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Sustainable Energy: Challenges and Solutions STEM Scholars Lecture Series California State University Sacramento February 27, 2007 Sustainability “Meeting the needs of the present without compromising the ability of future generations to meet their needs.” Criteria for Sustainable Energy: 1. Fuel Supply not Depleted with Use 2. Properties of Earth/Atmosphere Unaltered 3. No Significant Social Injustices Energy Supply Renewables 3% Hydro 3% Nuclear 9% Petroleum 41% Natural Gas 20% Coal 24% 320,000,000,000 Gallons of Petroleum 1,000,000,000 Tons of Coal 22,000,000,000,000 Cubic Feet Natural Gas 36% Imported (Petroleum and Natural Gas) 85% From Fossil Fuels Energy Lifecycle: Automobile H2O CO2 Energy Lifecycle: Automobile CO2 NOX H2O CO Energy (Transportation) Combustion Products NOX + VOC + Sunlight = Ground Level Ozone CO2 H2O Combustion Products C8H18 + 12.5 (O2 + 3.76 N2) 8 CO2 + 9 H2O + 47 N2 1 kmol fuel 8 kmol CO2 1 kg fuel 3+ kg CO2 One 16 gallon tank 320 lbs CO2 U.S. CO2 Emissions = 6.5 Billion Tons Worldwide CO2 = 30 Billion Tons Global CO2 Concentrations Data from Mauna Loa Observatory, Hawaii Climate Change Long Wavelength, Low Energy CO2 11 of Last 12 Years Rank Among the 12 of the Warmest Since 1850 Average Temperature Risen 1.5F Since 1900 Sea Levels Have Risen 7 inches in the Last Century CO2 Climate Change So it’s a Little Warmer, What’s the Big Deal? 1. Avg. Temp. to Increase 3 to 9 F by 2100 2. Oceans to Rise 7 to 31 Inches by 2100 3. More Frequent and Stronger Hurricanes 4. Extreme Weather 5. Ecosystems and Habitat Loss 6. Glacier Retreat 7. Economic Impacts Climate Change February 2002 March 2002 Larsen B Ice Shelf – 200 m thick, 3200 km2 Climate Change February 17, 1993 February 21, 2000 Receding Snows of Mount Kilimanjaro, Tanzania, Africa Expected to Be Gone By 2020 Image courtesy of the Image Science & Analysis Laboratory, NASA Johnson Space Center Sociopolitical Injustices? Photos courtesy of Associated Press and Emirates Palace, Abu Dhabi Fossil Fuel Sustainability Depleting Fuel Reserves • Best Estimate: 40-80 years • Undiscovered Reserves Uncertain • Proven Reserves Uncertain (OPEC) • What is Certain? • Demand Increasing • Supply Decreasing Atmospheric CO2 Concentration Increasing Economic, National Security Issues Renewable Technologies Renewable Technologies • Direct Solar Thermal and PV • Indirect Solar • Biomass • Wind • Wave • Other Sources • Geothermal • Tidal Solar Thermal Active –Solar Collector, Rooftops Passive – Integrating Low Energy Design Domestic Hot Water Pools/Spas Residential Space Heating Adsorption Refrigeration Industry/Processing Solar Collectors Flat Plate Collector (0-50 C Rise) Black Absorber (0-10C Rise) Glass Water Evacuated Heat Pipe (10-100 C Rise) Water Insulation Focused Collector (50-150 C Rise) Solar Collectors Evacuated Heat Pipe Water Heater Passive Solar Heating Conservatory Trombe Wall Warm Warm Cool Outside Air Solar Photovoltaic Antireflective Coating + + + + + - - n-type Semiconductor p-type Semiconductor Backing Solar Summary Benefits • Simplicity • Availability vs. Demand: Peak-Summer • Cost-effectiveness Challenges • Intermittent and Little Availability in Winter • Energy, Cost of PV Cell Production What’s Next? • Widespread Use • New PV Applications (Thin Film, Flexible) Bioenergy Biomass – All of the Earth’s Living Matter Biofuels – Fuels Derived from Biomass Respiration Bioenergy CO2 CO2 CO2 Low Temperature Heat CO2 Heat and Electricity Bioenergy Traditional – Combustion of Raw Biomass “New” – Transform Properties (Liquid, Gas) • Utilize Waste and Replace Fossil Fuels • Reduce Pollutant Emissions Examples • Woody Crops – Forestry • Agricultural – Switch Grass, Corn, Oil Seeds • Wastes • Agricultural (Rice Husks, Corn Shucks, etc) • Animal (Dairy, Sewage) • Commercial (Sawdust, Tires, Landfill Gas) Biofuels: Ethanol Abengoa Bioenergy Facility in York County, Nebraska Ethanol Production Capacity: 50 Million Tons per Year Bioenergy Summary Benefits • Availability • World’s Biomass Energy Storage 95 TW • World’s Energy Consumption 15 TW • Existing Equipment, Infrastructure • Waste Utilization, Potentially Carbon Neutral • Scheduling Control Challenges • Energy Balance and Economics • Improve “New” Biofuel Processes • Increase Production Capacity Wind Energy Sun Heats Earth Unevenly • Buoyancy • Regional Pressure Differences Wind Ocean Land Wind Energy The Aerofoil Wind Turbines • Lift and/or Drag Forces in Direction of Rotation • Vertical or Horizontal Axis • Most Common: 3-Bladed, Horizontal Axis • Typical Efficiencies: 20-30% Wind Energy Wind Turbines or Bird Blenders? Avian Deaths (U.S. per Year) • • • • • • • Wind Turbines: 30,000 Communications