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					    W. Bill Booth                                                                       Bruce A. Measure
       Chair                                                                               Vice-Chair
       Idaho                                                                                Montana

    James A. Yost                                                                        Rhonda Whiting
       Idaho                                                                                Montana

     Tom Karier                                                                          Melinda S. Eden
     Washington                                                                              Oregon

    Dick Wallace                                                                          Joan M. Dukes
    Washington                                                                               Oregon



                                           February 26, 2009

MEMORANDUM
TO:                 Power Committee

FROM:               Jeff King, Senior Resource Analyst

SUBJECT:            Assessment of geothermal generating resource potential

Aggressive renewable portfolio standards and greenhouse gas control policies have increased the
demand for sources of renewable or low-carbon energy. Geothermal energy, the crustal heat of
the earth, is one such source. Conventional (hydrothermal) geothermal power generation relies
on naturally-present water in near-surface porous heated rock as the heat transfer mechanism.
The water is brought to the surface by means of wells and used directly or indirectly to drive a
turbine-generator. The cooled geothermal fluid is then recycled to the underlying rock
formation.

Geologic structures found in the Northwest thought to have potential for conventional
geothermal electricity generation include the Basin and Range area of southeastern Oregon and
southern Idaho, magma bodies underlying volcanic structures in the Cascade Range and certain
locations in the Snake River Plain. Developable sites possessing the water, rock, and
temperature qualities required for geothermal generation are rare, and geothermal exploration
and development are expensive and financially risky ventures.

The 13 megawatt (net) Raft River project in southeastern Idaho, commissioned in January 2008,
is the first commercial geothermal power plant in the Northwest. An expansion of Raft River is
planned for 2009. Several additional Northwest projects have been announced in recent years,
but only two of these appear to be under active development.

Incremental improvements to conventional technology and commercialization of advanced
geothermal technology, especially that using impervious hot dry rock could greatly increase the
availability of geothermal energy. The timeline for commercial development of advanced
technology, however, is uncertain.

Staff will describe the potential availability, estimated cost of energy and issues associated with
development of the geothermal resources. Presentation materials will be provided prior to the
meeting.


851 S.W. Sixth Avenue, Suite 1100                 Steve Crow                               503-222-5161
Portland, Oregon 97204-1348                    Executive Director                          800-452-5161
www.nwcouncil.org                                                                     Fax: 503-820-2370
Sixth Northwest Conservation & Electric Power Plan

              Geothermal
       Power Generation Resource
              Assessment
                                 Jeff King
           Northwest Power and Conservation Council
                      Power Committee
                                   Boise, ID
                                 March 10, 2009


                                                                                         Northwest
                                                                                          Power and
                                                                                          Conservation
                                                                                         Council




Geothermal energy in the Northwest
Northwest hydrothermal potential
   At one time thought to be very large (thousands of MW)
   Lower expectations in recent years (hundreds of MW??)
Many attempts at development, few successful
   Land use & visual conflicts, esp. in Cascades
   Low probability of locating natural hydrothermal resource (~ 20% success
     rate)
First Northwest geothermal power plant in-service Jan 2008
   Raft River Phase I - 13 MW net
   13 MW Phase II under contract; 13 MW Phase III proposed
Exploratory drilling reported at 5 additional sites1
   Idaho - Willow Springs
   Oregon - Neal HS, OIT, Crump Geyser, Newberry
                             1) Geothermal Energy Association. U.S. Geothermal Power Production
                             and Development Update. March 2009.
                                                                                         Northwest
                                                                                          Power and
                                                                                          Conservation
                                         2                                               Council




                                                                                                         1
 Reported geothermal exploration




                               Neal HS

       Newberry

                                                      Willow
                       Crump Geyser                   Springs
       OIT

                                             Raft River



                                                                Northwest
                                                                 Power and
                                                                 Conservation
                                         3                      Council




 Binary-cycle geothermal plant
Natural hydrothermal reservoir
    • Temperature > 200oF
    • Permeable
    • Fluid (water) present
    • Feasible drilling depth (< 3km)
Hot geothermal fluid is extracted
from reservoir via production wells
Heat is transferred to low boiling
point working fluid in heat
exchanger
Cooled geothermal fluid is re-
injected to reservoir
Vaporized/pressurized working
fluid drives turbine-generator
Working fluid is condensed,
returned to heat exchanger

                                                                Northwest
                                                                 Power and
                                                                 Conservation
                                         4                      Council




                                                                                2
                                                                                          Raft River, ID - 13 MW


                               Reference plant: 40
                               MW binary-cycle
                                    3 x 13 MWnet units
                                    47 MW (gross); 39 MW (net) capacity
                                    Closed-loop binary cycle
                                        Organic Rankine cycle (ORC) technology
                                        No release of CO2 or toxic materials
                                        Full reinjection of geothermal fluid
                                    Air or water-cooled condenser
                                        • Wet cooling - more efficient, more uniform seasonal output
                                        • Dry cooling in water-scarce areas
                                    Modular
                                    Widely-used, mature technology
                                    Can utilize moderate temperature resources


