Recoverable EGS Resource Estimates Susan Petty Black Mountain - - PowerPoint PPT Presentation

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Recoverable EGS Resource Estimates

Susan Petty

Black Mountain Technology Seattle, Washington

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Energy from the Earth’s Heat

Conductive heat energy

– Greater than 3 km – Requires stimulation or other engineering to develop reservoir

Convective heat energy

– Hydrothermal systems – Impermeable or low permeability systems on the edges of hydrothermal systems – Fractured, but may require stimulation or engineering to develop

Hot water co-produced with oil and gas

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Conductive Resource - Base vs. Reserves

Resource Base

– Total heat in place – Between 3 km and 10 km

Reserves

– Economic today – Electric generation – Direct use of heat – EGS has no commercial projects as yet, so no reserves

Recoverable Resource

– Extractable – Conversion efficiency – Recoverable fraction – Accessible – Economics of recovery

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Temperature at Depth

Calculated by SMU Maps of temperature at depth at mid-point of 1km slices Area at each temperature in each depth slice Used to calculate heat in place

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Abandonment Temperature

Assume reservoir rock cooled 10°C Limit for conversion equipment at surface Leaves heat in place for future heat mining with different equipment Resource is sustainable due to enormous quantity of heat in place remaining, or available for recovery by heat mining, Qavailable

Qtotal - Qabandonment = Qavailable

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Recovery Factor

How much of the available heat can we recover?

, , , , , , , ,

[ , , , , , ] ( ) ( ) ( ) ( )

rec r active total r i r a

• total

active r i r a r total r i

• r i

r a r v r i

• Q

F f V V C T T T Q V C T T F V C T T T T F T T

γ γ γ

ρ ρ φ ≡ = − = − − = −

Qrec = recoverable thermal energy content of the reservoir

v

φ = active reservoir volume/total reservoir volume ρ = rock density (kg/m3) Vtotal = total reservoir volume (m3) Vactive = active or effective reservoir volume (m3) Cγ = rock-specific heat (kJ/kg °C) Tr,i = mean initial reservoir rock temperature (°C) To = mean ambient surface or “dead-state” temperature (°C) Tr,a = mean rock temperature at which reservoir is abandoned (°C).

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Fractured Volume

Fractured Volume for EGS Projects Recovery of heat depends largely on fractured volume

– Active heat exchange area – Fracture spacing – Path length between wells – Injector/producer pattern

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Recoverable Heat

Sanyal and Butler, 2005.

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Usable Energy – Converting Heat to Power Heat alone is beneficial. Conversion of heat to power better justifies well cost Heat in kilojoules = heat in kiloWatt-sec Convert heat to electric power

– kW-sec/1000 kW/MW = MWt-sec – MWt-sec/(30 yrs in seconds) – Conversion efficiency MWt x ηth MWe

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Conversion to Electric Power - Cycle Efficiency

Temperature, ˚C Cycle Thermal Efficiency ηth, % 150 11 200 14 250 16 300 18 350 22

5 10 15 20 25 30 50 100 150 200 250 300 Resource temperature, TR/C Thermal efficiency, %

T0 = 30 C T0 = 50 C

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Inaccessible Area

Some areas are inaccessible for development:

– Parks – State and National – Recreation Areas – National Monuments – Wilderness

Subtract inaccessible fraction

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Total Recoverable Power

Depth of Slice, km Power available for slice, MWe Amount at 150ºC, MWe Amount at 200ºC, MWe Amount at 250ºC, MWe Amount at 300ºC, MWe Amount at 350ºC, MWe 3 to 4 122,000 120,000 800 700 400 4 to 5 719,000 678,000 39,000 900 1,200 5 to 6 1,536,000 1,241,000 284,000 11,000 600 6 to 7 2,340,000 1,391,000 832,000 114,000 2,800 7 to 8 3,245,000 1,543,000 1,238,000 415,000 48,000 1,200 8 to 10 4,524,000 1,875,000 1,195,000 1,100,000 302,000 54,000 TOTAL 12,486,000

