geothermal, hydro and ocean energy; energy storage/ hydrogen economy · pdf filea.shakouri, 19...

A.Shakouri, 19 Sept. 2008 1

Geothermal, Hydro and Ocean Energy;

Energy Storage/ Hydrogen Economy

Ali ShakouriBaskin School of Engineering

University of California Santa Cruzhttp://quantum.soe.ucsc.edu/

LoCal-RE, UC Santa Cruz; 30 July 2009

Geothermal Energy Potential

• Advantages: very high efficiency; low initial costs since you already got steam

• 200C at 10km depth• Disadvantages: non-

renewable (more is taken out than can be put in by nature); highly local resource

• 1985: $0.15/kWh• 2002: $0.05-0.08 /kWh

A.Shakouri, 19 Sept. 2008 2http://www.eere.energy.gov/


Two well enhanced geothermal system

Tester et al., Phil Trans. R. Soc. A 2007

Geothermal Energy Potential

• Mean terrestrial geothermal flux at earth’s surface 0.059 W/m2

• Total continental geothermal energy potential 11.6 TW• Oceanic geothermal energy potential 30 TW

• Wells “run out of steam” in 5 years• Power from a good geothermal well (pair) 5 MW• Power from typical Saudi oil well 500 MW• Needs drilling technology breakthrough

(from exponential $/m to linear $/m) to become economical)

A.Shakouri, 19 Sept. 2008 4Nate Lewis, Caltech

Some renewable energy solutions

Geothermal


Hydroelectric

Ocean

Hydro Power

• Advantages: No pollution; Very high efficiency (80%); little waste heat; low cost per KWh; can adjust KWh output to peak loads; recreation dollars

• Disadvantages: Fish are endangered species; Sediment buildup and dam failure; changes watershed characteristics; alters hydrological cycle

A.Shakouri, 19 Sept. 2008 6http://zebu.uoregon.edu/2001/ph162/l1.html

Hydroelectric Energy Potential


Globally

• Gross theoretical potential 4.6 TW• Technically feasible potential 1.5 TW• Economically feasible potential 0.9 TW• Installed capacity in 1997 0.6 TW• Production in 1997 0.3 TW

(can get to 80% capacity in some cases)Source: WEA 2000

Nate Lewis, Caltech

Energy from Ocean

• Advantages: large energy flows; steady flow for decades;

• Disadvantages: Enormous engineering effort; Extreme conditions (corrosion, storm, transmission); Extremely high cost; Damage to coastal environments?


Tidal Energy Conversion

Rance, France

A.Shakouri, 19 Sept. 2008 9Kerr, Phil Trans. R. Soc. A 2007

Tidal Projects


World Annual Mean Wave Energy

kW/m


Wave Energy Conversion Devices


UK Wave Energy Assessment


A.Shakouri, 19 Sept. 2008 15Roger Bedard, EPRI


University of California Santa CruzElectrical Engineering Department

Energy Storage and Hydrogen Economy

Ali Shakouri

EE80J-180J; 21 May 2009

Electricity Usage Pattern


Energy Usage in a typical household

Electricity Usage ~15 kWh/day (54 MJ/day) power ~ 625W

Storage:

•Water: 78,717 liter (4.3 m3) at 100 meter (70% conversion efficiency)

•Flywheel: 2138kg, 4m radius, 600rpm (80% conversion efficiency)

•Compressed Air: 3600 liter (0.03 MJ/liter, 50% conversion efficiency)

Hot Water Usage ~25-35MJ150-200 liter water heated from 15C up to 55C

•Burn 4-5kg of wood in 50% efficient wood stove.


Energy Storage Options


Energy Storage Options


Specific Energy (Wh/kg)

Spe

cific

Pow

er (W

/kg)

Combustion Engine

Basic Research Needs for the Hydrogen Economy

June 24, 2004DOE Nano SummitWashington, D.C.

Presented by: Mildred Dresselhaus

Massachusetts Institute of [email protected]

617-253-6864


Hydrogen: A National Initiative in 2003Hydrogen: A National Initiative in 2003

“Tonight I'm proposing $1.2 billion in research funding so that America can lead the world in developing clean, hydrogen-powered automobiles… With a new national commitment, our scientists and engineers will overcome obstacles to taking these cars from laboratory to showroom, so that the first car driven by a child born today could be powered by hydrogen, and pollution-free.”

