Bruce Mayer, PE Licensed Electrical & Mechanical Engineer BMayer@ChabotCollege

1. Engineering 10 Chp.6 EnergyEROEI - Nuclear Bruce Mayer, PE Licensed Electrical & Mechanical EngineerBMayer@ChabotCollege.edu

2. EROEI • Energy Returned On Energy Invested • Energy Invested – in order to: • ACQUIRE energy, it TAKES ENERGY. • TRANSPORT a form of energy, TAKES ENERGY. • STORE energy, TAKES ENERGY. • USE energy, also TAKES ENERGY

3. EROEI • Energy Returned On Energy Invested • Energy Returned: • After you have taken into account all the energy used in the last slide...how MUCH ENERGY do you have left? • OR How much energy does it actually COST in order to USE a particular form of energy?

4. EROEI - Analogy • Say that you have $100 that you want to INVEST at a bank. • The bank is offers an account for a year that pays 10% interest. • Check the TOTAL Gain or LOSS From this Investment • What if you didn't have a car so you take the Bus to the Bank. It costs you $4 to catch the bus round-trip to go to the bank and deposit the money. • At the end of 6 months, you pay another $4 to catch another bus to the bank to withdraw your money and interest. • The math on This investment: • $100 + 10% intererest = $110 at the end of the year. • MINUS $4 for the first bus and another $4 for the 2nd bus = $8 total. • Subtracting the $8 from the $110 that leaves a total of $102; • Thus the RETURN on your investment = 2/100 = 2% • Not such a good deal after all

5. EROEI Graphically Note: EROI ↔ EROEI • If there is NO Surplus, then Eout/Ein <1, and We have WASTED energy

6. EROEI – Fuel (Thermal) Energy

7. EROEI – Electrical Energy • From these Lists We Spot a Couple of Dicey Propositions • Solar Electricity • Corn Ethanol as a fuel

8. Energy Sources – Fact & Fancy • Question – Which Energy Source Has These Attractive Aspects • NO HydroCarbon or NOx Emissions • NO GreenHouse Gas Emissions • Very High Energy Density • Easy to Transport Fuel • Plug-Compatible With Existing Electrical Grid • Can Easily Produce Hydrogen During “Off Peak” Hours • Low Energy Inputs to Produce?

9. Answer → Nuclear (Fission) Power

10. Energy Sources – Fact & Fancy • Nuclear Fission Limitations • Waste Handling is a Political Issue • Have Technological Solutions • Waste Concentration, and Then Storage in Water-Free, Geologically Stable Salt-Mine Structures • Fear of Accidental Radiation Releases Due to Loss of Coolant Accidents Such as TMI • New Designs are Fail-Safe; LoCA’s can Be Engineered OUT • ByProduction of Nuclear-Weapons Compatible Materials; e.g., Plutonium

11. Energy Sources – Future • Any of the Previous Techniques Could Benefit from Technology “BreakThrus” • Possible Examples • A BioEngineered Fermentation Enzyme Greatly Reduces Energy Required to Make Ethanol • Nuclear FUSION • Fission: Break a Heavy Atom (Uranium) to Liberate Heat (and Neutrons) • FUSION: Combine Light Hydrogen Atoms to Liberate Heat (and Make Heavier Helium Atoms)

12. Energy Sources – Future cont • Fusion Produces MUCH LESS Radioactive Material Than Fission Reactors • But it’s NOT Zero • Fuel is “Heavy Water” Isotopes That are in More than Sufficient Supply in Sea Water • Fusion Limitations • An EXTREMELY Difficult Technical Problem; Must Generate Local Temperature That Approximate those found in STARS • 40 Years of Intense Study Have NOT Even Reached the Energy Break-Even Point

13. Energy Summary • In My Humble Opinion ENERGY PRODUCTION is the SINGLE MOST IMPORTANT Technology Issue Facing Human Kind • A Low-Cost, Low-Environmental-Impact Energy Source GREATLY Facilitates The Solution of All Technical Problems • Food Production • Medical Advances • Water Production • Housing & Shelter

14. All Done for Today NationalIgnitionFacility Fusion in LIVERMORE