Transcript Options

Options
Energy Future: Options
(An SE’s Sample Of Topics)
• Options for sources
– “Reduced Carbon” fossil fuel
– Renewables
– Nuclear
• Options for energy transport systems
– Hydrogen
• Options for efficiencies
– Distributed generation
– Spinning reserve
• Options for policies
Energy Future: Options
Energy Future: Options
• Options for sources
– “Reduced Carbon” fossil fuel
– Renewables
– Nuclear
• Options for energy transport systems
– Hydrogen
• Options for efficiencies
– Distributed generation
– Spinning reserve
• Options for policies
Energy Future - 20040116
• Topics:
– The importance of
Natural Gas
– A solar future
– Nuclear?
Carbon Intensity of Energy Mix
M. I. Hoffert et. al., Nature, 1998, 395, 881
Source: Nathan Lewis
LNG
• Worldwide proven reserves of Natural
Gas: 5500 T ft3
– 1999 – 84 T ft3 total, worldwide production
• U.S. production of liquefied natural gas
(LNG) has plateaued.
• New U.S. electric power plants are largely
natural gas
• Prediction: by 2020, 25% of the world’s
energy will be natural gas
Arabicnews.com, 12/19/2003
•Source:
Consumption:
LNG
http://www.kryopak.com/LNGships.html
LNG requires a heavy infrastructure for
cooling and transportation.
This is currently capacity limited.
http://www.energy.ca.gov/lng/
Coal Gasification And
Sequestering
• Great Plains Coal Gasification Plant (North
Dakota)
• From coal to the equivalent of natural gas
• Sequester carbon dioxide into oil fields to
assist in pumping
– Oil field operator pays for Carbon Dioxide
http://www.dakotagas.com/
Renewable Energy Potential
Source
Biomass
Technical Potential
6-15 TW
Wind
2-6 TW
Solar
45-1500 TW
Hydro
1 TW
Marine
Nil
Geothermal
150 TW
Recall that the world needs 20 TW of carbon-free energy by 2050.
Source: Turkenburg, Utrecht University
Solar Energy Potential
• Facts:
– Theoretical: 1.2x105 TW solar energy
potential (1.76 x105 TW striking Earth; 0.30
Global mean albedo)
– Practical: ≈ 600 TW solar energy potential
• 50 TW - 1500 TW depending on land fraction etc.;
WEA 2000
• Onshore electricity generation potential of ≈ 60
TW (10% conversion efficiency):
– Photosynthesis:
90 TW
Source: Nathan Lewis
Solar Thermal Energy Potential
• Roughly equal global energy use in each major
sector:
–
–
–
–
transportation
residential
transformation
industrial
• World market: 1.6 TW space heating; 0.3 TW hot
water; 1.3 TW process heat (solar crop drying: ≈
0.05 TW)
• Temporal mismatch between source and
demand requires storage
– (DS)
Source:yields
Nathanhigh
Lewisheat production costs: ($0.03$0.20)/kW-hr
– High-T solar thermal: currently lowest cost solar
PV Land Area Requirements
For U. S. Energy Independence
• Facts:
– U.S. Land Area: 9.1x1012 m2 (incl. Alaska)
– Average Insolation: 200 W/m2
– 2000 U.S. Primary Power Consumption: 99
Quads= 3.3 TW
– 1999 U.S. Electricity Consumption = 0.4 TW
• Conclusions:
– 3.3 TW /(2x102 W/m2 x 10% Efficiency) =
11 m2
1.6x10
Source: Nathan Lewis
– Requires 1.6x1011 m2/ 9.1x1012 m2 = 1.7% of
PV Land Area Requirements
3 TW
20 TW
Source: Nathan Lewis
It takes .16% of the Earth’s surface
to generate the Carbon Free
energy needed in 2050
• 1.2x105 TW of solar energy potential
globally
• Generating 20 TW with 10% efficient solar
farms requires: 2x102/1.2x105 = 0.16% of
Globe = 8x1011 m2 (i.e., 8.8 % of U.S.A)
• Generating 1.2x101 TW (1998 Global
Primary Power) requires: 1.2x102/1.2x105=
11 m2 (i.e., 5.5% of
0.10%
of
Globe
=
5x10
Source: Nathan Lewis
U.S.A.)