President Bush, State-of the-Union Address, January 28, 2003

A.Shakouri, 19 Sept. 2008 27M. S. Dresselhaus, MIT

The Hydrogen Economy

H2Oautomotivefuel cells

solarwindhydro

stationaryelectricity/heat

generation

consumerelectronics

gas orhydridestorage

fossil fuelreforming

nuclear/solar thermochemical

cyclesH2 H2

Bio- and bioinspired

production storage use in fuel cells

9M tons/yr

150 M tons/yr(light cars and trucks in 2040) 9.70 MJ/L

(2015 FreedomCAR Target)

4.4 MJ/L (Gas, 10,000 psi)8.4 MJ/L (Liquid H2)

$3000/kW

$30/kW(Internal Combustion Engine)


Fundamental IssuesFundamental Issues

The hydrogen economy is a compelling vision:- It potentially provides an abundant, clean, secure and flexibleenergy carrier- Its elements have been demonstrated in the laboratory or in prototypes

However . . . - It does not operate as an integrated network- It is not yet competitive with the fossil fuel economy in cost,performance, or reliability- The most optimistic estimates put the hydrogen economy decades away

Thus . . . - An aggressive basic research program is needed, especially in gaining a fundamental understanding of theinteraction between hydrogen and materials at the nanoscale


Hydrogen and Fuel Cells


• Hydrogen is the lightest and most abundant element in the universe.

– Found in water (H²O), biomass and fossil fuels – Can be produced from a variety of domestic fossil and

renewable resources using a variety of technologies• Fuel and electricity

– Fuel cells: Electrochemical devices that combine hydrogen and oxygen to produce electricity, heat, and water

– Fuel: Used as fuel in rocket engines and ICEs• Renewable R&D Focus

– Integrated wind/electrolysis systems, biomass-to-hydrogen process development, direct water splitting, advanced storage technologies, fuel cell development and demonstration

• Hydrogen can benefit renewables– Links renewable electricity to transportation– Storage medium for intermittant resources

• Power System Size Range– Fuel Cells: 1W -2MW (depending on type and

application-portable, transportation, stationary)• Hydrogen Production Cost

– Natural gas reforming: $1.67- $1.93/kg ($5.00/MMBtu natural gas; captive hydrogen; no compression or storage):

– Ideal electrolysis system: $3.00/kg (7.5¢ /kWh electricity cost; 100% efficiency; no compression or storage)Sources: EERE Hydrogen Website; SRI Chemical Economics Handbook,

(2002); Summary of Electrolytic Hydrogen Production (NREL 2004)

Photobiologicalhydrogen production

Measurement of hydrogen storage properties of advanced

solid materials

California fuel cell bus demonstration

Fuel cell testing in the lab

Keith WipkeNational Renewable Energy Laboratory

Fuel Cell Vehicle Learning Demonstration Project Underway; 3 Years into 5 Year Demo

• Objectives– Validate H2 FC Vehicles and Infrastructure in Parallel– Identify Current Status and Evolution of the Technology

Photo: NRELHydrogen refueling station, Chino, CA




Vehicle Status: All of First Generation Vehicles Deployed, 2nd Generation Initial Introduction in Fall 2007

On-Board Hydrogen Storage Methods

-

10

20

30

40

50

60

70

80

90

2005Q2 2005Q3 2005Q4 2006Q1 2006Q2 2006Q3 2006Q4 2007Q1 2007Q2

# of

Veh

icle

s (A

ll Te

ams)

Liquid H210,000 psi tanks5,000 psi tanks

Created Aug-28-2007 9:29PM

77


Hydrogen Production PanelHydrogen Production Panel

Current status:• Steam-reforming of oil and natural gas produces 9M tons H2/yr• We will need 150M tons/yr for transportation• Requires CO2 sequestration.Alternative sources and technologies:Coal:

• Cheap, lower H2 yield/C, more contaminants• Research and Development needed for process development, gas separations, catalysis, impurity removal.

Solar:• Widely distributed carbon-neutral; low energy density.• Photovoltaic/electrolysis current standard – 15% efficient• Requires 0.3% of land area to serve transportation.

Nuclear: Abundant; carbon-neutral; long development cycle.

Panel Chairs: Tom Mallouk (Penn State), Laurie Mets (U of Chicago)



Fossil Fuel Reforming Intermediate TermMolecular level understanding of catalytic mechanisms, nanoscale catalyst design, high temperature gas separation

Solar Photoelectrochemistry/PhotocatalysisLight harvesting, charge transport, chemical assemblies, bandgap engineering, interfacial chemistry, catalysis and photocatalysis, organic semiconductors, theory and modeling, and stability

Bio- and Bio-inspired H2 ProductionMicrobes & component redox enzymes, nanostructured 2D & 3D hydrogen/oxygen catalysis, sensing, and energy transduction, engineer robust biological and biomimetic H2production systems

