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EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsPresentation given in the course of the
Master’s ProgrammeEnvironmental Management
– Module 2.1.1 “Ecosystem Analysis” –
Aiko Huckauf
Ecology Centre Kiel
2006-07-05
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Review
Last time: Thermodynamics 101I Some remarks about the history of
thermodynamicsI Classical vs. statistical thermodynamicsI The fundamental laws of thermodynamics, e. g.
I First Law: Conservation of Energy (dU = 0)I Second Law: Increase of Entropy (∆S > 0)
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Review
Last time: Thermodynamics 101I Some remarks about the history of
thermodynamicsI Classical vs. statistical thermodynamicsI The fundamental laws of thermodynamics, e. g.
I First Law: Conservation of Energy (dU = 0)I Second Law: Increase of Entropy (∆S > 0)
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Review
Last time: Thermodynamics 101I Some remarks about the history of
thermodynamicsI Classical vs. statistical thermodynamicsI The fundamental laws of thermodynamics, e. g.
I First Law: Conservation of Energy (dU = 0)I Second Law: Increase of Entropy (∆S > 0)
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Review
Last time: Thermodynamics 101I Some remarks about the history of
thermodynamicsI Classical vs. statistical thermodynamicsI The fundamental laws of thermodynamics, e. g.
I First Law: Conservation of Energy (dU = 0)I Second Law: Increase of Entropy (∆S > 0)
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Review
Last time: Thermodynamics 101I Some remarks about the history of
thermodynamicsI Classical vs. statistical thermodynamicsI The fundamental laws of thermodynamics, e. g.
I First Law: Conservation of Energy (dU = 0)I Second Law: Increase of Entropy (∆S > 0)
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsIntroduction
I Do ecosystems obey the laws of thermodynamics?Yes, of course - as far as they are applicable.
I Is thermodynamics a useful tool to explainecosystem functioning?Well...
I Do additional concepts make thingsclearer/easier?Decide yourself.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsIntroduction
I Do ecosystems obey the laws of thermodynamics?Yes, of course - as far as they are applicable.
I Is thermodynamics a useful tool to explainecosystem functioning?Well...
I Do additional concepts make thingsclearer/easier?Decide yourself.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsIntroduction
I Do ecosystems obey the laws of thermodynamics?Yes, of course - as far as they are applicable.
I Is thermodynamics a useful tool to explainecosystem functioning?Well...
I Do additional concepts make thingsclearer/easier?Decide yourself.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsIntroduction
I Do ecosystems obey the laws of thermodynamics?Yes, of course - as far as they are applicable.
I Is thermodynamics a useful tool to explainecosystem functioning?Well...
I Do additional concepts make thingsclearer/easier?Decide yourself.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsIntroduction
I Do ecosystems obey the laws of thermodynamics?Yes, of course - as far as they are applicable.
I Is thermodynamics a useful tool to explainecosystem functioning?Well...
I Do additional concepts make thingsclearer/easier?Decide yourself.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsIntroduction
I Do ecosystems obey the laws of thermodynamics?Yes, of course - as far as they are applicable.
I Is thermodynamics a useful tool to explainecosystem functioning?Well...
I Do additional concepts make thingsclearer/easier?Decide yourself.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsIntroduction
I Do ecosystems obey the laws of thermodynamics?Yes, of course - as far as they are applicable.
I Is thermodynamics a useful tool to explainecosystem functioning?Well...
I Do additional concepts make thingsclearer/easier?Decide yourself.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsConservation of Matter
According to the mass conservation principle, mattercan be used, but not used up:
I Matter can be converted from one form intoanother, but not consumed.
I Ecosystems are characterised by constant flowsand transformations of matter:
I Carbon cycleI Nitrogen cycleI Phosphorus cycleI Water cycle
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsConservation of Matter
According to the mass conservation principle, mattercan be used, but not used up:
I Matter can be converted from one form intoanother, but not consumed.
I Ecosystems are characterised by constant flowsand transformations of matter:
I Carbon cycleI Nitrogen cycleI Phosphorus cycleI Water cycle
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsConservation of Matter
According to the mass conservation principle, mattercan be used, but not used up:
I Matter can be converted from one form intoanother, but not consumed.
I Ecosystems are characterised by constant flowsand transformations of matter:
I Carbon cycleI Nitrogen cycleI Phosphorus cycleI Water cycle
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsConservation of Matter
According to the mass conservation principle, mattercan be used, but not used up:
I Matter can be converted from one form intoanother, but not consumed.