A “Notional” Distribution Of PV
“Farms” To Achieve 20 TW of
Carbon Free Energy in 2050
6 Boxes at 3.3 TW Each
Source: Nathan Lewis
How Much Energy Can Be
Produced On The Roofs of
Houses?
7
• 7x10 detached single family homes in
U.S.
– ≈2000 sq ft/roof = 44ft x 44 ft = 13 m x 13 m =
180 m2/home or … 1.2x1010 m2 total roof area
• This can (only) supply 0.25 TW, or ≈1/10th
of 2000 U.S. Primary Energy Consumption
• … but this could provide local space
Source: Nathan
Lewis(daytime) capacity.
heating,
surge
Efficiency of Photovoltaic
Devices
25
Efficiency (%)
20
15
10
crystalline Si
amorphous Si
nano TiO2
CIS/CIGS
CdTe
5
1950
1960
1980
1970
1990
2000
Year
Source: Nathan Lewis
Margolis and Kammen, Science 285, 690 (1999)
Status Of Solar Photovoltaics
• Current efficiencies of PV modules:
– 6-9% on amorphous Silicon; 13-19% for crystaline
Silicon
– Performance efficiency improvement of 2X is
anticipated
• Increase in PV shipments (50MW in 1991; 280
MW in 2000)
• Continuous reduction in investment costs up
front
– Rate of decline is 20%/year
– Current cost is $5/Watt; target is $1/Watt (5X)
• Payback time will be reduced from 3-9 years to 1-2 years
Source: Turkenburg, Utrecht University
Nuclear As An Option?
• Nuclear plants do not scale well.
– Typically most effective at 1 GWatt
• To produce 10 TW of power …
– 10000 new plants over the next 50 years
– One every other day, somewhere in the world
• Nuclear remains an option
• Fusion power remains as a “great hope”
Energy Future: Options
Energy Future: Options
• Options for sources
– “Reduced Carbon” fossil fuel
– Renewables
– Nuclear
• Options for energy transport systems
– Hydrogen
• Options for efficiencies
– Distributed generation
– Spinning reserve
• Options for policies
Energy Future - 20040116
• Topics:
– Hydrogen
– Fuel Cells
Hydrogen
• Widely produced in today’s world economy
– Steam-methane reformer (SMR) process
– Just now, beginning to successfully scale
down (e.g. to be used at “gas stations” in
future (100,000 places in U.S,).
Source: NAE Article, The Bridge, “Microgeneration Technology”, 2003
Electrolysis
• Hydrogen can also be made from solar
power on electrolysis of water
– A liquid, transportable form can be produced
(methanol; (good catalysts exist to do this
from CO2 )). This ends up as carbon neutral or
CO.
• At bulk power costs of $.03/W electrolysis
of water can compete with compressed or
liquid H2 (transported)
– Could produce small quantities of H2 to fuel
cars, even at the level of a residence
Hydrogen, Again
• Fuel cells using Proton Exchange
Membrane have made enormous
progress, but are still expensive.
• Hydrogen storage in carbon fiber
strengthened aluminum tanks.
– Hydride systems and carbon from solar power
on electrolysis of water
• A liquid, transportable form can be produced
(methanol; (good catalysts exist to do this from
CO2). This ends up as carbon neutral.
• Hydrides appear to be promising as means of
storing hydrogen gas
Is there Carbon in Hydrogen?
• If used in a fuel cell, Hydrogen still
produces Carbon (Dioxide) because of
how it was manufactured:
– 145 grams/mile if it comes from natural gas
– 436 grams/mile if it comes from grid electricity
• But, for context:
– 374 grams/mile if it came from gasoline (no
fuel cell)
– 370 grams/mile if natural gas had been used
directly (no fuel cell).