Nuclear and Solar Thermal HydrogenThermodynamic data and modeling for thermochemicalcycle (TC), high temperature materials: membranes, TC heat exchanger materials, gas separation, improved catalysts

Priority Research Areas in Hydrogen Priority Research Areas in Hydrogen ProductionProduction

Dye-Sensitized Solar Cells

Ni surface-alloyed with Au to reduce carbon poisoning

Thermochemical Water Splitting

Synthetic Catalysts for H2 Production


Current Technology for automotive applications• Tanks for gaseous or liquid hydrogen storage. • Progress demonstrated in solid state storage materials.System Requirements• Compact, light-weight, affordable storage. • System requirements set for FreedomCAR: 4.5 wt% hydrogen for 2005, 9 wt% hydrogen for 2015. • No current storage system or material meets all targets.

Hydrogen Storage PanelHydrogen Storage Panel

Gravimetric Energy DensityMJ/kg system

Volu

met

ric E

nerg

y D

ensi

tyM

J / L

sys

tem

0

10

20

30

0 10 20 30 40

Energy Density of Fuels

proposed DOE goal

gasoline

liquid H2

chemicalhydrides

complex hydrides

compressed gas H2

Panel Chairs: Kathy Taylor (GM, Retired) and Puru Jena (Virginia Commonwealth U)

M. S. Dresselhaus, MIT

Carbon Carbon NanotubesNanotubes for Hydrogen Storagefor Hydrogen Storage

• The very small size and very high surface area of carbon nanotubes make them interesting for hydrogen storage. • Challenge is to increase the H:C stoichiometry and to strengthen the H—C bonding at 300 K.

A computational representation of hydrogen adsorption in an optimized array of (10,10) nanotubes at 298 K and 200 Bar. The red spheres represent hydrogen molecules and the blue spheres represent carbon atoms in the nanotubes, showing 3 kinds of binding sites. (K. Johnson et al)


Priority Research Areas in Hydrogen StoragePriority Research Areas in Hydrogen Storage

Metal Hydrides and Complex HydridesDegradation, thermophysical properties, effects of surfaces, processing, dopants, and catalysts in improving kinetics, nanostructured composites

Nanoscale/Novel MaterialsFinite size, shape, and curvature effects on electronic states, thermodynamics, and bonding, heterogeneous compositions and structures, catalyzed dissociation and interior storage phase

Theory and ModelingModel systems for benchmarking against calculations at all length scales, integrating disparate time & length scales, first principles methods applicable to condensed phases

Fuel PEFC

Fuel (NaBH4)

Spent fuel

Fuel CellVehicle

Fuel

Spent fuelrecovery(NaBO2)

Service Station

Borohydride Production

(Mg)

H2

(MgO)

Fuel PEFC

Fuel (NaBH4)

Spent fuel

Fuel CellVehicle

Fuel

Spent fuelrecovery(NaBO2)

Service Station

Borohydride Production

(Mg)

H2

(MgO)

NaAlH4 X-ray view NaAlD4 neutron viewNaAlH4 X-ray view NaAlD4 neutron view

H D C O Al Si Fe

X ray cross section

Neutron cross section

H D C O Al Si Fe

X ray cross section

Neutron cross section

NaBH4 + 2 H2O → 4 H2 + NaBO2

H Adsorption in Nanotube Array

Neutron Imaging of Hydrogen

Cup-Stacked Carbon Nanofiber


Fuel Cells

H2 + O2 → H2O + electrical energy


Fuel Cells and Novel Fuel Cell Materials Panel

Current status:Limits to performance are materials, which have not changed much in 15 years.

Panel Chairs: Frank DiSalvo (Cornell), Tom Zawodzinski (Case Western Reserve)


Challenges:Membranes

Operation in lower humidity, more strength,durability and higher ionic conductivity.

CathodesMaterials with lower overpotential and resistance to impurities.Low temperature operation needs cheaper (non- Pt) materials.Tolerance to impurities: S, hydrocarbons, Cl.

AnodesTolerance to impurities: CO, S, Cl.Cheaper (non or low Pt) catalysts.