I Ecosystems are characterised by constant flowsand transformations of matter:
I Carbon cycleI Nitrogen cycleI Phosphorus cycleI Water cycle
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsConservation of Energy
According to the First Law of Thermodynamics,dU = 0, energy can be used, but not used up:
I Energy can neither be created nor destroyed.I Energy can be converted from one form into
another, but not consumed.I Ecosystems are characterised by constant flows
and transformations of energy.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsConservation of Energy
According to the First Law of Thermodynamics,dU = 0, energy can be used, but not used up:
I Energy can neither be created nor destroyed.I Energy can be converted from one form into
another, but not consumed.I Ecosystems are characterised by constant flows
and transformations of energy.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsConservation of Energy
According to the First Law of Thermodynamics,dU = 0, energy can be used, but not used up:
I Energy can neither be created nor destroyed.I Energy can be converted from one form into
another, but not consumed.I Ecosystems are characterised by constant flows
and transformations of energy.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsConservation of Energy
According to the First Law of Thermodynamics,dU = 0, energy can be used, but not used up:
I Energy can neither be created nor destroyed.I Energy can be converted from one form into
another, but not consumed.I Ecosystems are characterised by constant flows
and transformations of energy.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsTransformation of Energy
Electromagnetic energy (light) can be transformed intochemical energy (sugar) by photosynthesis.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsTransformation of Energy
Chemical energy can be transformed into heat.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsTransformation of Energy
Chemical energy can betransformed into electricalenergy.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsSummary: Ecosystem Energy
I Ecosystems are open to energy and/or mattertransfer across their boundaries.
I Earth’s ecosystems receive a permanent flow ofenergy through solar radiation.
I Without this flow of energy, ecosystems could notdevelop—not even survive.
I (Therefore,) In ecology, the energy transfer ratedE/dt is commonly used as currency.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsSummary: Ecosystem Energy
I Ecosystems are open to energy and/or mattertransfer across their boundaries.
I Earth’s ecosystems receive a permanent flow ofenergy through solar radiation.
I Without this flow of energy, ecosystems could notdevelop—not even survive.
I (Therefore,) In ecology, the energy transfer ratedE/dt is commonly used as currency.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsIncrease of Entropy
According to the Second Law of Thermodynamics,∆S > 0, all natural (i. e. spontaneous) processesenhance the entropy of the universe.
Hence the universe will eventually degeneratetowards thermodynamic equilibrium where
I all gradients are eliminated,I all matter is transferred into its most stable
chemical state,I the entropy has reached its maximum, andI the system is dead.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsIncrease of Entropy
According to the Second Law of Thermodynamics,∆S > 0, all natural (i. e. spontaneous) processesenhance the entropy of the universe.
Hence the universe will eventually degeneratetowards thermodynamic equilibrium where
I all gradients are eliminated,I all matter is transferred into its most stable
chemical state,I the entropy has reached its maximum, andI the system is dead.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsIncrease of Entropy
According to the Second Law of Thermodynamics,∆S > 0, all natural (i. e. spontaneous) processesenhance the entropy of the universe.
Hence the universe will eventually degeneratetowards thermodynamic equilibrium where
I all gradients are eliminated,I all matter is transferred into its most stable
chemical state,I the entropy has reached its maximum, andI the system is dead.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsThe Heat Death of the Universe
Some people find this heat death of the universethought so disturbing that they want to forbid theSecond Law:
“I wouldn’t want my childgrowing up in a worldheaded for total heat deathand dissolution into avacuum. No decent parentwould want that.”Kansas state senator Will Blanchard
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsThe Heat Death of the Universe
Some people find this heat death of the universethought so disturbing that they want to forbid theSecond Law:
“I wouldn’t want my childgrowing up in a worldheaded for total heat deathand dissolution into avacuum. No decent parentwould want that.”Kansas state senator Will Blanchard
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsIntroducing Exergy
Others have replaced the problematical concept ofentropy by the more conceivable concept of exergy:
Exergy is the amount of work a system canperform when brought into thermodynamicequilibrium with its environment.
I Exergy indicates a system’s distance fromthermodynamic equilibrium: The higher the exergy,the farther the distance.
I Exergy is the available (or: usable) energy of a systemand hence a measure of energy quality: The higher thequality of the energy, the smaller the energy loss (e. g.as waste heat) when it is used.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsIntroducing Exergy
Others have replaced the problematical concept ofentropy by the more conceivable concept of exergy:
Exergy is the amount of work a system canperform when brought into thermodynamicequilibrium with its environment.
I Exergy indicates a system’s distance fromthermodynamic equilibrium: The higher the exergy,the farther the distance.
