Daniel E. Campbell, PhD. Systems Ecologist Institute of Geography, Henan Academy, Zhengzhou, China July 1, 2010 An Introduction to Energy Systems Theory, Emergy Analysis, Environmental Accounting, and Ecosystem Modeling
Outline of the Presentation • I. Introduction • II. Energy Systems Theory • II A. The Energy Systems Language • II B. Common Patterns in Nature • III. Emergy and Transformity • IV. Emergy Analysis • V. Energy Systems Modeling • VI. Environmental Accounting • VII. The Future of Emergy Research
I. The Odum Brothers 两 个男人 创 这个 概念 弟弟 哥哥 H.T. Odum teaching students about forest ecosystems
他们 闻名 的 父亲 - Howard Washington Odum - 给了他们 最好 的生 命 帮助 社会 . A Famous Father • Father, Howard Washington Odum (1884-1954), was a famous sociologist, who thought in terms of systems. • He realized that a physical basis was needed to understand society and social organization. • Sons, Eugene P. (1913-2002) and Howard T. (1924-2002) were pointed toward this task for their lifework by their father.
The Fathers of Systems Ecology • In 1953, Eugene wrote the first book on the principles of ecology from a top-down systems perspective in collaboration with H.T. • H.T. wrote the chapter on energy that was included in that book.
The Brothers Life Work • H.T. was the younger brother but he was the more original thinker. He has been called the great innovator. • Eugene was a great synthesizer. He was able to express his brother’s complex ideas and his own in simple terms. He has been called the great communicator. • They were awarded many prizes and honors together including the Prix de L'Institut de la Vie and the Crafoord Prize. • I am a student of H.T. Odum and I studied with him for 26 years.
Quote from “Energy Basis for Man and Nature” • “Everything is based on energy. Energy is the source and control of all things, all value, and all the actions of human beings and nature. This simple truth long known to scientists and engineers, has generally been omitted from most education in this century.” • H.T. and E.C. Odum (1976)
H.T. Odum’s Unique Insight • An integrated and comprehensive understanding of all phenomena can be achieved through a systematic consideration of the laws and principles governing the creation and use of available energy, i.e., energy with the capacity to do work. • From this insight he and his colleagues developed a comprehensive accounting system for man and nature.
II. Energy Systems Theory (EST) • Perhaps, H.T. Odum’s greatest contribution to science was to bring together a set of unifying concepts within EST to consolidate our understanding of all kinds of systems. • Knowledge from general systems theory, irreversible thermodynamics and ecology were synthesized to create EST, which was applied to better understand all natural phenomena
What EST Seeks to Accomplish • Unification of all systems through the expansion of equilibrium thermodynamic principles to include principles that explain nonequilibrium phenomena. • This is thermodynamics (sensu lato).
The Human Condition • We are embedded in a universe that is organized in a hierarchical fashion in space and time. • Being within and a part of this complex network, we see so many details that it is easy to become bewildered. • In this situation the ability to create models is a necessary survival skill.
Gödels Theorem • No system can understand itself because more system components are required to analyze and understand than to simply function. • People create models to understand the structure and function of the complex world in which we are embedded even though we can not perceive this world all at once.
II. A Energy Systems Language (ESL) • The primary tool that Dr. Odum developed to better represent and understand complex natural phenomena from an energy perspective was the Energy Systems Language.
ESL continued • Language was developed to combine kinetics, energetics, and economics. • ESL does mathematics symbolically and at the same time keeps track of the energy laws. • The ESL diagrams are really a form of mathematics that extend the capacity of the mind to see wholes and parts simultaneously. • ESL is useful for teaching, research, and comparison of systems languages.
Energy Systems Language Symbols • The symbols of ESL are used to trace causality and show interrelationships in networks of energy pathways, storages and interactions. • Each symbol is mathematically defined thus the diagram when drawn specifies a set of simultaneous 1st order differential equations to be solved. • ESL is a meta-language, therefore all models in other languages can be translated into ESL, since the phenomena that they represent must have an energy basis.
