Our High-Energy
Society
sgcolt@uaa.alaska.edu
Version 11: Sep 3, 2014
For Econ 310 fall 2014
Take-homes for energy economics
• Humans only convert energy from one form to another
– Electricity and hydrogen are energy carriers, not “sources”
– People want specific energy services at particular times
– Timing is important, especially for electricity, so storage is
a big deal
• Useful energy is lost with each conversion
• Energy services = energy + capital
– Energy is “intermediate good” with “derived demand”
– Capital is durable so energy systems change slowly
• Power (watts) is the rate at which energy is converted
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Order of topics
1.
2.
3.
4.
5.
6.
Basics – physics, energy services, units
Power = rate of energy conversion
Historical trends
Energy Intensity of the economy
[So what – energy & human welfare]
The future
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1. Basics
Optional Energy: What is It - physics?
• Ability to do Work
– (formal physics definition)
• Work = Force x distance
– Mass x acceleration x distance
– Kg x [meters / sec]/sec x meters
– Kg-m^2/sec^2
• The Newton: 1 N = 1 kg-m/sec^2
• Newton-meter = 1 kg-m^2/sec^2
• 1 Joule = 1 J = 1 Newton-meter
5
Energy + Capital = Energy Services
• We have “End Use” demands for energy
services:
– Food + mitochondria = ATP -> maintain life
– Oil + furnace = Warmth
– Electricity + speaker = Sound (speaker)
– Gasoline + automobile = Mobility (a passengerkilometer)
– Electricity + LED lamp = Light
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What Forms does it Take?
• Chemical bonds – most common form traded
in markets (why?)
– Bagel, gasoline
• Electricity – flow of electrons
• Heat / Pressure
– Warm room, hot water, steam
• Mass (E=Mc2)
– Sun, nuclear bomb, nuclear reactor
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First Law of Thermodynamics
• Energy is converted from one form to another
– (relativity: mass is a form of energy)
• Example: Your Toaster
– Natural gas ->Electricity->Heat->(toast + warmth)
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Implication of First Law:
• Electricity is not an energy source
– It’s an energy “currency”
– It’s an energy “carrier”
• Hydrogen is not an energy source
– It’s an energy currency
– It’s an energy “carrier”
• If hydrogen is the answer, where do we get
the hydrogen?
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Second Law of Thermodynamics:
• Energy is degraded with every conversion, and ends
up as low-grade heat
• Energy conversions are never 100% efficient
– and usually not even close
• Energy is lost as heat at every step
• Much harder to extract useful energy from a
room-full of low-grade heated air than from a
gas flame or electric current
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Efficiencies Vary: we
cannot say that all
lost heat is “waste” –
at least not from
economic
perspective-Incandescent light
bulb was huge
improvement over
kerosene lamp
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Measuring Energy – Common Units
• Btu – British thermal unit
– 1 lb water heated up by 1 degree f
• kWh – kilowatt hour
– Used for electricity – 1 kWh costs 10 cents in
Anchorage
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Example: Bagel
• 300 food calories =300 kcal
• x [1000 cal/kcal] = 3E+5 cal
• x [4 joules/cal] = 1.2E+6 joules
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2. Power
Power: the Rate of Energy Conversion
– Just as speed = distance per unit of time,
– Miles per hour
• Power = Energy conversion per unit of time
• Measured as Watts (W)
– 60-watt light bulb converts electricity to light (and
heat!)…
– But only while it is on!
– 1W = one joule per second
17
Power = rate of flow of energy
• Solar Energy flows through natural systems
• Energy flows through human
techno-economic systems, too
• Storage & retrieval is always costly
18
Energy flow:
Solar Radiation received at Earth’s surface:
at the average rate of about 150 watts per square meter
19
Power: other Examples
• Human (at rest)
– About 100 W (we are always on!)
• Hair dryer
–
–
–
–
1,000 W = 1 kilowatt = 1 kW (when on!)
If it is on for one hour it uses:
1 kW x 1 hour = 1 kilowatt-hour (1 kWh)
(costs 10 cents)
• Large-ish windmill
– 1 MW = 1 Megawatt = 1 million watts
• Large power plant
– 1 GW = 1 Gigawatt = 1,000 MW = 1 billion W
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Conversion Example: Jet Engine
Forms:
Chemical -> Heat ->
Motion
Power output of ONE
engine:
15 Megawatts during
take-off
60 MW for the airplane
Compare to average
electricity demand of
Anchorage: about 240
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Megawatts
Jet engine vs Sailing ship
The clipper ship
could generate
about 490
kilowatts from
the wind
=490 kW=3% of
the 747 jet
engine
Source: Smil 1994
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Optional Power: Horse vs. Hairdryer
• Horsepower = .67 kW = 670 watts
– invented by James Watt so he could charge for
steam power in a way people could understand
– Few horses can actually produce 1 hp
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3. Historical perspectives
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Pre-Industrial “Prime Movers” ~1300 BCE
Source: Smil 1994
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Beasts of burden
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50-Ton Statue on the Move
Source: Smil 1994
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Greek Tireme Galley
Source: Smil 1994
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Pre-Industrial Energy Sources
Source: Smil 1994
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Pre-Industrial Energy Sources
Source: Smil 1994
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Horizontal Waterwheel 1588
Source: Smil 1994
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Overshot Waterwheel 1770
Source: Smil 1994
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French Windmill
1770
Source: Smil 1994
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Wood: The Typical Colonial American
Farmhouse….
