Overview of Renewable Energy Sources Ali Shakouri Baskin

1
Overview of Renewable Energy Sources
Ali Shakouri Baskin School of Engineering Universi
ty of California Santa Cruz http//quantum.soe.ucs
c.edu/
Philips Research Lab, Eindhoven, Netherlands 25
March 2009
2
World Marketed Energy Use by Fuel Type 1980-2030
2050 25-30TW
13TW
34
28
38
24
26
Share of World Total
23
8
7
6
6
US Department of Energy Energy Information
Administration (2007)
3
US Energy Consumption
DOE Energy Information Administration (2007)
4
Martin Green, UNSW
5
Cost of Renewable Energy
Levelized cents/kWh in constant 2000
4030 20 10 0
Wind
COE cents/kWh
1980 1990 2000 2010 2020
Source NREL Energy Analysis Office These graphs
are reflections of historical cost trends NOT
precise annual historical data. Updated October
2002
Keith Wipke, NREL
6
Microprocessor Evolution
7
Airplane Speed/Efficiency Evolution
US Energy Intensity (MJ) per available seat km
_at_ 160kg payload/seat
Airplane Speed
McMasters Cummings, Journal of Aircraft,
Jan-Feb 2002
NLR-CR-2005-669Peeters P.M., Middel J.,
Hoolhorst A.
8
Felixs forecasts of US energy consumption in
year 2000 (early 1970s)
Nuclear
Natural gas
Oil
Coal
Vaclav Smil, Energy at the Crossroads, 2005
9
Electric Potential of Wind

• Significant potential in US Great Plains, inner
  Mongolia and northwest China
• U.S.
• Use 6 of land suitable for wind energy
  development practical electrical generation
  potential of 0.5 TW
• Globally
• Theoretical 27 of earths land is
  class gt3 gt 50 TW
• Practical 2 TW potential (4 utilization)
• Off-shore potential is larger but must be close
  to grid to be interesting (no installation gt 20
  km offshore now)

Nate Lewis, Caltech
10
Turbine Sizes
Trend toward bigger turbine sizes
Helge Aagaard Madsen, DTU Riso
11
http//www.eere.energy.gov/
12
Offshore Wind Farm
A. Shakouri 11/25/2008

• Nysted, Denmark

EE 181 Renewable Energies in Practice CA-Denmark
Summer Program 2008
13
Geothermal Energy Potential

• Mean terrestrial geothermal flux at earths
  surface 0.057 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)

Nate Lewis, Caltech
14
Energy from the Oceans?
Thermal Differences
Currents
Waves
Tides
Ken Pedrotti, UCSC
15
Biomass Energy Potential

• Global Top Down
• Requires Large Areas Because Inefficient (0.3)
• 3 TW requires 600 million hectares 6x1012
  m2
• 20 TW requires 4x1013 m2
• Total land area of earth 1.3x1014 m2
• Hence requires 4/13 31 of total land area

Nate Lewis, Caltech
16
Amount of land needed for 20 TW at 1
efficiency 9 of land
Chris Somerville, UC Berkeley
17
Corn Ethanol Greenhouse Gas Emission
Farrell et al. (Science 311, 2006)
18
Steve Koonin, BP
19
Biofuels
Dan Kammen, Berkeley
20
Bioenergy and Sustainable Development, Ambuj D.
Sagar, Sivan Kartha Annual Review of Environment
and Resources, Vol. 32 131-167 (November 2007)
21
Solar Energy Potential

• Theoretical 1.2x105 TW solar energy potential
• Practical 600 TW solar energy potential
• Onshore electricity generation potential of 60
  TW (10 conversion efficiency)
• Photosynthesis 90 TW
• Generating 12 TW (1998 Global Primary Power)
  requires 0.1 of Globe 5x1011 m2 (i.e.,
  5.5 of U.S.A.)

Nate Lewis, Caltech
22
World Insolation
12 TW
2.0-2.9
4.0-4.9
6.0-6.9
23
Boyle Renewable Energy Sources
24
Potential of Carbon Free Energy Sources
A. Shakouri 11/25/2008
From Basic Research Needs for Solar Energy
Utilization, DOE 2005
Chris Somerville, UC Berkeley
25
Vaclav Smil Energy at the Crossroads
26
Energy Storage Options
Combustion Engine
Specific Power (W/kg)
Specific Energy (Wh/kg)
27
Power 3.3TW
A. Shakouri 11/25/2008
Rejected Energy 61
1.3TW
Lawrence Livermore National Lab.,
http//eed.llnl.gov/flow
28
Indias Energy Consumption 2005
Waste Energy
Biomass
Coal
Petroleum
29
Direct Conversion of Heat into Electricity
Seebeck coefficient (1821)
Hot
Cold
Electrical Conductor
DV S DT
Efficiency function of thermoelectric
figure-of-merit (Z)
30
Power Generation Efficiencies of Different
Technologies
Carnot
ZTavg20
Coal/ Rankine
Energy Conversion Efficiency
Solar/ Stirling
3
Solar/ Rankine
2
Cement/ Org. Rankine
1
0.5
Geothermal/ Organic Rankine
C. Vining 2008
31
Radioisotope Thermoelectric Generators
(Voyager, Galileo, Cassini, )

• 55 kg, 300 We, only 7 conversion efficiency
• But gt 1,000,000,000,000 device hours without a
  single failure