Application of the Energy Laws in ESL • Every energy systems model must have an evaluated 1st law diagram that insures conservation of energy and matter. • Every ESL model disperses heat from work gates and storages through the heat sink satisfying the 2nd law. • ESL models are used to look for design principles that follow from the maximum power principle (4th law).
ESL Modeling:Features of an ESL Model • System boundaries • Outside energy sources or forcing functions • Internal components or state variables • Outflows across the boundaries, e.g., exports, or the heat sink. • Outside sources and inside storages interact through work gates to generate fluxes of matter and energy within the system.
Energy Source E3 J5 Energy Source E 2 J4 J37 J6 process p13 Structure Q5 Structure Q7 J32 J30 process p9 J8 J33 J7 J29 J9 J28 J31 Structure Q4 Structure Q6 J25 J27 J13 J26 J36 J10 J35 process p2 process p1 process p7 process p5 J34 J11 J12 J24 J22 Energy Source E1 process p11 J1 J17 J14 Structure Q3 Structure Q1 Structure Q2 J15 J18 J20 J23 J21 process p3 process p10 process p6 process p4 process p8 process p12 J2 J16 J19 JR Figure 7. Campbell, An Energy Systems... A Generic Energy Systems Model Showing Main Features.
II B. The Unity of All Systems • Everything is connected within one universal system. • A window of attention in space and time simplifies this complexity. • Common patterns are created by the transformation of available energy governed by the 4th law of thermodynamics.
Common Patterns • Storage of energy and material. • Energy transformations. • Feedback reinforcement. • Circulation of materials. • Hierarchical organization. • Self-organization for maximum power.
The Energy Systems Approach • The existence of common designs and similar patterns is a starting point for modeling using Energy Systems Theory. • The transformation of energy underlies action and organization at every scale. • Hierarchical design occurs on all scales. • It has distinctive properties that help us understand systems.
Hierarchy of Systems Organization Environmental Policy Window
A Common Design on all Scales • As potential energy flows from source to sink self-organization for maximum power generates stored potential energy that is more organized than its background. • This difference constitutes a low entropy source of available energy that can feedback special work. • Materials cycle between the ordered and disordered parts of the system.
Positive feedback is a widespread design principle in nature. Autocatalytic designs develop when enough potential energy is available. A positive feedback, PF, from storage to a work gate that further stimulates energy inflow maximizes power in a system. Stored Potential Energy Positive feedback Strong source of potential energy PF Work Trans- formation Heat dispersal Used energy Weak source of potential energy Diffusion Weak energy sources degrade without developing positive feedback loops. Dispersed energy
Nature’s Pulsing Paradigm • The pulsing paradigm replaces the old concept of growth followed by steady state. • Systems with coupled pairs of components can oscillate. • Such pairs are found on all hierarchical levels of organization. • Pulsing pairs contain one component, the accumulator, that slowly builds up resources and a second component, the frensor, that rapidly consumes the accumulated resources.
X Design of a Pulsing System Frenzor Material, M TM = 200 k7 Consumers C =2 2.5E-5 k6 3E-4 k3 0.0003 Energy E= 5 Resources R = 2 k4 0.02 k2 k5 X 0.2 0.01 k1 0.005 Accumulator
Pulsing on nested levels of hierarchical organization. 100000 1000 Level 3 Dispersed Material 100000 1000 Energy 100000 ST = 1 Resource Consumption Accumulated Resource 100000 100000 10000 100000 10000 100 Dispersed Material Level 2 10000 100 Energy 10000 ST = 1 Resource Consumption Accumulated Resource 10000 10000 1000 10000 1000 10 Dispersed Material Level 1 1000 10 Energy 1000 ST =1 Resource Consumption Accumulated Resource 1000 1000 100 1000
III. Emergy and Transformity • The concepts of emergy and transformity can be derived by considering the transformations of energy in a hierarchical network. • The position of an energy storage or flow within the network determines its transformity and the kind of work that it can do when used.