Total Recoverable Electric Power in Net MWe for 30 Years,

20% Recoverable Fraction of Thermal Energy from the Reservoir

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Total Recoverable Power

Depth of Slice, km Power available for slice, MWe Amount at 150ºC, MWe Amount at 200ºC, MWe Amount at 250ºC, MWe Amount at 300ºC, MWe Amount at 350ºC, MWe 3 to 4 12,000 12,000 80 70 40 4 to 5 72,000 68,000 4,000 90 120 5 to 6 154,000 124,000 28,000 1,100 60 6 to 7 234,000 139,000 83,000 11,000 300 7 to 8 324,000 154,000 124,000 41,000 5,000 120 8 to 10 452,000 187,000 119,000 110,000 30,000 5,000 TOTAL 1,249,000

Total Recoverable Energy in Net MWe for 30 Years

2% Recoverable Fraction of Thermal Energy from the Reservoir

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Economic Modeling

Two models used:

– GETEM – Geothermal Electricity Technology Evaluation Model

• U.S. DOE developed new cost of power modeling tool
• GETEM allows comparing cost of power with current

technology to cost with improved technology.

– MIT EGS model

• Updated for 2004 costs
• Similar costs to GETEM for all but the highest cost resources
• Can optimize costs for depth and temperature

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Economic Modeling-GETEM

GETEM Version: BINARY Case Name: File Name:

Baseline Change Improved

Case Date:

1/8/2007

2005 2015 17.32

• 63%

6.44 Input

Baseline Change Improved

Global Economic Parameters

Fixed.Charge.Rate

Ratio

0.128 1.00 0.128 Utiliz.Factor

Ratio

0.95 1.00 0.95 Contingency

%

5% 1.00 0.05

Input parameters

Temperature of GT Fluid in Reservoir

Deg-C

200 1.00 200 Plant Size (Exclusive of Brine Pumping)

MW(e)

500.0 1.00 500.00

Number of independent power units

10 0.50 5.00 Brine Effectiveness (exclusive of brine pumping)

Calculate Y or N

Y Y

If N (no), enter value in cell C19 and/or E19

W-h/lb

8.00 1.00 8.00 Calculated Brine Effectivenss

W-h/lb

10.86 1.25 13.57 Brine Effectiveness

W-h/lb

10.86 13.57

Apply improvement to reducing flow requirement or increasing power output

F - flow or P - power

F

Plant Cost

Calculate Y or N

Y Y

If N (no), enter value in cell C24 and/or E24

$/kW

1,800 $ 1.00 1,800 $ Calculated Plant Cost

$/kW

1,551 $ 0.75 1,006 $ Plant Cost

$/kW

1,551 $ 1,006 $ Wells Cost Curve: 1=Low, 2=Med, 3=High 4 1.00 3 PRODUCTION WELL Depth Feet 13,123 1.00 13,123 Estimated Cost, from SNL Curve $K/well $6,955

• $6,955

User's Cost Curve Multiplier ratio 1.000 1.000 Producer, Final Cost $K/well $6,955 0.75 $5,216 INJECTION WELL Depth Feet 13,123 1.00 13,123 Estimated Cost, from SNL Curve $K/well $6,955 $6,955 Injector, Final Cost $K/well $6,955 0.75 $5,216

Cost of Electricity, cent/kWh

BINARY SYSTEM INPUT SHEET GETEM-2005-A3 (dje-July-06-05) EGS-AC binary-200C-4km-2015-July 18 2005 GETEM-2005-EGS- 150C 2015-sp-1C-July 18 05 TIO TIO

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Supply Curve for U.S. Conductive EGS

Supply Curve for EGS Power in the United States

0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

Developable Power Over 30 Years in GWe Cost in Cents per Kw/h

Incremental Improvements Base Cost

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Supply Curve for EGS Power

Range of EGS Supply at Cost

5.0 10.0 15.0 20.0 25.0 30.0 100,000 200,000 300,000 400,000 500,000 600,000 700,000 800,000 900,000 1,000,000

Supply of Power in MWe for 30 Yrs Cost of Power in cts/kWh Median 25% Probability 75% Probability

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Cost - Sensitivity to Resource Variables

Tar get For eca st: LCOE 3.5 km 250C

Flow per well gpm

• .86

Thermal decline %/year .41 Production Well Depth in Feet .12 Project size MW(e)

• .08

Injection Well Depth in Feet .06 Resource Temp. Deg-C

• .04
• 1
• 0.5

0.5 1 Measured by Rank Cor relation

Sensitivity Chart

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Convective vs. Conductive Resource Above 3 km

