EMERGY

1
EMERGY ENERGY SYSTEMS
Session 1 Short Course for ECO Interns, EPA and
Partners
2
Topics Introduced

• Energy/ecology/systems
• Energy language systems diagrams
• Fundamental emergy concepts
• Emergy evaluations
• Emergy and economics
• Evaluating tangibles
• Evaluating information

• Ratios and interpretations
• Scale and boundary definition
• Spatial emergy concepts
• Emergy as decision tool
• Comprehensive state and regional evaluations
• State and regional case studies

3
GOALS

• Diagram a complex system network using energy
  systems language symbols
• Aggregate diagram to answer a question
• Identify data required for evaluation
• Understand conversion of raw data into kinetic or
  potential energy amounts
• Understand theory of emergy ratios and how to
  choose the right one

4
Energy and Ecology
Goals for this unit

• Hierarchy and concentration
• Natural patterns
• Thermodynamic Laws
• Measurement heat, work
• Flows and forces
• Available, free, dispersed energy
• Limiting factors and interactions
• Maximum power principle

5
HierarchyFood Chains and Pyramid Charts
6
HierarchyFood Chains and Pyramid Charts
Carnivores Grazers Plants Sun
More quantitative perspective
7
HierarchyFood Chains and Pyramid Charts
Think left to right
8
Hierarchy
Less available energy Concentrated and able to do
more work
Heat Sink Entropy Dissipated Energy
9
Concentration
Water,CO2 Fertilizer
O2, H2O
O2, H2O
10
Concentration
Force
Force
100
10
1
Consumer
1000
10
Force
100
Producer
Consumer
1110 (1109)
11
Patterns
12
Patterns - point source

• Wells
• Springs

13
Patterns - line source

• Coast
• Highway
• River

14
Patterns - Planar

• Sun
• Rain

15
Patterns combined sources

• Point and line

16
Thermodynamic Laws

• First law of thermodynamics
• Law of Conservation
• The total energy of any system and its
  surroundings is conserved.
• i.e.Energy is neither created nor destroyed, it
  changes from one form to another.
• dU dQ - dW

17
Thermodynamic Laws

• The Second Law of Thermodynamics
• The entropy change of any system and its
  surroundings, considered together, resulting from
  any real process, is positive and approaches a
  limiting value of zero for any process that
  approaches irreversibility.
• dS dQrev/T S Klog(N)
• dS dSsystem dSsurroundings

18
Forms of Energy

• light
• chemical
• mechanical
• heat
• electric
• atomic
• sound

19
Theoretical Energy

• Potential

• stored energy of position
• Gravitational
• PEgrav mgh
• Elastic
• PEspring ½kx2

20
Theoretical Energy

• Kinetic

• KE ½mv2
• energy of motion
• vibrational
• rotational
• translational

21
Theoretical Energy

• Gibbs Free

dG dH d(TS) G G0 RT ln fi
f0 fi,0 f(molarity of
solutions)
22
Energy Terms

• Heat
• Temperature
• Work
• W F(orce) x D(istance) x cos N
• How far does it move
• How hard to get it there

23
Energy Terms

• Power

Rate at which work is done Power work
time
24
Energy Terms

• Units of measure

Joule (J) kgm2/s2 Newton (N)
kgm/s2 Kilowatt (kW) 1000J/s
25
Energy and Ecology Terms

• Limiting factors
• Interactions
• Stress reactions

26
Maximum Power Principle

• Systems prevail that develop designs that
  maximize the flow of useful energy.
• Lotka, 1922

Autocatalytic feedback
27
Maximum Power Principle

• When energy inputs are low, no feedback or
  storage develops and energy is dispersed.

No feedback or storage
28
Energy Conversion

• Dimensional analysis

• 1bbl oil x 42 gal x 1.26E5 BTU x 1055 J 5.6E9 J
• bbl gal
  BTU

29

• Dimensional analysis

x

• 1bbl oil x 42 gal x 1.26E5 BTU x 1055 J 5.6E9 J
• bbl gal
  BTU

x
30

• Dimensional analysis

x
x

• 1bbl oil x 42 gal x 1.26E5 BTU x 1055 J 5.6E9 J
• bbl gal
  BTU

x
x
31

• Dimensional analysis

x
x
x

• 1bbl oil x 42 gal x 1.26E5 BTU x 1055 J 5.6E9 J
• bbl gal
  BTU

x
x
x
32
Energy Conversion

• Practice conversions using dimensional analysis

• 1.2E6 gal water to grams
• Average of 56 KW electricity every hour for one
  week to J
• 1.3 short ton bituminous coal to J
• 112 bushels cucumbers to J
• 100 lb 10-9-11-5 fertilizer to grams P, grams N
  and grams K

33
Check Your Conversions Check mine, too

• 1.20E6 gal H2O x 3785.4 cm3 x 1.00 gram H2O
  4.54E9 grams H2O
• U.S. gal cm3
  H2O
• 56.0 KW x 1 week x 168.0 hours x 3.6E6 J
  3.4E10 J
• hr week
  KWH
• 1.3 tons x 2000 lb x 13,500 BTU x 1055 J
  3.7E10 J
• short ton lb bituminous BTU
• 112 bushels X 55 lb x 454 g x (1-0.964) x
  (0.2424 KJ 0.0439 KJ 0.7217KJ) x 1000J
  1.97E9 J
• bushel lb
  g g
  g KJ
• 100 lb fertilizer x 454 grams x 0.09g P2O5 x
  62 gmoles P 1784
  gP
• lb
  g fert. 142 gmoles P2O5
• 100 lb fertilizer x 454 grams x 0.1g N x
  
  4540 gN
• lb
  g fert.
• 100 lb fertilizer x 454 grams x 0.11g K2O x
  78.2 gmoles K 2750
  gK
• lb
  g fert. 142 gmoles K2O