Transcript Slide 1

Worldwide energy stats
• Total energy consumption:15 TW (1012) in
2004 (86.5 % from fossil fuels)
• This corresponds to 5·1020 J/yr
• Worldwide reserves of fossil fuels 4000·1020 J (800 yrs)
• 2.5·1024 J of uranium reserves
• Renewable energy flux from the sun
(radiation, wind, waves) 120 PW (1015) or
3.8·1024 J/yr
Energy Consumption Breakdown
Fuel type
Power (TW)
Energy (1018 J/yr)
%
Oil
5.6
180
38
Gas
3.5
110
24
Coal
3.8
120
26
Hydroelectric
0.9
30
6
Nuclear
0.9
30
6
0.13
4
0.9
14.83
474
100
Geo, wind, solar, wood
Total
EERE funded by DOE $2.3 B
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Biofuels ($235 M)
Batteries ($200 M)
Fuel Cells ($68 M)
Hydrogen (cut from 2010 budget, considered too long
term)
Solar cells ($320 M)
Wind ($75 M)
Water/Geothermal ($30 M / $50 M)
Green Buildings ($237 M)
Financing for states, industry and consumers to
encourage adoption ($350 M)
Nuclear ($845 M /$191 for Gen IV)) Office of Nuclear
energy
Fusion ($421 M) Office of Science ($4.9 B)
Potential for solar
• A land mass of about 100x100 miles in the
Southwest U.S.-less than 0.5% of the U.S.
mainland land mass, or about 25% of the
area currently used for the nation's
highway/roadway system-could provide as
much electricity as presently consumed in
the United States.
• Truly renewable, with a net positive energy
• Can be converted into electricity
Solar cells
• For use at site of power use
• Integration of solar energy into the electrical grid
• Semi-conductor
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Absorb photon
Excite electron into conduction band
Mobile electron holes
directional flow of electrons
An array of solar cells produce a usable quantity of
direct current (DC)
– Store the charge that is produced
n-doped Si (electron rich) and p-doped Si (electron poor)
Types of solar cells
• Wafer- based crystaline silicon
– Mono vs. poly (less efficient, but cheaper)
• Thin film Si – more flexible, lighter
• Cadmium telluride (Cd/Te) solar cell – easier to
deposit/large scale production
• Cu/In/Ga
• Organic polymer cells (low cost, large scale
production and flexibility, poor efficiency)
• Sensitized Solar cells (Grätzel cells); semiconductor formed between photo-sensitized
anode and an electrolyte
Performance
• Efficiency (5-20 %)
• Manufacturing cost (materials and
methods)
• Net Energy Analysis (Break even in 1-7
yrs depending on solar cell)
• Trade-off between efficiency and cost
Additional factors
• Solar concentrators (use a large area of
lenses or mirrors to focus sunlight on a
small area of photovoltaic cells)
– 400 suns
– 300 times reduction of materials
• Inverters and grid integration
– One way to two way grids that communicate
Table 2.1–3 Technical Barriers in Photovoltaics
Photovoltaic Technical Barriers
Modules
A. Material Utilization & Cost
B. Design & Packaging
C. Manufacturing Processes
D. Efficiency
Inverters & Other BOS
E. Inverter Reliability & Grid Integration
F. Energy Management Systems
G. BOS Cost & Installation Efficiency
Systems Engineering & Integration
H. Systems Engineering
I. Modularity & Standardization
J. Building-integrated products
2015 Goal
• PV-produced electricity and domestic
installed PV generation capacity of 5-10
GW
• 1000 GW/yr of electricity in US
• Much more long term
Concentrating Solar Power
(CSP) technologies
• Large scale electricity plants in the
Southwest US
• CSP plants produce power by first
converting the sun’s energy into heat, next
into mechanical power, and lastly, into
electricity in a conventional generator.
• Thermal storage (molten salt) or hybrid
natural gas system
Nuclear Energy
• How does a nuclear reactor work?
• Is it a major energy source worldwide?
• Problems
– Waste Disposal
– Accidents
• Future
– Research
– Generation IV
Nuclear Energy Plant
• Nuclear Fission
• 235U + n → 236U → 92Kr + 141Ba + g + 3n
• Chain Reaction
• Controlled by control (graphite) rods and water
coolant
• Heat from reactor is cooled by circulating
pressurized water
• Heat exchange with secondary water loop
produces steam
• Steam turns turbine generator to produce
electricity
Present Nuclear Energy
• 100 plant produce about 20 % of the
electricity in US
• 431 plants worldwide in 31 countries
produce about 17 % of the world’s
electricity
• Environmental Impact
– No Greenhouse gases
– Completely contained in normal operation
– Spent fuel issue
Waste Disposal
• Waste kept at plant, but running out of
room.