106 = 102 104 Solar Joules per time Solar Energy 106 104 103 102 10 Joules per time 105 Transformity = 103 104 Spatial Hierarchy Hierarchical Design is a corollary of the maximum power principle.
Definition of Emergy • Emergy is all the available energy of one kind previously used up both directly and indirectly in making a product or service. • Emergy has units of emjoules to connote energy used in the past. • A quantity of emergy is always tied to an underlying quantity of available energy flowing through or stored in the system.
Transformity • Solar Transformity is the solar emergy required to make one joule of available energy of a product or service. • It increases with each successive transformation in the network. • Transformity has units of sej/J. • The transformity of a item is its emergy divided by its available energy. • Emergy(sej) = Available Energy (J) x Transformity(sej/J)
Maximum Power Design • System designs that maximize empower prevail in competition. • Nature’s ubiquitous patterns are the result of such designs. • Pulsating systems at all scales may be one such design.
IV. Emergy Analysis • Emergy as a Basis for Systems Analysis • Emergy Evaluation is required for both analysis and synthesis • Emergy Analysis, starts with the whole and examines the functions of the whole and its parts • Emergy Synthesis starts with the parts and integrates them into a functional whole. • Both approaches are methods used in Emergy research.
Emergy Analysis Method • Construct Model Diagram • Collect Necessary Information • Evaluate Model • Calculation of Indicators • Formation of Indices • Interpretation of results within the framework of Energy Systems Theory.
Two Major Classes of Emergy Analyses • Analysis of whole systems like a state, province, nation or region. Also subsystems such as agriculture, urban systems etc. fall in this class. • Analysis of production processes, like steel making, rice growing, aquaculture, etc.
Additional Emergy Methods • Development of Indices • Comparison of Alternatives, i.e., determine the affect of incremental or marginal changes on system empower or other output that result from alternative designs or policies. • Emergy matching in development and production processes • Evaluate the effects of trade in terms of the emergy exchange • Evaluate the effects of alternative policies on multiple levels of hierarchical organization.
Goods Services Government Reserve ¥ Infrastructure MG Donors Visitors YMD+YMV MD+MV F FE MD+MV Rain FC Tide Waves Y Animal Resources MY Large Ecosystem Z YM Market YN Plant Resources B Peat MY N1=P R N01=DB Mud N02=OM Wetland Reserve Conservation Value, CV = Q+YN =P+B +OM +YN SSR =(YM+YMD+YMV)/F =(MY+MD+MV)(Em/$)/(FC+FE) ECR = CV/Fc EBR =(CV+Y)/F EBE =(CV+YM+YMD+YMV)/(CV+Y) EISD = EBR×EBE/ELR MY -- the money received for economic services and products; MD -- the money contributed by private donors for conservation; MV -- the entrance fees paid by visitors; YMD -- the emergy purchased with money contributed by private donors; YMV -- the emergy purchased with money from visitors; YMG -- the emergy purchasing power of the money contributed by government to support the reserve; FC --the emergy purchased to support conservation, which is equal to YMD+YMV +YMG; FE --the emergy purchased to support economic production.
Emergy Analysis: Normalizing the Phenomenal Universe • Emergy can be used to express all phenomena on a common basis so that values are directly comparable. • This is true if (1) the transformation of energy underlies all phenomena and • (2) if the energy previously used up directly and indirectly to make an item can be accounted for as energy of one kind (e.g., solar emjoules).
Eastport Pembroke 4m Tidal Range High Velocity Channels Lubec Emergy Evaluation of Cobscook Bay Ecosystem
Cobscook Bay: Overview • A macrotidal ecosystem that is naturally eutrophic due to new nitrogen supplied from the sea. • Plant production is stabilized by benthic macrofauna grazing. • Phytoplankton production is light limited. • Fuciods, kelp, red algae and benthic diatoms are best adapted to utilize the energy signature of the Bay. Low Tide High Tide