390 likes | 510 Views
Engineering 10. Chp.6 Future Challenges. Bruce Mayer, PE Licensed Electrical & Mechanical Engineer BMayer@ChabotCollege.edu. Energy & Humans. James Watt and His Predecessors (e.g., Savery & Newcomen ) FREED Human-Kind From Muscle Power
E N D
Engineering 10 Chp.6 FutureChallenges Bruce Mayer, PE Licensed Electrical & Mechanical EngineerBMayer@ChabotCollege.edu
Energy & Humans • James Watt and His Predecessors (e.g., Savery & Newcomen) FREED Human-Kind From Muscle Power • The Heat Engine Was One of the Great Advances in Human History • Enabled the “Industrial Age” • The Generation & Application of Energy Multiplies The Capabilities of EVERY Person
Watt’s Engine Watt, James (1736-1819) Scottish inventor and mechanical engineer, renowned for his improvements of the steam engine. Watt was born on January 19, 1736, in Greenock, Scotland. He worked as a mathematical-instrument maker from the age of 19 and soon became interested in improving the steam engines, invented by the English engineers Thomas Savery and Thomas Newcomen, which were used at the time to pump water from mines.
Energy Sources • Let’s LIST Real And Potential Energy Sources OTHER Than Fossil Fuels • ? • ? • ? • ? • ? • ?
Energy Sources Fact & Fancy • Wind Power • Wind Turbines Are VERY Attractive • Energy Input to Produce is Low • Incremental Added Capacity • NO Emissions of Any Kind • Limitations • Low Energy Density • Must Cover Large Areas to Produce Much Energy • Limited Viable Sites • Balance of System Costs (AC→AC Freq Converter) • Danger to WildLife; Particularly Birds (Raptors)
Energy Sources Fact & Fancy • Split Wood, Not Atoms → BioMass • Burning Garbage or Plant Matter is Attractive • Simultaneous Solution to Energy and Solid-Waste Problems • “Renewable” Resource • Low Energy Input to Produce • Limitation: Emission Stream is VERY Unpleasant • Scrubbing Wood-Smoke is MUCH Harder than Cleaning Gasoline Combustion ByProducts
Glen Canyon Dam – Page, AZ • Electrical Power Generation • River: Colorado River • Plant Type: Conventional • Powerhouse Type: Above Gnd • Turbine Type: Francis • Original Nameplate Capacity: 950,000 kW (950 MWe) • Installed Capacity:1,304 MWe • Year of Initial Operation:1964 • Net Generation (FY 2005): 3,208,591,407 kWh • Rated Head:510 feet
Glen Canyon DamAerial View Lawn Generators Visitor Center Bridge TransmissionTowers TransformerSwitchYard
Glen Canyon Dam – Power Gen 150 rpm48 Poles
Glen Canyon Dam – Power Gen • Set-UP Transformers 13.8kV 230kVor 13.8kV 345kV
Energy Sources Fact & Fancy • HydroElectricPower • Fancy: Can Provide for Future Growth • Fact: Almost ALL Viable Hydro Sites Have Been USED • Damming More Rivers is a Political Issue • Ethanol as AutoMobile Fuel • Fancy: Ethanol Can Replace Oil As a Source for Automobile Fuel • Fact: Making Ethanol from Corn May Use MORE Energy than It Produces
Energy Sources Fact & Fancy • Ethanol Continued • DISTILLATION of Ethanol from Fermented Corn Requires Large Amounts of Energy • Usually Provided by Burning Fossil Fuels at the Distillation Site, or at the Electrical Power Plant • Solar PhotoVoltaics (solar cells) Can Supply Future Energy Needs • Photovoltaic Solar-Electric Cells Have Many Advantages • Remote Siting, Incremental Expansion
Energy Sources Fact & Fancy • Solar Cells Continued • BUT Making a Solar Cell Requires Large Amounts of Energy • Silicon Cells are Made by, in the Beginning, MELTING SAND • Production Processes Can be Energy Intensive as Well • Connecting to the Existing Electric Grid Includes a Great Deal of “Balance of System” Components • DC→AC “Inverters”, Special Electrical boxes