• Site chosen in Nevada for nuclear waste.
• Research on safe transportation
• Nuclear proliferation; fuel is very dilute and
not easily converted to weapons grade
• Stored in very heavy casings (difficult to
steal)
Accidents
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Nuclear Meltdown
Chernobyl
Three Mile Island
Environmentalist watch dogs note other
near misses in recent years
Chernobyl (1986)
• A planned test gone horribly wrong
• The test
– See if turbine generator could power the water pumps that cool
the reactor in the event of a loss of power
– Crew shut off power too rapidly, producing a Xe isotopes that
poisons the reactor
– In response the rods were lifted to stimulate reaction
– The lower cooling rate of the pumps during the experiment led to
steam buildup that increase reactor power
– Temperature increased so rapidly, that rod insertion could not be
performed in time to stop meltdown
– Roof blew off, oxygen rushed in a caused fire that spread
radioactive material over a large area
Blame
Management communication
A bizarre series of operator mistakes
Plant design, poor or no containment vessels
Large positive void coefficient (steam bubbles in
coolant)
Poor graphite control rod design
Poorly trained operators
Shut off safety systems
Helicopter drops
Coverup
Consequences
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Deaths of plant and workers
Medical problems (short and large term)
Thyroid cancer
Contaminated soil as far as Great Britain
Billions of $
Three Mile Island
• Partial meltdown
• No radiation escaped
• Caused fear of nuclear power and cost $
in terms of clean up
• Operator error and lack of safety backups
in design
• In some ways the accident showed how
the kind of catastrophic disaster at
Chernobyl is avoidable
types
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Generation I – retired; one of a kinds
In operation Gen II and Gen III
Gen II was a large design changes
Gen III and Gen II, upgraded with many
safety features along the way
• Gen III plus (passive safety systems)
• Gen IV, 30 yrs away
Gen IV
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Very High Temperature Reactor
Advance Nuclear Safety;
Address Nuclear Nonproliferation and
Physical Protection Issues;
Are Competitively Priced
Minimize Waste and Optimize Natural
Resource Utilization
Compatible with Hydrogen Generation
Gen IV Roadmap - 2002
• Solicited design models
• Chose six design models to base future
research
• Out of these six, the DOE has relatively
recently selected two for further
investment
– Very-High Temperature Reactor (VHTR)
– Sodium-Cooled Fast Reactors (SFR)
Very-High Temperature Reactor
• Reach temperatures > 1000 C
• Drive water splitting for hydrogen
production – 2 M m3
• 50% efficiency for producing electricity
• Heat and power generation
• Fuel recycling/reprocessing
• Fuel coating requirements, absorbers,
ceramic rods, vessel materials, passive
heat removal systems
Show pic
Actinide management
• To support effective actinide
management a fast reactor must have a
compact core with a minimum of
materials which absorb or moderate
fast neutrons. This places a significant
heat transfer requirement on the
coolant.
Sodium-Cooled Fast Reactors
• Old technology
• Management of waste
• Low system pressure, high thermal conductivity, large
safety margins.
• Burns almost all of the energy in uranium, as opposed to
1% in today’s plants
• Smaller core with higher power density, lower
enrichment, and lower heavy metal inventory.
• Primary system operates at just above atmospheric
pressure
• Secondary sodium circulation that heats the water (if it
leaks, no radiation release)
• Demonstrated capability for passive shutdown and
decay heat removal.
Show pic
Wind Energy
• Electricity
• In 2005, 18 GW produced in US, enough to
supply 1.6 million households
• By 2008, 121 GW worldwide (1.5 %)
• It has doubled in the last 3.5 years
• Largest farm in US in Texas
– 421 turbines, 230,000 homes
• Cape Cod/Long Island plan
• Capacity in US
– 170 turbines, 25 sq miles, 500,000 homes (2007)
– 28,635 MW, 1.5 M homes (as of April 30, 2009).
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Nation
2005
2006
2007
2008
9,149
11,603
16,819
25,170
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United States
2
Germany
18,428
20,622
22,247
23,903
3
Spain
10,028
11,630
15,145
16,740
4
China
1,266
2,599
5912
12,210
5
India
4,430
6,270
7850
9,587
6
Italy
1,718
2,123
2,726
3,736
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France
779
1,589
2,477
3,426
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United Kingdom
1,353
1,963
2,389
3,288
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Denmark
3,132
3,140
3,129
3,164
10
Portugal
1,022
1,716
2,130
2,862
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Canada
683
1,460
1,846
2,369
12
Netherlands
1,236
1,571
1,759
2,237
1,040
1,309
1,528
1,880
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20 % by 2030 initiative
• 300 GW goal
• The wind industry is on track to grow to a
size capable of installing 16,000 MW/year
Politics and economics
• Not in my backyard
• The cost of the project grows (the big dig
phenomenon
Cape cod
• 130 wind turbines
• 420 megawatts
• 3/4 of the Cape and Islands electricity
needs
• The late Senator Kennedy and the
candidates for his seat.