Source: Wald, New York Times, 11/12/2003
Fuel Cell Technology
Proton
Alkaline
Exchang
e
Membran
e
Solid
Oxide
Molten
Carbonat
e
Phosphor
ic Acid
Operating 80
temperatur
e (oC)
80
1000
650
200
Power
Density
(watts/kg.)
340-1500
35-105
15-20
30-40
120-180
Efficiency
(%)
40-60
40-60
45-50
50-57
40-47
Time to
Operation
Seconds
Minutes
Hours (10)
Hours (10)
Hours (2)
Platinum
Used
Yes
No
No
No
No
Issues
Cost,
Time,
Time,
Time,
Time, temp,
Source: CETC
Fuel Cell Power Generation Is
Emerging
Source: Ballard
Energy Future: Options
Energy Future: Options
• Options for sources
– “Reduced Carbon” fossil fuel
– Renewables
– Nuclear
• Options for energy transport systems
– Hydrogen
• Options for efficiencies
– Distributed generation
– Spinning reserve
• Options for policies
Energy Future - 20040116
• Topics:
– Distributed Power
Generation
– Spinning capacity
Microgeneration Technology
(Distributed Generation)
• 7% of the world’s energy is generated on a
distributed basis
– In some countries this is up to 50%
• Generate power close to the load
– 10 – 1000 kW (traditional power plants are 100 –
1000 MW)
• Internal Combustion, Turbine, Stirling Cycle (with efficiencies
approaching 40%), Solid-oxide fuel cells (over 40%
efficiency), Wind Turbines, PV
– Modular (support incremental additions of capacity)
– Low(er) capital cost
– Waste heat can be captured and used locally via
Source: NAE Article,
The Bridge, “Microgeneration
Technology”,
2003
Combined
Heat and
Power
(CHP) systems
Spinning Reserves From
Responsive Loads
• How to avoid significant “reserves” in
power generation?
• Control both generation and load:
– Historically only generation was controlled
– Network technology enables control of load
(through management of numerous small
resources)
Source: Oak Ridge Research Report, March 2003.
Spinning Reserve From
Responsive Loads
(Smart Energy)
Carrier ComfortChoice themostats
provide significant monitoring capability
- Hourly data
- No. of minutes of compressor/heater operation
- No. of starts
- Average temperature
- Hour end temperature trend
- Event data
- Accurate signal receipt and control action time
stamp
Conservation
•
•
•
•
Hybrid Vehicles
Space heating
Water heating
Co-generation
Energy Future: Options
(Policies)
Energy Future: Options
• Options for sources
– “Reduced Carbon” fossil fuel
– Renewables
– Nuclear
• Options for energy transport systems
– Hydrogen
• Options for efficiencies
– Distributed generation
– Spinning reserve
• Options for policies
Energy Future - 20040116
• Topics:
– Taxes
– Forced Standards
– Research and
Development
Energy Future: The EE Role
• Electricity is the future
– Most energy sources will come via electricity
• Systems will have to be significantly more
efficient, smarter:
–
–
–
–
–
–
More distribution
More connectivity (communication)
More intelligence
More information
More integration
More
transparency
Electrical
Engineers will play a critical role
in making
transition effective
• The entire
energythis
infrastructure
will have to be
changed within 50-100 years
Conclusions
Conclusions (Mine)
• There is an “energy problem” (a “carbon problem”), an
unsustainable dependence on fossil fuel
• Market forces and innovation will play a major role, but are
not responsive enough to deal with mass scale, current
low costs of energy, and long time constants
– The economic impact of a forced shift from fossil fuels is
unacceptable
– Policy shifts and long term investment are needed
• Natural Gas to Solar is the most visible path to
sustainability, today
– Major, near term investment in Natural Gas infrastructure is
needed
– Cost of a major solar power infrastructure is daunting, but we
should organize ourselves for this eventuality
• Hydrogen can/will become an important transport system
(start with methane derived hydrogen and move toward
renewable resource driven hydrogen)
Questions and Comments