Energy Sources Fact & Fancy Proton Exchange Membrane (PEM) FC http://fuelcells.si.edu/basics.htm • Solar Cells Continued • Solar Radiation has a Very Low “Energy Density” • Requires LARGE Areas to Collect Significant Amounts of Energy • Can Crowd-Out Other Uses: Solar-Farm vs. Tomato-Farm • Hydrogen Fuel Cells • Based on Chemical Reaction See also http://www.olympusmicro.com/primer/java/fuelcell/
Energy Sources Fact & Fancy • Hydrogen Fuel Cells Continued • The Fuel Cell Reaction Looks Very Good • NO VOCs/HydroCarbon Emissions • NO NOx emission • NO Greenhouse Gases (CO2) • But WHERE Do We Get the HYDROGEN? • There are NO Hydrogen WELLS or MINES • The Viable Sources of Massive Amounts of Hydrogen themselves Require Large Energy or Carbon Inputs
Energy Sources Fact & Fancy • In Apr04 Gov. Arnold Schwarzenegger has proposed an ambitious network of hydrogen filling stations by 2010 • See also http://www.hydrogenhighway.ca.gov/ • But How can we MAKE all the Hydrogen needed to Replace Gasoline? • There are 3 Viable Alternatives
Energy Sources Fact & Fancy • Use WIND or NUCLEAR Power to generate Electricity which, in Turn, would be Used to Electrolize WATER • Electrolosis applies Electrical current to water and splits it into oxygen and hydrogen, which are then separated… • The Chemical Reaction • This is a Very Energy Intensive Process; about 75% efficient
Electric Cars: H2vsElectroChem Ulf Bossel, “Does a Hydrogen Economy Make Sense?”, Proceedings of the IEEE | Vol. 94, No. 10, October 2006, pp 1826-1837
Energy Sources Fact & Fancy • Steam reforming of natural gas • If you take methane, the main component of natural gas, and expose it to steam, the final products are primarily carbon dioxide and hydrogen. Chemically • This is already a Large-Volume Industrial Process, but it produces a LOT of CO2 – a GreenHouse Gas • Natural Gas Supplies seem ample
Energy Sources Fact & Fancy • Coal gasification • hydrogen could be produced at centralized plants, compressed and most likely transported in trucks. • Coal is mostly carbon & hydrogen, but also contains some sulfur. Exposed to water at high temperature and high pressure, it chemically reacts to yield carbon monoxide (CO) and hydrogen. • But CO is Poisonous to Humans
Energy Sources Fact & Fancy • Coal gasification, cont. • Oxygen from additional water vapor turns carbon monoxide into carbon dioxide. So the end products are primarily carbon dioxide and hydrogen gas. Chemically • We have LOTS of Coal, but still need to clean up the CO2 and H2S
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?
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
Electric Car Electricity Estimate • To Run our vehicles on Electricity we would need to open a NEW Nuclear PowerPlant EVERY MONTH for TEN YEARS
New Electricity for Cars Compared • The TOTAL generating Capacity in the USA is about 1 070 000 MWe • The Electricity for Cars would add about 25% to the USA total • The Total generating Capacity in CALIFORNIA is about 56 000 MWe • The Electricity for Cars would require about 4 NEW Californias
USA Primary Energy Production by Source http://www.eia.doe.gov/aer/overview.html * 2009
Energy BackWork Ratio • The BIG QUESTION for Any Energy Src • For Every Unit of Energy OUTput, How Much Energy was INput for the ENTIRE Production Stream? • In Electrical Power Generation, for the Steady-State Condition, this is called the “BackWork Ratio” • Many Energy Sources Fail This Question • e.g., Many Solar-Electric Systems will NOT Return the Energy Required to Make Them
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
All Done for Today California’sHydrogenHighWay There were 143 H2 vehicles in 2007