concerns about waste • proliferation risk • availability of cheap uranium

  44. Problems and limitations • Safety – biggest problem is perception (arguable that Didcot power station has killed more people than Chernobyl) • Waste – problem is volume for long term disposal US figures: Existing fleet will → 100,000 tonnes (c/f legislated capacity of Yucca mountain = 70,000 tonnes) If fleet expanded by 1.8% p.a. → 1,400,000 tonnes at end of century • Proliferation – need to limited availability of enrichment technology, and burn or contaminate fissile products

  45. Uranium Resources • . US DoE Data/Projections: Assuming 1.8% p.a. growth of world’s nuclear use Unless there is much more than thought, or we can use unconventional uranium, not long to start FBRs Will need to use thorium and/or fast breeders in ~ 50 years Need to develop now

  46. Different Fuel Cycles • Goals - reduce waste needing long-term disposal (destroy: [99.5+%?] of transuranics, and heat producing fission products [caesium, strontium]) - burn or ‘contaminate’ weapons-usable material - get more energy/(kg of uranium) • Options(some gains possible from improved burn-up in once through reactors; as in all thermal power plants, higher temperature → more energy/kg of fuel) • Recycle in conventional reactors – can get ~2 times energy/kg + reduce waste volume by factor 2 or 3 (note: increase proliferation risk + short-term risk from waste streams) • Fast breeders [Mixed economy: conventional reactors + burn waste by having some FBRs or accelerator based waste burners]

  47. Plutonium Fast Breeders • In natural uranium, only 235U (0.7%) is fissile, but can make fissile Plutonium from the other 99.3% 238U + n → 239Np → 239Pu fertile fissile • order 60 times more energy/kg of U • more expensive (and not quite so safe + large plutonium inventory), but far less waste → storage Potential problem slow ramp up* (1 reactor→ 2 takes ~ 10 years) * Based on figures from Paul Howarth: 1 GWe FBR needs stockpile of ~ 30 tonnes Pu to operate ~ 12 years [30 tonnes of Pu is output of a 1 GWe LWR for ~ 140 years] After 12 years → 30t Pu to refuel + 30t Pu to start another

  48. Thorium • Thorium is more abundant than Uranium* and 100% can be burned (generating less waste than Uranium), using 232Th + n → 233Th → 232Pa → U233 fertilefissile Thermal neutrons OK, but then to avoid poisoning need continuous reprocessing → molten salts * accessible 232Th resource seems (??) to be over 4 Mt, vs. 0.1 Mt for 235U (if total accessible U resource is 16 Mt) • Need Pu or highly enriched U core (→ large number ofneutrons)or neutrons from accelerator driven spallation source* in order to get started Relatively rapid ramp up but long doubling time (?) * avoids having a near critical system, but economics suggest AD system’s best potential is for actinide burning