Renewable Energy Overview

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					                                                        A. Shakouri 3/25/2009




Overview of Renewable
   Energy Sources
              Ali Shakouri
      Baskin School of Engineering
    University of California Santa Cruz
            http://quantum.soe.ucsc.edu/




       Philips Research Lab, Eindhoven, Netherlands; 25 March 2009
                                                                 1
World Marketed Energy Use by                                           A. Shakouri 3/25/2009


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)
                                                                                          2
US Energy Consumption                             A. Shakouri 3/25/2009




   DOE Energy Information Administration (2007)
                                                                     3
                     A. Shakouri 3/25/2009




Martin Green, UNSW
                                        4
                     Cost of Renewable Energy                                                                                                                                   A. Shakouri 3/25/2009




                            Levelized cents/kWh in constant $2000

                                                   40                                                        100
                                                                                    Wind                                                                           PV




                                                                                                     COE cents/kWh
                                   COE cents/kWh



                                                                                                                     80
                                                   30
                                                                                                                     60
                                                   20
                                                                                                                     40
                                                   10
                                                                                                                     20
                                                   0                                                                 0
                                                   1980   1990   2000             2010     2020                      1980    1990                   2000    2010    2020


                10                                         70                                                                                       15
                                             Geothermal    60                                     Solar thermal                                                                Biomass




                                                                                                                                    COE cents/kWh
COE cents/kWh




                                                                  COE cents/kWh




                8                                                                                                                                   12
                                                           50
                6                                          40                                                                                        9
                                                           30                                                                                        6
                4
                                                           20
                2                                          10                                                                                        3
                0                                           0                                                                                        0
                1980      1990             2000  2010 2020 1980                          1990     2000                2010   2020                    1980    1990       2000     2010        2020


                       Source: NREL Energy Analysis Office
                       These graphs are reflections of historical cost trends NOT precise annual historical data.                               Keith Wipke, NREL
                       Updated: October 2002
                                                                                                                                                                                                   5
Microprocessor Evolution                             A. Shakouri 3/25/2009




                   K         1 Billion
       1,000,000           Transistors
        100,000
                                      Pentium® 4
                                     Pentium® III
         10,000                    Pentium® II
          1,000                   Pentium®
                               i486
                            i386
            100          80286
                       8086
             10

               1
               ’75 ’80 ’85 ’90 ’95 ’00 ’05 ’10 ’15




                                                                        6
Airplane Speed/Efficiency Evolution                              A. Shakouri 3/25/2009




             Airplane Speed                  US Energy Intensity (MJ)
                                              per available seat km
                                               @ 160kg payload/seat




McMasters & Cummings, Journal of   NLR-CR-2005-669;Peeters P.M., Middel
Aircraft, Jan-Feb 2002             J., Hoolhorst A.

                                                                                    7
                                                   A. Shakouri 3/25/2009




Felix’s
forecasts of
                        Nuclear
US energy
consumption
in year 2000     Natural
                 gas
(early 1970’s)
                  Oil

                   Coal           Vaclav Smil,
                                  Energy at the Crossroads,
                                  2005
                                                                      8
       Electric Potential of Wind                     A. Shakouri 3/25/2009




• 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 earth’s land is
   class >3 => 50 TW
   Practical: 2 TW potential (4% utilization)

   Off-shore potential is larger but must be close
   to grid to be interesting; (no installation > 20
   km offshore now)
                          Nate Lewis, Caltech                            9
     Turbine Sizes                            A. Shakouri 3/25/2009




Trend toward bigger turbine sizes
                       Helge Aagaard Madsen, DTU Riso10
                              A. Shakouri 3/25/2009




http://www.eere.energy.gov/                    11
Offshore Wind Farm                       A. Shakouri 3/25/2009
                                        A. Shakouri 11/25/2008


          Nysted, Denmark




EE 181 Renewable Energies in Practice
    CA-Denmark Summer Program
              2008                                        12
       Geothermal Energy Potential                            A. Shakouri 3/25/2009




• Mean terrestrial geothermal flux at earth’s 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                                 13
Energy from the Oceans?                       A. Shakouri 3/25/2009




    Currents                 Thermal Differences




     Tides                          Waves
               Ken Pedrotti, UCSC                              14
       Biomass Energy Potential                      A. Shakouri 3/25/2009




                     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                         15
                                         A. Shakouri 3/25/2009




