STEM Scholars Lecture on Sustainable Energy - California State ...

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22 févr. 2014 (il y a 3 années et 1 mois)

74 vue(s)

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

Hydro 3%
Nuclear 9%
Natural Gas 20%
Coal 24%
Petroleum 41%
Renewables 3%
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

H
2
O

CO
2

CO
2


NO
X

H
2
O


CO

Energy
(Transportation)

Energy Lifecycle: Automobile

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


㠠歭潬⁃8
2

1 kg fuel



3+ kg CO
2

One 16 gallon tank


㌲〠汢猠䍏
2

U.S. CO
2

Emissions = 6.5 Billion Tons

Worldwide CO
2

= 30 Billion Tons

Combustion Products

Global CO
2

Concentrations

Data from Mauna Loa Observatory, Hawaii

Climate Change

Long Wavelength,
Low Energy

11 of Last 12 Years Rank Among

the 12 of the Warmest Since 1850

Average Temperature Risen 1.5


卩湣n‱㤰0

卥愠䱥L敬猠䡡癥⁒楳敮‷⁩湣桥n⁩渠
瑨攠䱡t琠䍥湴畲n

CO
2

CO
2

Climate Change

So it’s a Little Warmer,

What’s the Big Deal?


1.

Avg. Temp. to Increase 3 to 9


䘠批b㈱〰




佣敡湳n瑯t剩獥‷ 瑯t㌱⁉湣桥h 批b㈱〰



䵯牥 䙲敱略湴n慮搠却牯湧敲S䡵牲楣慮敳



䕸瑲敭攠e敡瑨敲



䕣潳祳瑥浳 慮搠䡡扩瑡琠䱯獳



䝬慣楥爠剥瑲敡琠



䕣潮潭楣 䥭灡捴c

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

Active

Solar Collector, Rooftops

Passive


Integrating Low Energy Design


Solar Thermal

Domestic Hot Water

Pools/Spas

Residential Space
Heating

Adsorption
Refrigeration

Industry/Processing

Solar Collectors

Water

Black Absorber

(0
-
10

䌠剩獥C

䙬慴F偬慴攠䍯汬散瑯e


-
㔰5

䌠剩獥R

䝬慳a

Insulation

Evacuated Heat Pipe

(10
-
100

䌠剩獥R

W慴ar

䙯捵獥搠䍯汬散e潲

⠵(
-
ㄵ〠

䌠剩獥R

Solar Collectors

Evacuated Heat Pipe Water Heater

Passive Solar Heating

Warm

Cool

Trombe Wall

Conservatory

Warm

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


CO
2

Heat and Electricity

CO
2

Bioenergy

CO
2

Low Temperature
Heat

CO
2

Respiration

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)

Abengoa Bioenergy Facility in York County, Nebraska

Ethanol Production Capacity: 50 Million Tons per Year

Biofuels: Ethanol

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

Bioenergy Summary

Sun Heats Earth Unevenly


Buoyancy


Regional Pressure Differences


Wind Energy

Ocean

Land

Wind

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

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

Wind Energy Summary

Wave Energy

Winds

Turbulent Air Flow

Wind Flow on Upwind
Wave Faces

Shear Stress on
Surface of Water

Solar Radiation


W楮搠


W慶敳

W慶攠卩穥z䙡F瑯牳

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

Maximum Gravitational
Force: High Tide

Gravitational Force


Proportional to Mass of Earth, Moon


Inversely Proportional to Distance Squared

Minimum Gravitational Force

Tidal Energy

Minimum Centrifugal Force

Centrifugal Force


Earth
-
Moon System


“Spinning Through Space”

Maximum Centrifugal Force: High Tide

Center of
Mass

Tidal Energy

Ocean

Reservoir

Flood Generation

Ocean

Reservoir

Ebb Generation


h


h

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

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

Independent of the Sun

Radioactive Isotopes, Gravitational Energy

Geothermal Energy

340 W/m
2

Impermeable
Rock

Impermeable
Rock

Liquid Hot Magma


Water

0.05 W/m
2

Impermeable
Rock

Steam

Water

Hot
Springs

Geothermal
Plant

Many Possible Configurations


Geothermal Energy

Flash
Chamber

Cooling
Tower

Generator

Steam
Turbine

Heating,
Processing

Electricity
to Grid

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.