Towers: 40 Million Pesticides: 67 Million Vehicles: 70 Million Cats: 100 Million Utility Lines: 150 Million Windows: 500 Million Altamont: Location, Tower Design, Spacing Wind Energy SMUD Solano Wind Project, Rio Vista, CA Wind Energy Summary Benefits • Economical • High Initial Investment • Low Maintenance, No Fuel Costs • Minimal Air, Water, Land Pollution • Scalability (1 kW to 3 MW) • Many “Good” Locations Challenges • Visual Pollution • Intermittency and Predictability Wave Energy Winds Turbulent Air Flow Shear Stress on Surface of Water Wind Flow on Upwind Wave Faces Solar Radiation Wind Waves Wave Size Factors 1. Wind Speed 2. Wind Duration 3. Distance Over Which Wave Travels Wave Energy Oscillating Water Column (OWC) Wave Energy The 500 kW LIMPET OWC, New Zealand Wave Energy Pelamis (Sea Snake) Hydraulic Rams Pump High Pressure Fluid Accumulated Fluid Drives Turbines, Generators A Few Other Ideas Whale Frog Dragon Clam Swan Wave Energy The 750 kW Pelamis Wave Energy Converter, Portugal Wave Energy Benefits • • • • • Waves = Concentrated Solar Energy Demand in Phase with Availability (Winter) Low/No Chemical Pollution Low Visual Pollution (Offshore) Large Potential Resource (Estimated 2 TW) Challenges • Electricity Transmission • Immature Technology • Potential Shipping, Boating Accidents Tidal Energy Gravitational Force • Proportional to Mass of Earth, Moon • Inversely Proportional to Distance Squared Minimum Gravitational Force Maximum Gravitational Force: High Tide Tidal Energy Centrifugal Force • Earth-Moon System • “Spinning Through Space” Center of Mass Minimum Centrifugal Force Maximum Centrifugal Force: High Tide Tidal Energy Large Generating Capacity (Many MW) Two Large 3.0 to 5.0 Hour Bursts per Day Four Smaller 1.5-3.0 Hour Bursts per Day Flood Generation h Ocean Reservoir Ebb Generation h Ocean Reservoir Tidal Energy Tidal Barrage at La Rance, France 240 MW Capacity 333 m Long 8 m Tidal Range Tidal Energy Benefits • Tremendous Electricity Generation Potential • No Green House Gas, Pollutant Emissions • Predictable Challenges • Environmental Impact • Modifying Water Levels Behind Dam • Less Variation, Affecting Birds and Fish • Shipping, Boating • Tremendous Initial Cost • Intermittency Geothermal Energy Independent of the Sun Radioactive Isotopes, Gravitational Energy 340 W/m2 0.05 W/m2 Hot Springs Geothermal Plant Steam Water Water Impermeable Rock Impermeable Rock Liquid Hot Magma Impermeable Rock Geothermal Energy Many Possible Configurations Steam Turbine Generator Electricity to Grid Cooling Tower Flash Chamber Heating, Processing Geothermal Energy One of twenty-one plants at the Geysers, Sonoma and Lake Counties, CA The Geysers Provides 850 MW to Power about 750,000 Homes Geothermal Energy Benefits • No Intermittency • Low/Zero Pollutant Emissions Challenges • Source Depleted (Energy Mining) • 250:1 Use to Recharge Rate • Limited Sources • High Quality Sources Tapped • Most Near Tectonic Plate Interfaces • Better Utilize Low Quality Sources • Ground Source Heat Pump How do we get Sustainable? As Citizens • Reduce, Reuse, Recycle • Drive a Fuel Efficient Car • Don’t Drive (Telecommute, Public Trans) • Make Your Home Energy Efficient • Insulation, Caulking and Door Seals • Tune Heater and Air Conditioner • High Efficiency Appliances and Lights • Install Renewables • Plant Trees How do we get Sustainable? As Scientists, Engineers and Mathematicians • Traditional Technologies • Efficient Gasoline and Diesel Vehicles • Cogeneration and Carbon Sequestration • Energy Efficiency and Management • Research, Develop Emerging Technologies • New Biofuel Sources • Fuel Cells and Hydrogen • New Technologies and Applications • Bring Sustainable Products to Market • Transparent, Cost Effective Sacramento State Expertise Solar Thermal • Solar Heating and Adsorption Refrigeration • Efficient Building Design Biofuels and Combustion • Conversion of Biomass to Alcohol Fuels • Mesoscale and Distributed Power Systems • Ultra-Low Emissions Combustion Stationary Power Fuel Cells • New Fuel Cell Types • Parametric Study and Computer Simulation Clean Energy Center Internal – Student Learning through Research External – Regional Clean Energy Growth Mission: Contribute to Sustainable Energy in the Sacramento Region with Education and Research Goals • Promote Collaboration within Sac State • Foster External Relationships • Facilitate External Funding and Publication • Create Authentic Learning Experiences • Provide Technical Expertise to Startups Photo Credits John Gilardi SMUD General Motors NASA Emirates Palace Solar Innovations, Inc Abengoa Bioenergy Wavegen: Voith Siemens Hydro Power Generation Ocean Power Delivery, Ltd. Icelandic National Energy Authority Calpine, Corp.