• Burned 30 cords of wood per year
• Needed 30 acres of woodlot
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Meanwhile, Under the Earth’s
Surface……..
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Formation of Fossil Fuels
Formation took millions of
years…
Extraction began during
past 2,000 years
Large-scale extraction
began with steam engine
(1788), liquid petroleum
(1859)
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Why was the Steam Engine
invented?
Source: Smil 1994
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Big Dams built by Federal Govt
Hoover Dam (1935)
produces about
1,000 Megawatts of
power – about twice
as much as peak
demand in all of
Alaska
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First Commercial Nuclear Plant: 1956
Calder Hall, U.K.
4 reactors, each 23 MW
(each reactor Only 50%
more power than jet
engine…entire plant only
50% more powerful than
747 on take-off)
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The Global energy mix
• Given 50-100 years, the energy system has
consistently revolutionized itself
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Figure 1. World Energy Consumption by Source, Based on Vaclav Smil
estimates from Energy Transitions: History, Requirements and
Prospects together with BP Statistical Data for 1965 and subsequent
Avg annual growth
= (550/20)^(1/190) – 1
= 0.018 = 1.8%
http://ourfiniteworld.com/2012/03/12/world-energyconsumption-since-1820-in-charts/
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Changing Mix of World Primary
Energy “Sources” through 2000
Oil & Gas Journal 26 Jan 2004 p 19
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Changing Mix of World Primary Energy
“Sources” through 2010 and projected 2030
2000-2010 and 2011-2030 (est.) BP Stat Review “Outlook
to 2030”. Renewables does not include hydro – it is wind,
solar, geothermal, tidal/wave
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Changing Prime Movers
IC engine
steam turbine
Source: Smil 1994
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United States Energy Mix
EIA Total Energy – 10Apr 2014
http://www.eia.gov/totalenergy/
Referencing Annual Energy Outlook
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Shares of total primary energy consumed
Power plants
shift from coal
to natural gas
Renewables
rising
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4. Energy Intensity
Energy Intensity
• Total energy / Total GDP
– Data from EIA
http://www.eia.gov/totalenergy/data/annual/pers
pectives.cfm
– Example:
Energy (10^15 Btu)
GDP (10^12 $2005)
Intensity (Btu/$2005)
1949
32
1,843
17.4
2011
97
13,315
7.3
Explore at:
http://yearbook.enerdata.net/#energy-intensity-GDP-by-region.html
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20
18
Thousand Btu per Real (2005) Dollar¹
16
14
12
10
8
6
4
2
0
1949 1952 1955 1958 1961 1964 1967 1970 1973 1976 1979 1982 1985 1988 1991 1994 1997 2000 2003 2006 2009
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U.S. Energy Intensity update:
March 2013
Different units (!)
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Energy intensity falling worldwide…
U.S. economy is de-coupling itself from energy
(declining energy intensity) and de-carbonizing a bit
(switch to natural gas and renewables)
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US energy consumption
per capita has been flat for
40 years – but that’s
different than flat TOTAL
consumption…
source Metcalf 2007
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5. So What:
Energy use and Human Well-being
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Energy Use vs. Human Development
The Human
Development Index
combines life
expectancy,
education, and
income into an index
that ranges from zero
to 1
Data as of 2001, source: Smil 2003
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Energy Use vs Infant Mortality
Data as of 2001, source: Smil 2003
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Future
Future:
World energy use currently growing by
Primary energy2.5%/yr
world consumption
BP Statistical Review of World Energy
2012
© BP 2012
6. The Future
Future
• Useful decomposition:
• Impact = Population x Affluence x Technology
– “IPAT” : I = P x A x T
– “Balance of forces” approach to sustainability
• Total Energy = P x [$GDP/person]x [Energy/$GDP]
• [Energy/$GDP] = energy intensity
– Has been falling
• But GDP$/person is rocketing up in Asia
60
North America: The balance of forces is
pushing TOTAL Energy flat and Total CO2
emissions down (!)
Good news from US & N America
Total energy use flat or declining (!)
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World: Balance of forces, driven by
GDP per capita, leads to increasing
projected energy use
BP Energy Outlook 2030
63
Good news for world?
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Energy growth coming from poor countries
OECD = “Organization for Economic Cooperation and
Development” – basically the rich countries
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Renewables are increasing worldwide, but from small base
Renewable energy consumption/share of power by region
Other renewables consumption by region
Other renewables share of power generation by region
Million tonnes oil equivalent
Percentage
BP Statistical Review of World Energy
2013
© BP 2013
Global CO2 Emissions: two different stories
Data through
2010, 2010-2030
is a projection by
BP
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Take-homes for energy economics
• Humans only convert energy from one form to
another
– People want specific energy services at particular
times
– Timing is important, especially for electricity, so
storage is a big deal
• Energy services = energy + capital
– Energy is “intermediate good” with “derived demand”
– Capital is durable so energy systems change slowly
• Useful energy is lost with each conversion
• Power (watts) is the rate at which energy is
converted
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References (partial)
• Hansen, James. Defusing the Global Time Bomb. Scientific American,
February 2004. Pp. 68-77.
• Lovins A.B. Scientific American, Sep 2005
• Smil, Vaclav. 1994 Energy in World History. Westview.
• Smil, Vaclav. 2003. Energy at the Crossroads. MIT Press.
• Scott Brennan and Jay Withgott. 2003. Environment: The Science Behind
the Stories. Pearson/Cummings.
• BP Statistical Review of World Energy. Various years. online.
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