Cronin Vining, ZT Services
32
Which Materials To Choose for TE Modules?
Electrical Conductivity
Seebeck
s
S
S2s
ZT S2sT/k
Free carrier concentration
Thermal Conductivity
Electronic contribution
k
Lattice contribution
Insulator Semiconductor Metal
For almost all materials, if doping is increased,
electrical conductivity increases but Seebeck
coefficient is reduced. Similarly s ? k
33
Microrefrigerators on a chip

• Monolithic integration on silicon
• DTmax4C at room temp. (7C at 100C)

J. Christofferson
Nanoscale heat transport and microrefrigerators
on a chip A. Shakouri, Proceedings of IEEE, July
2006
Featured in Nature Science Update, Physics Today,
AIP April 2001
34
Hot Electron Filters in Metal/Semiconductor
Nanocomposites
Even with only modestly low lattice thermal
conductivity and electron mobility of typical
metals, ZT gt 5 is theoretically possible
Assume klattice1W/mK, mobility 10 cm2/Vs
Metal/Semiconductor Nanostructure
D. Vashaee, A. Shakouri Physical
Review Letters, 2004

• Need lattice-compatible composites with
  appropriate barrier heights

Fermi energy eV (? free electron concentration)
35
ErAs Semi-metal Nanoparticles imbedded in InGaAs
Semiconductor Matrix

• ErAs dots are lattice-matched and incorporate
  without any visible defects in InGaAs despite
  different crystal structures (Cubic vs.
  Zinc-blende)

• Random ErAs particles 2-3 nm
• Size is invariant to growth conditions

J. Zide et al. UCSB/UCSC
36
Beating the Alloy Limit in Thermal Conductivity
ErAsIn0.53Ga0.47As
Phonon scattering by ErAs nanoparticles ? 3-fold
reduction in thermal conductivity beyond the
alloy limit
W. Kim et al. UCB/UCSB/UCSC
37
Module Power generation results
400 elements (10-20 microns ErAsInGaAlAs thin
films, 120x120mm2)
G. Zeng, J. Bowers, et al. (UCSB, UCSC) Appl.
Physics Letters 2006
140 mm/140 mm AlN
38
Summary

• Significant amount of energy produced in the
  world is wasted in the form of heat (61 is US)
• Thermoelectric effects can be engineered via
  nanomaterials
• Modify the average energy of moving electrons
• Selective scattering of phonons w.r.t electrons
• Micro refrigerators on a chip (silicon based)
• Localized cooling, Cooling power density gt 500
  W/cm2
• Metal semiconductor nanocomposites for direct
  conversion of heat into electricity
• Potential to reach 20-30 conversion efficiencies

39
A. Shakouri 11/25/2008
Nate Lewis, Caltech
40

• Plan B for Energy
• September 2006 Scientific American W. Wayt
  Gibbs
• WAVES AND TIDES (Reality factor 5)
• HIGH-ALTITUDE WIND (Reality factor 4)
• NANOTECH SOLAR CELLS (Reality factor 4)
• DESIGNER MICROBES (Reality factor 4)
• NUCLEAR FUSION (Reality factor 3)
• SPACE-BASED SOLAR (Reality factor 3)
• A GLOBAL SUPERGRID (Reality factor 2)
• SCI-FI SOLUTIONS (Reality factor 1)
• Cold Fusion and Bubble Fusion
• Matter-Antimatter Reactors

41
(No Transcript)
42
Can Renewables Save the World?

• Fossil fuels have excellent energy
  characteristics.
• Wind/ geothermal are among the cheapest of
  renewables. There is potential for significant
  growth but they can not solve our energy problem.
• Solar energy has the potential to provide all our
  energy needs.
• Currently expensive it is intermittent.
• Currently no clear options for large scale energy
  storage
• Biomass has the potential to provide part of
  transportation energy needs
• Cellulosic biofuels and algaes are interesting
  but they have not demonstrated large scale/long
  term potential. One has to consider the full
  ecosystem impact (water, food, etc.).

43
World Average
John Bowers, UCSB
44
Can Renewables Save the World?

• If our goal is to have a planet where everybody
  has a level of life similar to developed
  countries, energy need is enormous and it is not
  clear if we can do this by working on the supply
  side alone.
• Energy efficiency is important but it is not
  enough.
• We need to consider changes in lifestyle, city
  planning and social structure (transportation,
  lodging, grid).

45
Oil Resources
S. Koonin, Chief Scientist BP nrg.caltech.edu
46
400,000 years of greenhouse-gas temperature
history based on bubbles trapped in Antarctic ice
Last time CO2 gt300 ppm was 25 million years
ago.
Source Hansen, Clim. Change, 68, 269, 2005.
John P. Holdren, 2006
47
EE80J Renewable Energy SourcesSpring 2009, Also
Summer 2009

• Energy, power and thermodynamics
• Home energy audit
• Power plants, nuclear power
• Solar energy
• Wind energy, hydropower, geothermal
• Biomass, hydrogen, fuel cells
• Economics, Environmental and Societal Impacts

EE181J Renewable Energies in Practice
(July-August 2009)
CA/Denmark summer school (UCSC, UC Davis, UC
Merced, Techn. Univ. Denmark, Roskilde)
Extensive field trips
UCSC Courses