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% Nuclear 9% Hydro 3% Natural Gas 20% Petroleum 41% 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

H 2 O CO 2 Energy Lifecycle: Automobile

Energy Lifecycle: Automobile CO 2 H 2 O NO CO Energy (Transportation) X

Combustion Products

NO X + VOC + Sunlight = Ground Level Ozone CO 2 H 2 O

Combustion Products

C 8 H 18 + 12.5 (O 2 + 3.76 N 2 )



8 CO 2 + 9 H 2 O + 47 N 2 1 kmol fuel



8 kmol CO 2 1 kg fuel



3+ kg CO 2 One 16 gallon tank



320 lbs CO 2 U.S. CO 2 Emissions = 6.5 Billion Tons Worldwide CO 2 = 30 Billion Tons

Global CO

2

Concentrations

Data from Mauna Loa Observatory, Hawaii

Climate Change

Long Wavelength, Low Energy CO 2 11 of Last 12 Years Rank Among the 12 of the Warmest Since 1850 Average Temperature Risen 1.5



F Since 1900 Sea Levels Have Risen 7 inches in the Last Century CO 2

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 km 2

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 CO 2 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

Black Absorber (0-10



C Rise) Glass Flat Plate Collector (0-50



C Rise) Evacuated Heat Pipe (10-100



C Rise) Water Insulation Focused Collector (50-150



C Rise) Water

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

CO 2 CO 2 Low Temperature Heat

Bioenergy

CO 2 CO 2 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

 •

World’s Energy Consumption



95 TW 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

The Aerofoil

Wind Energy

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

Winds

Wave Energy

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 Whale A Few Other Ideas Frog Clam Swan Dragon

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 Ebb Generation



h Ocean Reservoir 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/m 2 Hot Springs Geothermal Plant Impermeable Rock 0.05 W/m 2 Steam Water Impermeable Rock Liquid Hot Magma Water Impermeable Rock

Geothermal Energy

Many Possible Configurations Steam Turbine Generator Electricity to Grid Flash Chamber Cooling Tower 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.