Long Island Wind Farm
• Each wind turbine will generate 3.6 megawatts.
• The project will consist of 40 turbines, producing
a total of 140 megawatts.
• The facility will generate enough energy to
power approximately 44,000 homes.
• Each turbine rotor has three blades
approximately 182 ft. long.
• The turbines shut down at wind speeds beyond
56 mph.
• Project called off in 2007 (voted down)
• But new project surfacing in 2008/09 700 (MWs)
Rhode Island
• State officials picked Deepwater Wind to
build a $1.5-billion, 385-megawatt wind
farm in federal waters off Block Island. The
100-turbine project could provide
1.3 terawatt-hours (TW·h) of electricity per
year - 15 percent of all electricity used in
the state.
2005 Report from the National
Renewable Energy Laboratory
• Estimates offshore US wind potential
• Offshore has several advantages over
onshore
– Land with greatest wind potentials are far
from populated centers
– Less of an eye sore
– Stronger, more dependable winds
– Use of larger, more economical turbines
GW by Depth (m)
Region
5-30
30-60
60-900
> 900
NE
10.3
43.5
130.6
0.0
Mid-atlantic
64.3
126.2
45.3
30.0
Great lakes
15.5
11.6
193.6
0.0
California
0.0
0.3
47.8
168.0
Pacific NW
0.0
1.6
100.4
68.2
90.1
183.2
517.7
266.2
Total
US Offshore Wind Resource Exclusions
Inside 5nm –100% exclusion􀂾
67% -5 to 20nm resource exclusion to account for avian, marine mammal,
view shed, restricted habitats, shipping routes & other habitats. 􀂾
33% exclusion–20 to 50 nm􀂾
Deep Water Wind Turbine Development
Deep water
• In June 2009, Secretary of the Interior Ken
Salazar issued five exploratory leases for
wind power production on the Outer
Continental Shelf offshore from New
Jersey and Delaware. The leases
authorize data gathering activities,
allowing for the construction of
meteorological towers on the Outer
Continental Shelf from six to 18 miles
offshore.
US Potential
• Over 1 TW, which is about equal to the total
capacity for electricity generation in US.
• Requires research into the construction of
off(off)shore turbines
• Research into potential environmental impacts
• Research into best sites (wind/wave action,
whale migration, ect.)
• 10-15 yrs from commercial deepwater
technology
Hydro
• 7 % of US electricity
• 70 % of renewable electricity
• Research:
– improving environmental impact of damming
– Expand use
– Hydrokinetic (wave, tidal, current, and ocean
thermal energy)
Potential of harnessing
wave energy
• Young technology
• But maybe 7 % of our total electricity
Fusion
• Rxn
• Nuclei confined by magnetic field
• Capture neutrons
– Extract heat
– Drive reaction (self-sustained)
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Steam-turbine-electricity
Physics of plasma
Materials
Stability
Research timeline
• JET – 16 MW for 0.5 s
– 1983-2004
• ITER – 500 MW for 1000 s
– 2018 start date
• DEMO – 2000 MW continuously
– 2030-2040
Carbon trapping
Energy use by sector (worldwide)
• Transportation 20 %
• Industrial 38 %
• Residential heating, lighting, and
appliances 11 %
• Commercial heating, lighting, sewer, ect,
5%
• 27 % lost in generation and transmission
Hydrogen Generation
• Uses Solar energy to generate hydrogen
• Photovoltaic cells convert light to electricity
that drives electrochemical splitting of
water to hydrogen and oxygen
• Earlier studies estimate the maximum
conversion efficiencies of 15 %
• Conversion efficiencies of 30 % have been
demonstated
30 % obtained by
• Eliminating the linkage of photo to
electrolysis surface area
• Ideal matching of photo- and electrolysis
potentials
• Incorporating better electrolysis catalysts
• Incorporating efficient multiple bandgap
photosensitizers
Hypothesis
• Further improvements can be made by using the
photons that are below the minimum band gap
energy of the sensitizers to heat the water.
• Theory predicts that the potential needed to
drive electrolysis decreases with increasing
temperature and lowers the overpotential.
