Net Energy And The Economy


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By G.Mobus, PhD
A Tutorial on Net Energy and Its Relation to the Economy

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Net Energy And The Economy

  1. 1. Net Energy and the Economy George Mobus, Ph.D., Associate Professor, Institute of Technology, University of Washington Tacoma
  2. 2. Overview What is Net Energy? What is the problem? How is it Related to the Economy? ◦ Economic Work ◦ Macroeconomic View ◦ Microeconomic View What is Happening with Net Energy? What Are the Consequences?
  3. 3. Why Focus on Net Energy? Current focus on gross or raw energy resources and peak oil Net energy is ALWAYS less than gross inputs Net energy is what the economy runs on Net energy has already peaked! What does this mean for the economy?
  4. 4. Energy and Work All economic work is accomplished with high power energy inputs Types of energy are coupled with the prime movers, heaters, appliances ◦ Oil → diesel → ICE → moving people & stuff ◦ Coal → boiling water → driving turbines → generating electricity → lighting the house ◦ Natural gas → mixed uses, transportation, heating, electricity The final use determines the economic benefit – covered later
  5. 5. Energy CostsExample: Refining oil into diesel requires using some of that fuel (or its energyequivalent) to keep the process going. every transformation results in the loss of non-recoverable heat pumping & transport high quality energy stock Oil refining Diesel flow what is left over for stock process/ society transformation reinvestment of high quality energy to produce refined energy
  6. 6. What Is Net Energy? Raw or Gross Energy ◦ barrels of oil Energy Capture and Conversion ◦ oil exploration, drilling, pumping, transporting, and refining Energy used to capture and convert to usable form ◦ building capital equipment (investment) ◦ operations: labor, pumping, transporting Energy Return on Energy Invested
  7. 7. Usable Energy Stream gross energy energy invested energy delivered Underground: theoretical reserves Extracted: actual recoverable reserves Usage: Distribution and storage: Usable products:
  8. 8. Net Energy Usable energy form after capture and conversion, e.g. gasoline with high energy content per unit volume (weight) Net energy is used to either: ◦ get more energy ◦ used by the productive/consumption economy Net energy to the economy, NEE NEE = GE t- NEI t +1 t -1
  9. 9. Principles Absolutely nothing happens (no work gets done) without a flow- through of high potential energy. All energy eventually degrades to waste heat (2nd Law of Thermodynamics). To produce high quality usable energy requires energy be reinvested. Net energy to society is less than the raw energy input. Raw Energy oil wells/refineries solar panels wind mills Waste heat Net Energy to Energy Economy, NEE Real-time solar (agriculture) Production Fossil solar (coal, oil, gas) Nuclear Short-time solar (wood, water) Net Energy Invested, NEI Consuming Economy Natural Resources Recycled Waste materials materials
  10. 10. Additional ImportantConsiderations As the raw energy from fixed finite resources, like fossil fuels, are depleted the amount of high-grade energy needed to reinvest to obtain new energy increases. Energy return on energy (re) invested (EROI) diminishes over time. Without new sources of renewable energy (real-time solar, wind, etc.) that scale up to replace the lost fossil fuels, the net energy to society continues to decline. Peak oil is a test case. Raw Energy with smaller contribution from fossil fuels. Energy Less net energy Production for society Energy reinvestment
  11. 11. Economic Work The physics definition of work ◦ mechanical (motors moving things) ◦ electrical (convertible to mechanical) ◦ chemical ◦ biophysical/chemical Economic work (definition) ◦ changing material forms for use ◦ moving material goods ◦ providing services ◦ any activity that supports human life
  12. 12. Economic Work – A SimpleExample: Getting Food Catching by hand Investing some of your energy (effort) in constructing a spear Increasing the efficiency of obtaining the next unit of food More food to supply offspring Teach offspring to make spears Ultimate products: More human biomass
  13. 13. Basic Model:Primitive Economics waste heat energy store an Individual energy and material food source material material sink food getting all other living process processes reinvestment efficiency increase economic hunting equipment, food technology work preparation; also clothing, shelter discretionary artifacts esthetics decorations, trinkets, leisure enhancement decay
  14. 14. Energy Efficiency – Technology andProductivity  The historical benefit of technology has generally been to increase the efficiency of work processes.  Increasing technology increases complexity  Local vs. Global efficiencies  Jevons’ Paradox  Productivity should not be confused with efficiency  Effects of rapid expansion of raw energy availability  Effects of initial technology improvements and Law of Diminishing Returns
  15. 15. Biophysical Macroeconomic View money/information flow raw material flow total low-entropy raw material flow raw energy waste heat high-entropy energy material flow source energy flow energy exergy extraction process raw waste material production consumption material material extraction process process sink A process waste source product (emergy) money intermediate information material products recycling extraction (parts -emergy) process raw wages labor and material families B source labor energy
  16. 16. Relationship Between Energy andMoneyHoward Odum, and others energy to move product energy to consume product purchase energy to message energy to drive drive extraction product production no one pays producer consumer nature extractor X waste material purchase matter X waste message no one pays nature matter Households Firms wages message An impossibility theorem: The money spent to purchase must << than the money used to pay wages!
  17. 17. Net Energy Investment usable net energy to raw energy the economy capture & conversion consumer capital equipment economy usable net energy maintenance & repair life investment support raw material material capital equipment production plant & labor extraction & processing equipment Building capture & conversion capital equipment life cycle waste capital production Building buildings and equipmentCapturing & converting raw energy into usable energy requires a whole substructure ofproduction that takes considerable energy to grow, maintain, and operate. If raw energy source is shrinking, then it is necessary to boost energy/material inputs to compensate. Which means less net energy to support the consumer economy.
  18. 18. An Economy Dependent on Fossil Fuels 40 35 The Biophysical Economy Post Peak-Fossil Fuels 30Energy (flow and embodied) 25 20 15 10 5 0 TIME 100 103 106 109 112 115 43 82 10 13 16 19 22 25 28 31 34 37 40 46 49 52 55 58 61 64 67 70 73 76 79 85 88 91 94 97 4 1 7 Total Gross Net FF Net Alt. Total Net Total Assets Total assets = All artifacts and all biomass
  19. 19. Net Energy Peak and Decline We are already in net energy decline from fossil fuels Diminishing EROI in fossil fuel extraction, conversion, and distribution Renewable (alternative) sources cannot scale up anytime soon Renewables may not have a sufficiently high EROI to be sustainable
  20. 20. The Future of Economic Work Declining net energy means less work can be accomplished Channel remaining energy resources away from esthetic and hedonic products and toward appropriate technology Technology that increases global net energy should be favored
  21. 21. Conclusion The economy must necessarily contract as the total net energy available to do useful work declines Since >80% of our energy comes from fossil fuels, and since oil extraction rates appear to have topped out, our net available energy is already in decline We had better find ways to better manage what energy flows we have left
  22. 22. Thank you Q &A