                          Amount of land
                          needed for 20 TW at
                          1% efficiency:
                          9% of land



Chris Somerville, UC Berkeley                             16
Corn Ethanol Greenhouse Gas Emission                A. Shakouri 3/25/2009




               Farrell et al. (Science 311, 2006)                    17
           A. Shakouri 3/25/2009




Steve Koonin, BP            18
Biofuels                 A. Shakouri 3/25/2009




           Dan Kammen, Berkeley           19
                                                                        A. Shakouri 3/25/2009




Bioenergy and Sustainable Development, Ambuj D. Sagar, Sivan Kartha
Annual Review of Environment and Resources, Vol. 32: 131-167 (November 2007)             20
            Solar Energy Potential                          A. Shakouri 3/25/2009




• 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                               21
          World Insolation   A. Shakouri 3/25/2009




                   12 TW
2.0-2.9

4.0-4.9

6.0-6.9




                                              22
      A. Shakouri 3/25/2009




         Boyle
    Renewable
Energy Sources



                       23
Potential of Carbon Free Energy Sources
                                                                                       A. Shakouri 3/25/2009
                                                                                      A. Shakouri 11/25/2008




From: Basic Research Needs for Solar Energy Utilization, DOE 2005
                                                                Chris Somerville, UC Berkeley           24
     A. Shakouri 3/25/2009




 Vaclav Smil
Energy at the
 Crossroads
                      25
Specific Power (W/kg)   Energy Storage Options                A. Shakouri 3/25/2009




                                                 Combustion
                                                 Engine




                                 Specific Energy (Wh/kg)
                                                                               26
                          Power ~3.3TW
                                                       A. Shakouri 11/25/2008
                                                        A. Shakouri 3/25/2009




1.3TW                                    Rejected
                                        Energy 61%




        Lawrence Livermore National Lab., http://eed.llnl.gov/flow
                                                                 27
          India’s Energy Consumption 2005
                                            A. Shakouri 3/25/2009




                                             Waste
                                             Energy

Biomass




Coal




Petroleum


                                                             28
Direct Conversion of Heat into Electricity                       A. Shakouri 3/25/2009




Seebeck coefficient    DV                    Hot                 Cold
                    S
     (1821)            DT                          Electrical
                                                   Conductor


                                                   DV~ S DT                I
Efficiency function of
thermoelectric figure-of-merit (Z)

   S 2
Z                                            Rload = RTE internal
    k
   ( Seebeck ) 2 (electrical conductivity)
Z
          (thermal conductivity)


                                                                                  29
 Power Generation Efficiencies of
 Different Technologies                                                                             A. Shakouri 3/25/2009




                                      0.8
                                              ZTm=0.5
              Conversion Efficiency   0.7
                                              ZTm=1
                                              ZTm=2
                                              ZTm=3Carnot
                                              Carnot limit
                                      0.6                                                    ZTavg=20
       Energy Optimal efficiency


                                                                    Coal/ Rankine
                                      0.5

                                      0.4         Solar/ Stirling

                                                             Solar/ Rankine
                                                                                            3
                                      0.3
                                                                                            2
                                             Cement/ Org.
                                      0.2    Rankine                                        1
                                      0.1                                                   0.5

                                       0
                                            400     600          800      1000      1200
  Geothermal/
Organic Rankine                                                T (K)
                                                                 hot                       C. Vining 2008
                                                                                                                     30
Radioisotope Thermoelectric Generators                            A. Shakouri 3/25/2009


     (Voyager, Galileo, Cassini, …)
• 55 kg, 300 We, ‘only’ 7 % conversion efficiency
• But > 1,000,000,000,000 device hours without a single
  failure
                                               Hot Shoe (Mo-Si)



                                       B-doped              P-doped
                                       Si0.78Ge0.22         Si0.78Ge0.22

                                       B-doped              P-doped
                                       Si0.63Ge0.36         Si0.63Ge0.36

                                       p-type leg           n-type leg
                                                         Cold Shoe


                                               SiGe unicouple
                  Cronin Vining, ZT Services                                       31
Which Materials To Choose for TE Modules?
                                                                                   A. Shakouri 3/25/2009




               Seebeck                                           Electrical
                                 S                              Conductivity
                                           S2
ZT=
S2T/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  ↔ k                                  32
         Microrefrigerators on a chip                                                         A. Shakouri 3/25/2009