I Exergy is the available (or: usable) energy of a systemand hence a measure of energy quality: The higher thequality of the energy, the smaller the energy loss (e. g.as waste heat) when it is used.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsIntroducing Exergy
Others have replaced the problematical concept ofentropy by the more conceivable concept of exergy:
Exergy is the amount of work a system canperform when brought into thermodynamicequilibrium with its environment.
I Exergy indicates a system’s distance fromthermodynamic equilibrium: The higher the exergy,the farther the distance.
I Exergy is the available (or: usable) energy of a systemand hence a measure of energy quality: The higher thequality of the energy, the smaller the energy loss (e. g.as waste heat) when it is used.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsIntroducing Exergy
Others have replaced the problematical concept ofentropy by the more conceivable concept of exergy:
Exergy is the amount of work a system canperform when brought into thermodynamicequilibrium with its environment.
I Exergy indicates a system’s distance fromthermodynamic equilibrium: The higher the exergy,the farther the distance.
I Exergy is the available (or: usable) energy of a systemand hence a measure of energy quality: The higher thequality of the energy, the smaller the energy loss (e. g.as waste heat) when it is used.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsConsumption of Exergy
In contrast to energy, exergy can be consumed—and itis consumed during each natural (i. e. irreversible)process: After usage, energy contains a lower amountof exergy than before.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsConsumption of Exergy
I Ecosystems of different biological qualitiesconsume exergy at different efficiencies.
I The more structure an ecosystem has, the moreexergy it can capture and utilise—but the more italso needs for maintenance.
I Example: Sun radiation reflected by differentsurfaces (cf. following pages).
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsConsumption of Exergy
I Ecosystems of different biological qualitiesconsume exergy at different efficiencies.
I The more structure an ecosystem has, the moreexergy it can capture and utilise—but the more italso needs for maintenance.
I Example: Sun radiation reflected by differentsurfaces (cf. following pages).
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsConsumption of Exergy
I Ecosystems of different biological qualitiesconsume exergy at different efficiencies.
I The more structure an ecosystem has, the moreexergy it can capture and utilise—but the more italso needs for maintenance.
I Example: Sun radiation reflected by differentsurfaces (cf. following pages).
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsConsumption of Exergy
I Ecosystems of different biological qualitiesconsume exergy at different efficiencies.
I The more structure an ecosystem has, the moreexergy it can capture and utilise—but the more italso needs for maintenance.
I Example: Sun radiation reflected by differentsurfaces (cf. following pages).
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsExergy Consumption by a Mirror
A perfect mirror reflects the sun radiation without anyexergy losses.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsExergy Consumption by Asphalt
Quantum chemical processes in the asphalt consumeexergy (degrade energy quality) so that the reflectedradiation contains less exergy, i. e., the outgoingradiation is cooler.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsExergy Consumption by Lawn
Quantum chemical processes as well as metabolicprocesses of the grass will occur. Hence, the reflectedradiation will contain even less exergy and thus beeven cooler with the same incoming radiation.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsExergy Consumption by Steppe
Invading bushes and shrubs involve more biologicalactivity. Hence, the outgoing radiation during thesame circumstances will be cooler.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsExergy Consumption by Forest
Further succession brings animals and further plantsinto the area, which implies a large exergyconsumption. The outgoing radiation will thus berather cool compared to that of the perfect mirror.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsStorage of Exergy
The ripening of ecosystems increases their ability toconsume incoming solar exergy. This tendency hasbeen formulated as the tentative Fourth Law ofThermodynamics:
If a system receives a throughflow of exergy,it will utilise this exergy to move away fromthermodynamic equilibrium. If there is morethan one pathway of movement, that one islikely to be chosen which yields most storedexergy (and creates the longest distance fromequilibrium).
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsStorage of Exergy
The ripening of ecosystems increases their ability toconsume incoming solar exergy. This tendency hasbeen formulated as the tentative Fourth Law ofThermodynamics:
If a system receives a throughflow of exergy,it will utilise this exergy to move away fromthermodynamic equilibrium. If there is morethan one pathway of movement, that one islikely to be chosen which yields most storedexergy (and creates the longest distance fromequilibrium).
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsExergy vs. Entropy
Exergy and entropy are closely related:I The exergy in the universe is constantly
decreasing, the entropy increasing.I Exergy is not negative entropy, but another
description of the system.I The exergy concept is useful to describe
ecosystems and other systems far fromequilibrium (for which entropy is not defined).
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsExergy vs. Entropy
Exergy and entropy are closely related:I The exergy in the universe is constantly
decreasing, the entropy increasing.I Exergy is not negative entropy, but another
description of the system.I The exergy concept is useful to describe
ecosystems and other systems far fromequilibrium (for which entropy is not defined).