ReformersNeed low temperature and inexpensive reformer catalysts.

power.com

membrane conducts protons from anode to cathProtonExchangeMembrane (PEM)Membrane conducts protons from anode toproton exchange membranepower.com

membrane conducts protons from anode to cathProtonExchangeMembrane (PEM)

power.com

membrane conducts protons from anode to cathProtonExchangeMembrane (PEM)

power.comProtonExchangeMembrane (PEM)Membrane conducts protons from anode to cathodeproton exchange membrane (PEM)

2H2 + O2 → 2H2O + electrical power + heat

M. S. Dresselhaus, MIT

Types of Fuel Cells

Alkaline Fuel Cell(AFC), Space Shuttle12 kWUnited Technologies

Solid Oxide FC(SOFC) 100 kWSiemens-

Westinghouse

Proton Exchange Membrane (PEM) 50 kW, Ballard

Molten Carbonate FC(MCFC) 250 kWFuelCell Energy,

Low-Temp

High Temp

Phosphoric Acid FC(PAFC), 250 kWUnited Technologies


Electrode/Membrane DesignVery challenging. Electrodes need to support three percolation networks: electronic, ionic, fuel/oxidizer/product access/egress.

2 –5 nm

20 -50 µm


Priority Research Areas in Fuel CellsPriority Research Areas in Fuel CellsElectrocatalysts and Membranes

Oxygen reduction cathodes, minimize rare metal usage in cathodes and anodes, synthesis and processing of designed triple percolation electrodes

Low Temperature Fuel Cells‘Higher’ temperature proton conducting membranes, degradation mechanisms, functionalizing materials with tailored nano-structures

Solid Oxide Fuel CellsTheory, modeling and simulation, validated by experiment, for electrochemical materials and processes, new materials-all components, novel synthesis routes for optimized architectures, advanced in-situ analytical tools

Source: H. Gasteiger (General Motors)

Mass of Pt Used in the Fuel Cell ⎯ a Critical Cost Issue

1.4

1.2

1

0.8

0.6

0.4

0.2

0

g Pt/k

W

Ecell (V)0.55 0.60 0.65 0.70 0.75 0.80

2-5 nm

20-50 -µm

Controlled design of triple percolation nanoscalenetworks: ions, electrons, and porosity for gases

YSZ Electrolyte for SOFCs

Porosity can be tailored

Internal view of a PEM fuel cell

H2Intake Anode Catalysts Cathode O2Intake

Electrons Water

Membranes

Source: T. Zawodzinski (CWRU)

Source: R. Gorte (U. Penn)


High Priority Research Directions for High Priority Research Directions for Hydrogen EconomyHydrogen Economy

• Low-cost and efficient renewable (solar) energy production of hydrogen

• Nanoscale catalyst design• Biological, biomimetic, and bio-inspired materials and

processes • Complex hydride materials for hydrogen storage• Nanostructured / novel hydrogen storage materials• Low-cost, highly active, durable cathodes for low-

temperature fuel cells• Membranes and separations processes for hydrogen

production and fuel cells


MessagesMessages

http://www.sc.doe.gov/bes/hydrogen.pdf

Enormous gap between present state-of-the-art capabilities and requirements that will allow hydrogen to be competitive with today’s energy technologies

production: 9M tons ⇒ 150M tons (vehicles)

storage: 4.4 MJ/L (10K psi gas) ⇒ 9.70 MJ/Lfuel cells: $3000/kW ⇒ $30/kW (gasoline engine)

Enormous R&D efforts will be requiredSimple improvements of today’s technologieswill not meet requirementsTechnical barriers can be overcome only with high risk/high payoff basic research

Research is highly interdisciplinary, requiring chemistry, materials science, physics, biology, engineering, nanoscience, computational science

Basic and applied research should couple seamlessly


Some Useful ReferencesSome Useful References

Basic Research Needs for the Hydrogen Economy (DOE/BES)http://www.sc.doe.gov/bes/hydrogen.pdf

Basic Research Needs to Assure a Secure Energy Future (DOE/BES) http://www.sc.doe.gov/bes/besac/Basic_Research_Needs_To_Assure_A_Secure_Energy_Future_FEB2003.pdf

Powering the Future - Materials Science for the Energy Platforms of the 21st Century: The Case of Hydrogen (MIT lecture notes)http://web.mit.edu/mrschapter/www/IAP/iap_2004.html

Hydrogen Programs (DOE/EERE) http://www.eere.energy.gov/hydrogenandfuelcells/

National Hydrogen Energy Roadmap (DOE/EERE)http://www.eere.energy.gov/hydrogenandfuelcells/pdfs/national_h2_roadmap.pdf

FreedomCAR Plan (DOE/EERE)http://www.eere.energy.gov/vehiclesandfuels/

Fuel Cell Overview (Smithsonian Institution)http://fuelcells.si.edu/basics.htm

The Hydrogen Economy: Opportunities, Costs, Barriers, and R&D Needs (National Research Council Report, 2004)http://www.nap.edu/books/0309091632/html/


geothermal, hydro and ocean energy; energy storage/ hydrogen economy · pdf filea.shakouri, 19...

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