                                                                                                                           Northwest
                                                                                                                            Power and
                                                                                                                            Conservation
                                                                                    5                                      Council




                                    Price year capital cost estimate
                                                                                                 Declining to $3900/kW in 2009
                                    $7,000
Overnight capital cost (2006$/kW)




                                                   Proposed 2008 price year estimate $4200/kW
                                    $6,000
                                                   Stillwater & Salt Wells
                                    $5,000


                                    $4,000


                                    $3,000

                                    $2,000                                                      Raft R.
                                                     Generic Estimates
                                                     Projects
                                    $1,000           CERA PPCI
                                                     Proposed 6 Plan Draft
                                       $0
                                         2003       2004         2005        2006       2007        2008           2009   2010
                                                                        Vintage of Cost Estimate
                                                                                                                           Northwest
                                                                                                                            Power and
                                                                                                                            Conservation
                                                                                    6                                      Council




                                                                                                                                           3
             Capital cost forecast
                                   6th Plan Price Yr (2008)              Real costs decline to ~ 130% of
                                   for 2010 service                      2006 values by 2013 (service yr)
                         $4,500
                                                                              2013 > Constant cost (no
                         $4,000
Overnight capital cost

                                                                              technical learning)

                         $3,500
                         $3,000
     (2006$/kW)




                         $2,500
                         $2,000
                         $1,500
                         $1,000
                          $500
                            $0
                                  2005        2010             2015          2020          2025
                                                   Year of commercial service                                 Northwest
                                                                                                               Power and
                                                                                                               Conservation
                                                                     7                                        Council




              Hydrothermal power plant assumptions
              (2006 dollar values, 2008 price year)
                                                              Binary
                 Net capacity (MW)                             39
                 Heat Rate (Btu/kWh)                          28,500           12% thermal efficiency

                 Availability (%)                              95%             Assm 90% annual CF

                 Overnight capital ($/kW)             $4,200 +/- 25%           Successful development
                                                                               w/ unsuccessful prospects ~ $5800
                 Fixed O&M ($/kW/yr)                          $175             Incl. well field maintenance

                 Variable O&M ($/MWh)                         $4.50
                 Planning                                     36 mo            Geologic assessment, permits &
                                                                               exploratory drilling
                 Early construction                           12 mo            Production drilling

                 Final construction                           24 mo            Power plant construction

                 Earliest new PNW unit                        2010
                                                                                                              Northwest
                                                                                                               Power and
                                                                                                               Conservation
                                                                     8                                        Council




                                                                                                                              4
                                                                                                                                                        IOU financing
                     Hydrothermal geothermal                                                                                                            2020 service

                     costs ca. 2020                                                                                                                     90% CF


                                                    $120
                 L evelized lifecycle 2006$/M W h
                                                                                                                                                                 CO2 (Proposed PRM
                                                    $100                                                                                                         mean value)
                                                                                                                                                                 Transmission &
                                                     $80                                                                                                         Losses
                                                                                                                                                                 System Integration
                                                     $60                                                                                                         Variable Fuel

                                                     $40                                                                                                         Variable O&M

                                                     $20                                                                                                         Fixed Fuel

                                                                                                                                                                 Fixed O&M
                                                        $0
                                                                   Project-only,                  Project-only,                 Including
                                                                                                                                                                 Capital
                                                                     Current                       No Federal                  Unsuccessful
                                                                     Federal                       Incentives                 Exploration, No
                                                                    Incentives                                                  Incentives
                                                                                                                                                                                           Northwest
                                                                                                                                                                                            Power and
                                                                                                                                                                                            Conservation
                                                                                                                         9                                                                 Council




                     Energy resource options
                                                                                                                                       Transmission cost & losses to point of LSE wholesale delivery
                                                                                                                                       No federal investment or production tax credits
                                                                                                                                       Baseload operation (CC, Nuc, SCPC 85%; IGCC, Bio - 80%)

                     Early 2020s                                                                                                       Medium NG and coal price forecast (Draft 6th Plan)
                                                                                                                                       Proposed Draft 6th Plan CO2 price.


                                              $300                                Emission (CO2) cost
Levelized cost (2006$/MWh)




                                                                                  Transmission & Losses
                                              $250                                System Integration

                                              $200                                Plant costs


                                              $150

                                              $100

                                                    $50

                                                        $0
                                                                                                                                                                     SS




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                                                                                                                                                                                           Northwest
                                                                                                                                                                                            Power and
                                                                                                                                                                                            Conservation
                                                                                                                       10                                                                  Council




                                                                                                                                                                                                           5
  USGS assessment of resource potential




                                      Identified geothermal systems are represented by black dots.
                                                                                                     Northwest
                                                                                                      Power and
                                                                                                      Conservation
                                                 11                                                  Council




  Hydrothermal resource potential (MW)1
         Identified      Identified     Identified      Undiscovered      Undiscovered      Undiscovered
            F95            Mean            F5               F95              Mean                F5


