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Chapter 10

Chapter 10. Structure of the Utility Industry Managing Energy Demand Electrical Charges and Currents Batteries and Electric Vehicles Hybrid Vehicles Ohms Law. Energy in the News. Electrical Generation vs Time. Sources and amount of electricity generation in the United

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Chapter 10

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  1. Chapter 10 Structure of the Utility Industry Managing Energy Demand Electrical Charges and Currents Batteries and Electric Vehicles Hybrid Vehicles Ohms Law

  2. Energy in the News

  3. Electrical Generation vs Time Sources and amount of electricity generation in the United States from 1950 to 2000 (for units see figure 10.1 in your Book. Purple (top): coal Green: Petroleum and natural gas Aqua: Hydroelectric power Blue: Nuclear power.

  4. General Trends Coal provides most of the power for electrical generation Need for electrical power in the 1970s, doubled every 10 years Rate of growth in demand has slowed to about 2% per year (implied doubling time??) Energy use overall: largest rate of growth is in electrical consumption

  5. Use of Coal, Natural Gas and Petroleum by Utilities Nonutility producers of Energy: use proportionately more renewable energy, Don’t use nuclear at all. Do use some fossil fuels.

  6. Restructuring of the Utilities Deregulation of the utilities: Goals: 1) To make electricity cheaper by promoting competition 2) Promote increased efficiency of power plants 3) Allow consumers choice of renewable energy sources Historical Perspective: Why a utility monopoly? 1) Smoothing of demand: promotes efficiency 2) Power plants are expensive

  7. Utilities: Why Change? 1) Facilities already built 2) Profit guaranteed: no incentive for change 3) Power plant efficiencies: historical trends 4) Renewable energy sources (other than hydro)

  8. Deregulation History PURPA: Public Utility Regulatory Policy Act: 1978 1) Must buy power from independent producers at avoided cost (about 6 cents per kWH), typical cost of electricity from existing Power plants (about 3.5 cents per kWH). Avoided cost: cost of constructing new power plants Cost of wind generated power: about 5.5 cents per kWh Cogeneration: typically cheaper than wind power Result: promotion of cogeneration and wind power: Increased energy efficiency and renewable power.

  9. Problems with Deregulation Stranded costs Utilities divided up: Generation, transmission and distribution all separate If a utility sells a power plant: who should get the profits? California: regulated charges from utilities to consumers But not charges from fossil fuel brokers to utilities Transmission lines: incentive to modernize?

  10. Good Aspects of Deregulation Number of independent power producers increased, Therefore more power generated from renewables Efficiency of power plants now increasing rather Than stalling; newer plants 40% efficient Could be 60% efficient with best technology Consumers in some states can choose to pay more To buy power generated from renewables: Increases the market for renewables

  11. Energy Trends Times of high demand: electrical costs $10 per KWH Vs typical price? Peak power use closer and closer to total capacity Big plants no longer most efficient power generators: New technologies like microturbines important Transmission lines: need modernization (What happened in California power crisis?) Times of high demand: utilities pay big energy users To shut down. (What types of companies use the most power?)

  12. Electrical Charges and Currents Electricity= moving electrons Conductors: metals with electrons able to move easily (outer shell of electrons in the atom) Electron: negative charge Proton: positive charge Unit of Charge: coulomb 6.25E18 electrons = 1 Coulomb Like charges repel: unlike charges attract

  13. Semi-Conductors and Insulators Semi-conductors: electricity is conducted but less Easily than in conductors (What uses semi-conductors?) Insulators: don’t conduct electricity. PCBs are insulators PCB = polychlorinated biphenols Hudson river and PCBs Why did General Electric manufacture PCBs in large amounts?

  14. Electrical Force Potential Energy: Applies to electrical force Electrical Potential= Potential energy embodied In electrical charges: unit of potential = volt One volt = 1 Joule per Coulomb Potential Difference: Electrical potential energy Derived from difference in energy between positively And negatively charged parts of electrical device Electrical current flows from negative to positive Why??

