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ENERGY CONVERSION MME 9617a Eric Savory www.eng.uwo.ca/people/esavory/mme9617a.htm Lecture 1 - Introduction Department of Mechanical and Material Engineering University of Western Ontario. Today’s class will cover: ● Outline of the course and course project
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ENERGY CONVERSION MME 9617a Eric Savory www.eng.uwo.ca/people/esavory/mme9617a.htm Lecture 1 - Introduction Department of Mechanical and Material Engineering University of Western Ontario
Today’s class will cover: ● Outline of the course and course project ● A brief history of energy sources and energy usage ●World population growth and energy demand ●Introduction to some present day numbers and challenges
Course Objectives ● To introduce the basic technical and economic criteria for the design of efficient energy conversion systems, including traditional as well as alternative power systems ● To discuss strategies for increased energy efficiency and more environmentally sound operation ● To assess design alternatives and selection criteria, based on long-term economic viability and overall energy management strategies
Topics ● Introduction to energy conversion ● Economic considerations in energy production ● Fuels ● Review of basic theory ● Thermal energy (e.g. heat exchangers) ● Mechanical energy (e.g. pumps, turbines) ● Heat pumps ● Solar power ● Nuclear power ● Fuel cells ● Wind and wave
Assessment The course grade will be based on term work: Assignments (30%) Term research project report and presentation (70%)
The Norfolk Broads East Anglia, England
By the 12th century, much of East Norfolk had been cleared of its woodland for fuel and building materials The first written evidence of peat digging for fuel in the Broads also dates from this time Between the 12th and 14th centuries peat digging (or turf cutting) was a major industry Peat diggings were abandoned by the 14th century because they kept filling with water. They flooded, and this man-made landscape became a wetland, rich in wildlife. Now it is a major tourist and vacation area ….
Electricity Coal
Those are the main energy sources but what are they used for ? Transportation
World population growth and energy demand
? World population (1,000s) Likely to peak at 10 - 16 bn
Are there limits? Science, 162, 1243-1248 “The Population Bomb”
100 1,000 10,000 100,000 Annual income per capita $ US
Percentage shares of world population, world GDP* andworld commercial energy consumption for selected countries * GDP – Gross Domestic Product
Carbon emission factors from energy use • CO2 = Pop x (GDP / pop) x (Btu / GDP) • x (CO2 / Btu) – Seq • GDP / pop represents standard of living • Btu / pop represents energy intensity • CO2 / pop represents carbon intensity • Seq accounts for sequestered CO2 * British Thermal Unit - defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit. Melting a pound of ice at 32 °F requires 143 BTU.
BP Statistical Review of World Energy (2000) Edmonds J, Energy Policy 23, 4 – 5 (1995)
21st century trends • Increase in population leads to increasing demand for energy • Interest in developing local energy resources grows • Environmental and health concerns increase on all scales • Increased electrification • Infrastructure security concerns increase
The numbers are huge ! • Population 6,000,000,000 • Land area 58,000,000 sq miles • Population density 100+ people / sq mile • Annual energy consumption 400 Quads • oil equivalent 72,000,000,000 bbl • coal equivalent 14,400,000,000 tonnes • Registered car and trucks 700,000,0000 • Electric generating capacity 3,000,000 MW • Annual steel production 650,000,000 tonnes • Annual aluminium production 20,000,000 tonnes • Annual cement production 1,500,000,000 tonnes
Progressing towards asymptotic ? • Population -6+ billion growing to 10 to 15+ billion (?) • Total primary energy – • 400 quads growing to 2000+ quads annually (1 quad = 1015 Btu) • 73 billion growing to 365+ billion bbl of oil/yr • Per capita energy per year • 10 BOE/yr-person growing to 25 BOE/yr-person • Number of cars and trucks – • 750 million now growing to 5 + billion • MW electric generating capacity - • 3.5 million MW now growing to 15+ million MW
Other global concerns • Carbon emissions may be affecting climate • Health concerns over other emissions are growing • Global fossil energy resources are not uniformly distributed
Solutions: Find alternatives to oil Solar energy etc Transport energy as energy, not as mass Nanotechnology local energy storage (e.g. 100 kW) High voltage long distance transmission (100s GW rather than 1GW) 2003 TOP 10 GLOBAL CONCERNS 2050 * http://cohesion.rice.edu/ NaturalSciences/Smalley/emplibrary/ 120204%20MRS%20Boston.pdf
Total primary power required For IPCC BAU scenario Energy sources & demand M I Hoffert et al, Nature, 395, 881 – 4 (1998) WRE = Wigley, Richels and Edmonds, ppmv of CO2. Pre - industrial level is 350 ppmv
Energy questions • Can we satisfactorily reduce emissions and remediate wastes residing in our water and air basins? • Can we offset changes being introduced by our consumption of fossil fuels? • Can we significantly reduce our dependence on imported oil? • Can nuclear, renewable, and other non-fossil energy resources be deployed quickly enough to make a difference?