ID          81             333             760               427              1872               4937

MT          15              59             130               176               771               2033

OR         163             540            1107               432              1893               4991

WA           7              23              47                68               300               790

Totals     266             955            2044              1103              4836              12751


                 1)   U.S. Geological Survey. Assessment of Moderate and High-Temperature
                      Geothermal Resources of the United States. 2008.
                                                                                                     Northwest
                                                                                                      Power and
                                                                                                      Conservation
                                                 12                                                  Council




                                                                                                                     6
Developable hydrothermal potential
2008 USGS assessment is most current available
Estimate is akin to theoretical potential
    • Excludes inaccessible federal land (e.g., National Parks)
    • Includes all other prospective resources
For planning purposes, developable potential:
    •   Mean Identified Resource + Mean Unidentified resource
    •   Low: 20% of F95 - 300 MW
    •   Expected: 20% of Mean – 1200 MW (WGA near-term 1300 MW)
    •   High: 20% of F5 - 3000 MW
    •   MW = aMW in USGS report (assumed 100% capacity factor)
Historically slow rate of development may limit potential
    •   e.g., 40 MW/yr over period of plan - 800 MW

                                                                        Northwest
                                                                         Power and
                                                                         Conservation
                                             13                         Council




Conclusions: Hydrothermal geothermal
Northwest hydrothermal potential
    Thought to be very large potential at one time
    Cascades volcanic resource less promising than previously thought
    Recent USGS assessment more optimistic for non-volcanic resources
First Northwest geothermal power plant in-service Jan 2008
    Raft River Phase I, 13 MW net
    13 MW Phase II under contract; 13 MW Phase III proposed
Economics appear to be competitive w/ Columbia Basin wind and gas
   combined-cycle
Very high initial investment risk
    High up-front exploration cost (~10% of total plant cost)
    High dry (or cold) hole risk (80%)
Closed-cycle binary technology is becoming technology of choice
    Can utilize moderate-temperature resources
    Negligible releases of CO2 or hazardous materials
    Base load energy production w/sustained peaking capacity value
                                                                        Northwest
                                                                         Power and
                                                                         Conservation
                                             14                         Council




                                                                                        7
Enhanced geothermal systems




                          USDOE, Geothermal Tomorrow 2008    Northwest
                                                              Power and
                                                              Conservation
                     15                                      Council




Subsurface temperature at 3.5 km depth1




                                                  1) 11,500 feet
                                                             Northwest
                                                              Power and
                                                              Conservation
                     16                                      Council




                                                                             8
     Subsurface temperature at 6.5 km depth1




                                                                   1) 21,330 feet
                                                                              Northwest
                                                                               Power and
                                                                               Conservation
                                      17                                      Council




     Areas of special EGS interest
Oregon Cascades
                     Snake R. Plain




     Basin & Range




                                           MIT. The Future of Geothermal Energy. 2004
                                                                              Northwest
                                                                               Power and
                                                                               Conservation
                                      18                                      Council




                                                                                              9
                 USGS Provisional estimate of EGS potential
                 160,000
                              Washington
                 140,000
                              Oregon
                              Montana
                 120,000
                              Idaho
Capacity (MWe)




                 100,000

                                               Current installed PNW
                  80,000                       capacity (57,000 MW)


                  60,000


                  40,000


                  20,000


                      0
                           Identified F50   Undiscovered F50           EGS F50
                                                                                 Northwest
                                                                                  Power and
                                                                                  Conservation
                                               19                                Council




                 Needed for commercial EGS
                 • Methods for increasing production well flow rates
                 • Methods of characterizing the fractured volume
                 • Methods of repairing short-circuits
                 • Methods of understanding the role of existing faults in
                   augmenting or impeding flow
                 • Robust instrumentation for hi-temp down-hole
                   environment
                 • Methods of predicting scaling and deposition
                 • Validation of long-term viability of commercial-scale EGS
                   at several sites


                                                                                 Northwest
                                                                                  Power and
                                                                                  Conservation
                                               20                                Council




                                                                                                 10
Conclusions re: EGS
EGS potential dwarfs that of other renewable resources
EGS potential is widespread
    Potentially far greater siting flexibility than other renewables
    More diffuse, may add to the cost and environmental impact of development
EGS remains commercially unproven
Commercial EGS is likely a decade or more in the future
    Numerous issues need to be resolved through R&D
    Commercial demonstration projects will require several years to be up and running
    Several years of operation likely to be needed to confirm the long-term viability of
       EGS reservoirs
EGS costs likely to be higher than conventional geothermal
    Deeper wells
    Cost of establishing and maintaining fracture system
    Hot, high pressure environment

                                                                                           Northwest
                                                                                            Power and
                                                                                            Conservation
                                             21                                            Council




Possible Sixth Plan action items
EGS pilot projects at areas of special interest unique to the
  Northwest
    • Snake River plain
    • Oregon Cascades
Participation in Basin & Range EGS pilot project




                                                                                           Northwest
                                                                                            Power and
                                                                                            Conservation
                                             22                                            Council




                                                                                                           11

				
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