• This would increase the efficiency of electrolysis
to about 40-50 %
Attempt to put the idea
into perspective
• How much energy could be produced from this
type of solar tower?
• From Figure 3, the potential power collected by
the photosensitizer is about 80 mW/cm2
• This equates to 80·108 W/km2
• Total Energy consumption (worldwide) is
1.5·1013 W
• Photosensitizers would have to take up an area
of 18800 km2 (100 % efficiency), 100000 km2
(18 %), 38000 km2 (50 %)
• 18%: PA, 50 %:Conn and MA
Figures
Electric Cars
• Plug in to charger in garage
• Limited mileage, but ideal for most
commuters
• Equivalent to over 150 mpg on a cost
basis
• Pb, NiCd, NiMH, Li ion, Li ion polymer
batteries (expensive to replace)
Toyota RAV4-EV
• Only 328 leased/purchased to individuals in
2003-04.
• Sold for $42000 in CA and Arizona (with Cal
rebate; $29,000
• Battery replacement $26000 (third party
vendors)
• About 80-120 miles (130-190 km) on full battery
• Top speed 78 miles/hr
• 0-60 in 18 s
• Charging takes 5 hrs
Debate: why have these electric
cars not been successful
• Cost?
• Performance?
• Conspiracy between oil companies and
auto industry
2007 electric cars
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Telsa Roadster
100 vehicles to be sold, 650 in 2008
Lithium ion batteries
0-60 in 4 s
135 mph equiv.
2 cents/mile
245 miles/charge
Top speed: 125 mph
$90,000
Company Strategy
Who killed the electric car?
• Chris Payne 2007 Documentary
• Consumers
– Lots of ambivalence to new technology, unwillingness to compromise on
decreased range and increased cost for improvements to air quality and
reduction of dependence on foreign oil.
• Batteries
– Limited range (60-70 miles) and reliability Lithium ion batteries, the
same technology available in laptops would have allowed the EV-1 to
be upgraded to a range of 300 miles per charge.
• Oil companies
– Fearful of losing business to a competing technology, they supported
efforts to kill the ZEV mandate. They also bought patents to prevent
modern batteries from being used in US electric cars.
• Car companies
– Negative marketing, sabotaging their own product program, failure to
produce cars to meet existing demand, unusual business practices with
regards to leasing versus sales.
Continued
• Government
– The federal government joined in the auto industry suit against
California, has failed to act in the public interest to limit pollution and
require increased fuel economy, has promoted the purchase of vehicles
with poor fuel efficiency through preferential tax breaks, and has
redirected alternative fuel research from electric towards hydrogen.
• California Air Resources Board
– The CARB, headed by Alan Lloyd, caved to industry pressure and
repealed the ZEV mandate. Lloyd was given the directorship of the new
fuel cell institute, creating an inherent conflict of interest.
• Hydrogen fuel cell
– The hydrogen fuel cell was presented by the film as an alternative that
distracts attention from the real and immediate potential of electric
vehicles to an unlikely future possibility embraced by automakers, oil
companies and a pro-business administration in order to buy time and
profits for the status quo.
GM is bring back the EV this coming year.
hybrid that also plugs into the wall.
It will be a
Li ion battery
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Battery specifications
Energy/weight160 Wh/kg
Energy/size270 Wh/L
Power/weight1800 W/kg
Charge/discharge efficiency99.9%[1]
Energy/consumer-price2.8-5 Wh/US$[2]
Self-discharge rate5%-10%/month
Time durability(24-36) months
Cycle durability1200 cycles
Nominal Cell Voltage3.6 / 3.7 V
electrochemistry
• In a lithium-ion battery the lithium ions are
transported to and from the cathode or
anode, with the transition metal, Co, in
LixCoO2 being oxidized from Co3+ to Co4+
during charging, and reduced from Co4+ to
Co3+ during discharge.
Recent Advances
• Nano-sized titanate electrode material for lithium-ion batteries. I
• three times the power output of existing batteries and can be fully
charged in six minutes.
• 20,000 recharging cycles, so durability and battery life are much
longer, estimated to be around 20 years
• The batteries can operate from -50 °C to over 75 °C and will not
explode or result in thermal runaway even under severe conditions
because they do not contain graphite-coated-metal anode electrode
material
• The batteries are currently being tested in a new production car
made by Phoenix Motorcars which was on display at the 2006
SEMA motorshow.
• In March 2005, Toshiba announced another fast charging lithium-ion
battery, based on new nano-material technology, that provides even
faster charge times, greater capacity, and a longer life cycle. The
battery may be used in commercial products in 2006 or early 2007,
primarily in the industrial and automotive sectors.