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsExergy vs. Entropy
Exergy and entropy are closely related:I The exergy in the universe is constantly
decreasing, the entropy increasing.I Exergy is not negative entropy, but another
description of the system.I The exergy concept is useful to describe
ecosystems and other systems far fromequilibrium (for which entropy is not defined).
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsExergy vs. Entropy
Exergy and entropy are closely related:I The exergy in the universe is constantly
decreasing, the entropy increasing.I Exergy is not negative entropy, but another
description of the system.I The exergy concept is useful to describe
ecosystems and other systems far fromequilibrium (for which entropy is not defined).
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsAn Illustration connecting Energy, Exergy, and Entropy
The toothpaste tube (energy) is used by squeezing outthe paste (exergy). When all paste (exergy) is used up,the tube (energy) is still there, but its usefulness(quality) has diminished. In the picture, the depressionin the tube (entropy) increases as the amount of pastediminishes—but the depression is not a negative pasteas one cannot use it to unbrush one’s teeth.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsDissipative Structures and Systems
I When the exergy flow into a system exceeds its exergyconsumption, the surplus exergy can be utilised toconstruct further order, so-called dissipative structure.
I Such emergent structures move the system furtheraway from thermodynamic equilibrium.
I Systems that show such coherent self-organisationbehaviour are called dissipative systems.
I They have to export entropy to other hierarchicallevels in order to maintain their organised state.
One obvious example for such a spontaneous creationof organisation as a result of energy flow throughecosystems is the emergence of life on Earth.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsDissipative Structures and Systems
I When the exergy flow into a system exceeds its exergyconsumption, the surplus exergy can be utilised toconstruct further order, so-called dissipative structure.
I Such emergent structures move the system furtheraway from thermodynamic equilibrium.
I Systems that show such coherent self-organisationbehaviour are called dissipative systems.
I They have to export entropy to other hierarchicallevels in order to maintain their organised state.
One obvious example for such a spontaneous creationof organisation as a result of energy flow throughecosystems is the emergence of life on Earth.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsDissipative Structures and Systems
I When the exergy flow into a system exceeds its exergyconsumption, the surplus exergy can be utilised toconstruct further order, so-called dissipative structure.
I Such emergent structures move the system furtheraway from thermodynamic equilibrium.
I Systems that show such coherent self-organisationbehaviour are called dissipative systems.
I They have to export entropy to other hierarchicallevels in order to maintain their organised state.
One obvious example for such a spontaneous creationof organisation as a result of energy flow throughecosystems is the emergence of life on Earth.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsDissipative Structures and Systems
I When the exergy flow into a system exceeds its exergyconsumption, the surplus exergy can be utilised toconstruct further order, so-called dissipative structure.
I Such emergent structures move the system furtheraway from thermodynamic equilibrium.
I Systems that show such coherent self-organisationbehaviour are called dissipative systems.
I They have to export entropy to other hierarchicallevels in order to maintain their organised state.
One obvious example for such a spontaneous creationof organisation as a result of energy flow throughecosystems is the emergence of life on Earth.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsDissipative Structures and Systems
I When the exergy flow into a system exceeds its exergyconsumption, the surplus exergy can be utilised toconstruct further order, so-called dissipative structure.
I Such emergent structures move the system furtheraway from thermodynamic equilibrium.
I Systems that show such coherent self-organisationbehaviour are called dissipative systems.
I They have to export entropy to other hierarchicallevels in order to maintain their organised state.
One obvious example for such a spontaneous creationof organisation as a result of energy flow throughecosystems is the emergence of life on Earth.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsDissipative Structures and Systems
I When the exergy flow into a system exceeds its exergyconsumption, the surplus exergy can be utilised toconstruct further order, so-called dissipative structure.
I Such emergent structures move the system furtheraway from thermodynamic equilibrium.
I Systems that show such coherent self-organisationbehaviour are called dissipative systems.
I They have to export entropy to other hierarchicallevels in order to maintain their organised state.
One obvious example for such a spontaneous creationof organisation as a result of energy flow throughecosystems is the emergence of life on Earth.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsIntroducing Emergy
Emergy is the amount of energy that is requiredto make something: The more energy has to betransformed to produce something, the higherthe emergy content of the product.
I Emergy (expressed in emjoules, ej) can be used asbasis of a donor system of value, while energy/heatevaluation (expressed in joules, J) or economicvaluation (expressed in monetary units) are receiversystems of value.