  15. Electrical Current Electrical current: movement of electrons from Area of electron excess (negative charge) to Area of electron deficit (positive charge) Unit of current= amp or ampere Types of current: direct current (DC) Alternating current (AC) Alternating current: has a frequency in hertz (Hz) USA: 60 Hz Europe: 50 Hz Most devices run on AC because generators produce AC Solar homes run on DC (why?)

  16. Battery Driven Electrical Motor Where is the circuit In this picture? What do you need to Know to determine The direction of Current flow?

  17. Batteries Inside of a flashlight with two batteries: Where is current flowing in this device? In what part is current flowing to the right? In what part is current flowing to the left?

  18. Components of a Battery 1)Two electrodes (or terminals) 2) Submerged in an electrolyte Electrolytes allow a chemical Reaction to occur. This chemical energy is converted Into electrical energy by the Battery Do batteries get warmer when they operate: why or why not? Pb-acid Dry Cell

  19. Pb-acid batteries Chemical reactions: Negative electrode Pb= Pb 2+ +2e- Pb2++SO4 2- = PbSO4 Positive electrode: PbO2 PbO2 + SO4 2- , 4H+ + 2e- = PbSO4 + 2H20 Electrolyte is providing H+ and SO4 2- Both are needed for the chemical reaction Where does PbSO4 end up? Pb acid battery: car battery stores about 2% of the energy in 1 gallon Of gasoline (seismometers in Iceland)

  20. Important Battery Characteristics Overall voltage Battery Life Rechargable? Energy Density (Watt hours per kilogram) Toxicity of components

  21. Battery Design First battery: invented by Volta Zinc and Silver plates Blotting paper moistened with Salt water. What are the electrodes? What is the electrolyte? What compounds are being formed? (Make an educated guess)

  22. Lemon Power Runs a Calculator Why does this work? What part of the battery are The lemons functioning as? What else needs to be Present?

  23. Battery Characteristics (for electric cars) What is the range derived from? Why don’t the batteries with The highest energy density always have the greatest range?

  24. Types of Batteries Range is for an electrical car with that battery. Why doesn’t the Battery with the highest energy density have the largest range?

  25. Electrical Vehicles Not new: first speeding ticket for a car-given to An electrical car (how fast was it going?) Electric powered vehicles (Evs) Mostly powered by Pb acid batteries Batteries take 6 to 8 hours to recharge Range of 60 to 160 miles between charges (sound too short a distance? 75% of private cars Are driven less than 50 miles per day)

  26. How an Electrical Vehicle Works

  27. Electrical Vehicles:Why? Big incentive: California law requiring that 10% of all new cars sold in California be zero emission vehicles (ZEVs) by 2003. Only two types of zero emissions vehicles: bicycles and electrical cars Are there zero emissions of CO2 when an electrical Car is used? Why or why not?

  28. Electrical Cars: Pros and Cons Against: are not truly zero emissions vehicles Emissions are just moved to the power plant Pb acid batteries: production and use generate Pb Pollution-so far other batteries much too expensive At present power plant efficiencies overall level of pollution Produced by electrical cars: more than by hybrid cars Pro: as power plant efficiencies improve (60% possible) Electrical vehicles will outperform present hybrids In terms of overall emissions Reduce urban air pollution

  29. Hybrid Vehicles Hybrids are not just cars: a hybrid is any vehicle That uses two forms of energy for propulsion Name three types of hybrid vehicle.

  30. Two Hybrids on the Market Toyotas Prius: 52 mpg city, 45 mpg highway Hondas Insight: 61 mpg city, 70 mpg highway

  31. How Insight gets 70 mpg!!This is a new record!! Combination of electrical motor and gasoline engine: thus gasoline engine smaller, runs at maximum efficiency Gasoline engine shuts off at a stoplight Energy from braking used to charge the battery that runs the electrical motor. Unique aerodynamic design of car

  32. Emissions Reduction Insight emits 84% fewer hydrocarbons and 50% less NOx than a typical car. Note that the Prius gets better mileage in the City than on the highway. Why?

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