• Monolithic integration on silicon                     UCSC, UCSB, HRL Labs
• DTmax~4C at room temp. (7C at 100C)
         Hot               Cold
       Electron           Electron




                                                                                                  Relative
                                                                                                 Temp. (C)


                                                                           50mm
                         1 µm
                                                           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                             33
            Hot Electron Filters in
    Metal/Semiconductor Nanocomposites                                                      A. Shakouri 3/25/2009



    Even with only modestly low lattice thermal conductivity and
 electron mobility of typical metals, ZT > 5 is theoretically possible
                       Assume: klattice=1W/mK, mobility ~10 cm2/Vs
                        8                                            5

                        7         Metal/Semiconductor
                                                                     4
                                     Nanostructure
                                      Non-conserved
                        6




                                                                               (E
 D. Vashaee,                                                         3




                                                                          barrier
                        5
 A. Shakouri;
                  ZT




                                                                               -E ) / k T
Physical Review         4                                            2




                                                                          f
 Letters, 2004
                        3                  • Need lattice-compatible
                                                                   1
                                             composites with appropriate




                                                                          B
                        2
                                             barrier heights       0
                        1                  Planar Barrier
                                               Conserved
                        0                                            -1
                            0     2    4      6    8   10   12     14
                                FermiFermi Energy (eV)
                                      energy eV (↔ free electron
                                         concentration)
                                                                                                             34
         ErAs Semi-metal Nanoparticles
    imbedded in InGaAs Semiconductor Matrix                                A. Shakouri 3/25/2009




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


                                           As In,Ga
                                                           Er
                                            1nm



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




                                                     J. Zide et al. UCSB/UCSC               35
          Beating the Alloy Limit in Thermal Conductivity
                                             ErAs:In0.53Ga0.47As                           A. Shakouri 3/25/2009


       Phonon scattering by ErAs nanoparticles
            3-fold reduction in thermal conductivity beyond the alloy limit
Thermal Conductivity [W/m-K]




                                                 InGaAs
                               6



                                       0.3% ErAs:InGaAs

                               3
                                        3% ErAs:InGaAs                                Nanoparticle

                                         6% ErAs:InGaAs


                               0
                                   0      200         400          600          800
                                                Temperature [K]      W. Kim et al. UCB/UCSB/UCSC            36
                                  Module Power generation results                            A. Shakouri 3/25/2009



                       400 elements (10-20 microns ErAs:InGaAlAs thin films,
                       120x120mm2)
                         3
Output Power (W/cm )




                                        20 mm module
2




                        2.5
                                        10 mm module
                         2

                        1.5

                         1

                        0.5

                         0
                              0    20   40   60   80   100   120   140
                                                                         G. Zeng, J. Bowers, et al.
                                             DT (K)                      (UCSB, UCSC) Appl. Physics
                                        140 mm/140 mm AlN                Letters 2006               37
                      Summary                           A. Shakouri 3/25/2009




• 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 > 500 W/cm2
• Metal semiconductor nanocomposites for direct
  conversion of heat into electricity
  • Potential to reach 20-30% conversion efficiencies


                                                                         38
                       A. Shakouri 3/25/2009
                      A. Shakouri 11/25/2008




Nate Lewis, Caltech                     39
               Plan B for Energy                   A. Shakouri 3/25/2009




   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

                                                                    40
A. Shakouri 3/25/2009




                 41
Can Renewables Save the World?                         A. Shakouri 3/25/2009



• 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.).
                                                                        42
                         A. Shakouri 3/25/2009




World Average




     John Bowers, UCSB                    43
Can Renewables Save the World?                   A. Shakouri 3/25/2009



• 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).




                                                                  44
Oil Resources           A. Shakouri 3/25/2009



 S. Koonin, Chief Scientist BP
       nrg.caltech.edu




                                         45
                        A. Shakouri 3/25/2009


400,000 years of
greenhouse-gas &
temperature
history based on
bubbles trapped
in Antarctic ice



Last time CO2 >300
ppm was 25 million
years ago.


  Source: Hansen,
  Clim. Change, 68,
  269, 2005.

John P. Holdren, 2006
                                         46
EE80J Renewable Energy Sources
Spring 2009, Also Summer 2009             A. Shakouri 3/25/2009




•   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                          47

				
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