I For the Emergy Accounting valuation method, allforms of energy and materials are first converted intoequivalents of one form of energy so that the value ofboth energy and material resources required toproduce something can be measured within acommon framework.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsIntroducing Emergy
Emergy is the amount of energy that is requiredto make something: The more energy has to betransformed to produce something, the higherthe emergy content of the product.
I Emergy (expressed in emjoules, ej) can be used asbasis of a donor system of value, while energy/heatevaluation (expressed in joules, J) or economicvaluation (expressed in monetary units) are receiversystems of value.
I For the Emergy Accounting valuation method, allforms of energy and materials are first converted intoequivalents of one form of energy so that the value ofboth energy and material resources required toproduce something can be measured within acommon framework.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsIntroducing Emergy
Emergy is the amount of energy that is requiredto make something: The more energy has to betransformed to produce something, the higherthe emergy content of the product.
I Emergy (expressed in emjoules, ej) can be used asbasis of a donor system of value, while energy/heatevaluation (expressed in joules, J) or economicvaluation (expressed in monetary units) are receiversystems of value.
I For the Emergy Accounting valuation method, allforms of energy and materials are first converted intoequivalents of one form of energy so that the value ofboth energy and material resources required toproduce something can be measured within acommon framework.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsSolar Emergy
I The usual reference for emergy calculations is solarenergy.
I The solar emergy of a product (expressed in solaremjoules, sej) is the emergy of the product expressedin equivalent solar energy required to generate it.
I To derive solar emergy of a product, resource, orcommodity, all resources that have been used toproduce it have to be traced back and expressed in theamount of solar energy that went into their production.
I Based on such calculations, a transformationcoefficient (transformity = emergy/energy, expressed insej/J) can be derived and used for future calculationsto convert energy into emergy.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsSolar Emergy
I The usual reference for emergy calculations is solarenergy.
I The solar emergy of a product (expressed in solaremjoules, sej) is the emergy of the product expressedin equivalent solar energy required to generate it.
I To derive solar emergy of a product, resource, orcommodity, all resources that have been used toproduce it have to be traced back and expressed in theamount of solar energy that went into their production.
I Based on such calculations, a transformationcoefficient (transformity = emergy/energy, expressed insej/J) can be derived and used for future calculationsto convert energy into emergy.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsSolar Emergy
I The usual reference for emergy calculations is solarenergy.
I The solar emergy of a product (expressed in solaremjoules, sej) is the emergy of the product expressedin equivalent solar energy required to generate it.
I To derive solar emergy of a product, resource, orcommodity, all resources that have been used toproduce it have to be traced back and expressed in theamount of solar energy that went into their production.
I Based on such calculations, a transformationcoefficient (transformity = emergy/energy, expressed insej/J) can be derived and used for future calculationsto convert energy into emergy.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsSolar Emergy
I The usual reference for emergy calculations is solarenergy.
I The solar emergy of a product (expressed in solaremjoules, sej) is the emergy of the product expressedin equivalent solar energy required to generate it.
I To derive solar emergy of a product, resource, orcommodity, all resources that have been used toproduce it have to be traced back and expressed in theamount of solar energy that went into their production.
I Based on such calculations, a transformationcoefficient (transformity = emergy/energy, expressed insej/J) can be derived and used for future calculationsto convert energy into emergy.
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
ReferencesFor Further Reading. . .
I Sven Erik Jørgensen and Felix Müller (Ed.): Handbook of EcosystemTheories and Management. CRC Press, Boca Raton, 2000.
I Sven Erik Jørgensen: Integration of Ecosystem Theories: A Pattern.Kluwer Academic Publishers, Dordrecht, 1992.
I James J. Kay’s homepage http://www.jameskay.ca/ provides plentifulinformation about Thermodynamics and Ecology in general(http://www.jameskay.ca/about/thermo.html) as well as Exergy inparticular (http://www.jameskay.ca/about/exergy.html).
I Folke Günthe: The Laws of Thermodynamics. Available online athttp://www.holon.se/folke/kurs/Distans/Ekofys/fysbas/LOT/LOT.shtml.
I David Watson: Energy Concepts for Educators and Students.Available online at http://www.ftexploring.com/energy/energy.html.
I M. T. Brown and S. Ulgiati: Emergy evaluation of natural capital andbiosphere services. AMBIO 28(6), 486–493 (1999).
EcosystemThermodynamics
Aiko Huckauf
Review
EcosystemThermodynamicsIntroduction
Matter
Energy
Entropy
Exergy
Illustration
Dissipative Structures
Emergy
References
Ecosystem ThermodynamicsThe obligatory last slide. . .
Thank you for your attention!
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