Transcript Slide 1

ENERGY CONVERSION
ES 832a
Eric Savory
www.eng.uwo.ca/people/esavory/es832.htm
Lecture 1 - Introduction
Department of Mechanical and Material Engineering
University of Western Ontario
Today’s class will cover:
● Outline of the course
● 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
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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
Electricity
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 ….
A brief history of energy
sources and energy usage
It all started with wood and peat ……
Wood
Electricity
Coal
Oil
Nuclear
Those are the main energy sources but what are they
used for ?
Transportation
Transportation
Energy Uses have changed …
Energy consumption in the USA (1775 – 1999)
World population growth
and energy demand
World population (1,000s)
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Likely to peak at 10 - 16 bn
Are there limits?
Science, 162, 1243-1248
“The Population Bomb”
100
1,000
10,000
Annual income per capita $ US
100,000
Percentage shares of world population, world GDP* and
world commercial energy consumption for selected countries
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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.
* Organization for Economic Co-operation and Development
BP Statistical Review of
World Energy (2000)
Edmonds J, Energy Policy
23, 4 – 5 (1995)
Introduction to some present
day numbers and challenges
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 !
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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:
TOP 10 GLOBAL CONCERNS
2003
Find alternatives to oil
Solar energy etc
Transport energy as energy, not
as mass
2050
Nanotechnology  local energy
storage (e.g. 100 kW)
High voltage long distance
transmission (100s GW rather
than 1GW)
* http://cohesion.rice.edu/
NaturalSciences/Smalley/emplibrary/
120204%20MRS%20Boston.pdf
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
Total primary power required
For IPCC BAU scenario
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 nonfossil energy resources be deployed
quickly enough to make a difference?
End use of energy forms
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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
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Food
Average daily requirement
Human heart
Running
1 horsepower
747 jet plane
Automobile
Space shuttle (with boosters)
Typical electric gen. plant
1 wind turbine
Laptop computer
Cell phone
250 kcal / candy bar
2000-3000 kcal / day = 100 W
2W
500 W
750 W
250 MW
100 kW
14GW
1000 MW
1-3 MW
10 W
2W
US energy consumption per year:
Worldwide energy consumption per year:
3.5 TW
15 TW
Sustainable energy technology
characteristics
• 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 1000 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
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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
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Solar thermal
Photovoltaics
Wind
Biomass
Millions of Tons of CO2 emitted
per Quad (1015 BTU)
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
Historical energy prices
Price vs. cost vs. value
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1 litre of gasoline = $ 0.50
1 litre of gasoline without tax = $0.35
1 litre of liquid hydrogen = $0.85
1 litre of bottled water = $1.00
1 litre of milk = $1.50
1 litre of orange juice = $ 3.00
1 litre of Dom Perignon 1995 = $150.00
1 litre Ralph Lauren aftershave = $ 450.00
1 litre of Chanel #5 perfume = $ 12,000.00
Courtesy of MIT website
Next week:
Definitions of energy and the economic
considerations in energy production