EMERGY & ENERGY SYSTEMSEMERGY & ENERGY SYSTEMS

Session 1 Short Course for ECO Interns,

EPA and Partners

Topics IntroducedTopics 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

GOALSGOALS

• 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

Energy and EcologyEnergy and Ecology

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

Goals for this unit

HierarchyHierarchyFood Chains and Pyramid ChartsFood Chains and Pyramid Charts

HierarchyHierarchyFood Chains and Pyramid ChartsFood Chains and Pyramid Charts

CarnivoresGrazersPlantsSun

More quantitative perspective

HierarchyHierarchyFood Chains and Pyramid ChartsFood Chains and Pyramid Charts

Think left to right

HierarchyHierarchy

Heat SinkEntropyDissipated Energy

Less available energyConcentrated and able to do more work

Water,CO2

Fertilizer

ConcentrationConcentrationO2,

H2OO2,

H2O

ConcentrationConcentration

1000

10010

1

100 10

1110 (1109)

Producer

Consumer

Force

Force Force

Consumer

PatternsPatterns

Patterns - Patterns - point sourcepoint source

• Wells• Springs

Patterns - Patterns - line sourceline source

• Coast• Highway• River

Patterns - PlanarPatterns - Planar

• Sun• Rain

Patterns – combined sourcesPatterns – combined sources

• Point and line

Thermodynamic LawsThermodynamic Laws

First law of thermodynamicsLaw 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 = Q - W

Thermodynamic LawsThermodynamic 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 = K*log(N)

dS = dSsystem + dSsurroundings

Forms of EnergyForms of Energy

• light

• chemical

• mechanical

• heat

• electric

• atomic

• sound

Theoretical EnergyTheoretical Energy

• Potential

stored energy of position

• Gravitational

PEgrav = m*g*h

• Elastic

PEspring = ½*k*x2

Theoretical EnergyTheoretical Energy

• KineticKE = ½*m*v2

energy of motion

• vibrational

• rotational

• translational

Theoretical EnergyTheoretical Energy

• Gibbs Free

dG = dH –d(TS) G – G0 = RT ln fi

f0

fi,0 = f(molarity of solutions)

Energy TermsEnergy Terms

• HeatTemperature

• WorkW = F(orce) x D(istance) x cos

• How far does it move• How hard to get it there

Energy TermsEnergy Terms

• Power

Rate at which work is done

Power = worktime

Energy TermsEnergy Terms

• Units of measure

Joule (J) – kg*m2/s2

Newton (N) – kg*m/s2

Kilowatt (kW) – 1000J/s

Energy and Ecology TermsEnergy and Ecology Terms

• Limiting factors

• Interactions

• Stress reactions

Maximum Power PrincipleMaximum Power Principle

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

Lotka, 1922

Autocatalytic feedback

Maximum Power PrincipleMaximum Power Principle

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

No feedback or storage

Energy ConversionEnergy Conversion

• Dimensional analysis

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

bbl gal BTU

• Dimensional analysis

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

bbl gal BTUxx

• Dimensional analysis

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

bbl gal BTUxx

xx

• Dimensional analysis

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

bbl gal BTUxx

xx

xx

Energy ConversionEnergy 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

Check Your Conversions Check Your Conversions Check mine, tooCheck 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 (0.24*24 KJ + 0.04*39 KJ + 0.72*17KJ) 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