End use of energy forms • Thermal • Electrical • Electromagnetic • Chemical • fuels for transportation • fuels for industrial processes • Electrochemical • Mechanical ( KE or PE ) for power
Primary energy sources • Nuclear fission and fusion • Solar radiation • Chemical reactions, e.g. combustion of fossil and biomass fuels • Gravitational forces, planetary motion, and friction ( tides, waves and wind)
Energy rate scaling • Food 250 kcal / candy bar • Average daily requirement 2000-3000 kcal / day = 100 W • Human heart 2 W • Running 500 W • 1 horsepower 750 W • 747 jet plane 250 MW • Automobile 100 kW • Space shuttle (with boosters) 14 GW • Typical electric gen. plant 1000 MW • 1 wind turbine 1-3 MW • Laptop computer 10 W • Cell phone 2 W US energy consumption per year: 3.5 TW Worldwide energy consumption per year: 15 TW
Sustainable energy technologycharacteristics • Non-depletable on a short time scale • Low impacts on natural resources - land, water, etc. across process life cycle • Accessible and well distributed – available close to demand • Emissions free –no NOx, SOx, CO2, particulates etc. • Scalable – from 1 kW to 1,000 MW • Dispatchable - for base load, peaking and distributed needs • Robust - simple, reliable, durable and safe to operate • Flexible - applications for electricity, heat, and co-gen • Competitive economically
Energy supply options • Earth based energy • Conventional fossil fuels (coal, oil, natural gas) • Unconventional fossil fuels (oil shale, tar sands) • Nuclear fission – uranium, etc. • Hydropower • Geothermal heat • Ocean based energy • Tidal • Waves • Solar based energy • Solar thermal • Photovoltaics • Wind • Biomass
Fossil and nuclear options • Fossil – oil and gas resources are depletable and maldistributed worldwide and carbon sequestration will be costly and not a permanent solution • Fissile – no carbon emissions but wastes, proliferation and safety remain as dominant public acceptance issues • Fusion – technology not ready with uncertain costs and performance
Renewable energy technologies have high sustainability index scores • Solar • Wind • Biomass • Geothermal • Hydro Costs relative to fossil fuels remain high
‘Playing by the rules’ • The Laws of thermodynamics are relevant !! • Heat and electric power are not the same • Conversion efficiency does not have a single definition • All parts of the system must work – fuel supply, fuel and energy converters, control and monitoring sub systems, and the interconnection if required
Seek collateral opportunities • Combined heat and power (co-generation) to increase resource utilization efficiency • Integrated high efficiency building designs • Hybrid energy use with distributed generation • Manufacturing processes that use less materials and energy
Energy chains • Locating a source – solar, fossil, geothermal, nuclear • Recovery and/or capture • Storage of a resource, or storage due to the intermittency of a renewable energy supply • Conversion, upgrading, refining, etc. • Storage as a refined product • Transmission and distribution • Use and re-use • Dissipation as degraded energy and/or wastes
Resource assessment • Global energy resources are not uniformly distributed and vary widely in quality • Characterization inadequate for developed countries and very poor for developing countries • Energy resource bases and energy reserves are not the same • New technology enhancements exist to significantly improve resolution and quantification of assessments • Resource assessment is under-valued and under-supported nationally and internationally
Global resources bases Estimating resource bases is highly uncertain – (i) for mineral-based resources like oil, gas, and coal – dependence on technology and has limited data. (ii) for renewables land-use and capture efficiency are critical