– High temperature fluids – Permeability often controlled by faults and fractures – Rock heated by convection of hot water

Hydrothermal resource – very high permeability Shallow EGS resource

– On margins of hydrothermal systems – Volcanic heating

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Hydrothermal and EGS Associated with Hydrothermal

Supply of Geothermal Power Available at Cost

5 10 15 20 25 30 5,000 10,000 15,000 20,000 25,000 30,000 35,000

Cumulative Power Available at or below Cost in MWe Break-even Levelized Cost of Power in cts/kW-hr In 2004 $

Hydrothermal power exclusive of land withdrawn from development

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Technology Improvement Impact on Cost of Power

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Market Penetration of EGS Power

Year

5 10 15 20 25 30 35 40 45 50

Break-Even Price (¢/kWh)

1 2 3 4 5 6 7 8 9 10

Cumulative EGS Capacity Scenario (MWe)

20000 40000 60000 80000 100000 Competitive Market Price EGS Break-Even Price EGS Capacity Scenario

Assumes:

• Learning curves

starting from 60 kg/s/prod.

• Technology

improvement based on US Federal spending

• f $216 million.
• Uses MIT model and

assumptions for learning curves

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Cost of Power from Co-Produced Fluids

GETEM Version: BINARY Case Name: File Name:

Baseline Change Improved

Case Date:

1/4/2007

2005 2010 15.02

• 61%

5.86 Input

Baseline Change Improved

Global Economic Parameters

Fixed.Charge.Rate

Ratio

0.080 1.00 0.080 Utiliz.Factor

Ratio

0.95 1.00 0.95 Contingency

%

5% 1.00 0.05

Input parameters

Temperature of GT Fluid in Reservoir

Deg-C

135 1.00 135 Plant Size (Exclusive of Brine Pumping)

MW(e)

5.0 2.00 10.00

Number of independent power units

10 0.20 2.00 Brine Effectiveness (exclusive of brine pumping)

Calculate Y or N

Y Y

If N (no), enter value in cell C19 and/or E19

W-h/lb

5.00 1.00 5.00 Calculated Brine Effectivenss

W-h/lb

3.12 1.20 3.74 Brine Effectiveness

W-h/lb

3.12 3.74

Apply improvement to reducing flow requirement or increasing power output

F - flow or P - power

P

Plant Cost

Calculate Y or N

N N

If N (no), enter value in cell C24 and/or E24

$/kW

2,150 $ 0.85 1,828 $ Calculated Plant Cost

$/kW

5,038 $ 0.85 2,992 $ Plant Cost

$/kW

2,150 $ 1,828 $

Cost of Electricity, cent/kWh

BINARY SYSTEM INPUT SHEET GETEM-2005-E2-(dje-Feb-01-06) BINARY Poplar Dome Wells of Opportunity EGS METEG- Poplar EGS Wells of Opp Jan 07

Wells of Opportunity

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Cost of Power from Co-Produced Fluids

GETEM Version: BINARY Case Name: File Name:

Baseline Change Improved

Case Date:

1/4/2007

2005 2010 8.12

• 56%

3.54 Input

Baseline Change Improved

Global Economic Parameters

Fixed.Charge.Rate

Ratio

0.080 1.00 0.080 Utiliz.Factor

Ratio

0.95 1.00 0.95 Contingency

%

5% 1.00 0.05

Input parameters

Temperature of GT Fluid in Reservoir

Deg-C

135 1.00 135 Plant Size (Exclusive of Brine Pumping)

MW(e)

50.0 3.00 150.00

Number of independent power units

10 0.20 2.00 Brine Effectiveness (exclusive of brine pumping)

Calculate Y or N

Y Y

If N (no), enter value in cell C19 and/or E19

W-h/lb

5.00 1.00 5.00 Calculated Brine Effectivenss

W-h/lb

3.12 1.20 3.74 Brine Effectiveness

W-h/lb

3.12 3.74

Apply improvement to reducing flow requirement or increasing power output

F - flow or P - power

P

Plant Cost

Calculate Y or N

N N

If N (no), enter value in cell C24 and/or E24

$/kW

2,150 $ 0.85 1,828 $ Calculated Plant Cost

$/kW

3,179 $ 0.84 1,866 $ Plant Cost

$/kW

2,150 $ 1,828 $

Cost of Electricity, cent/kWh

BINARY SYSTEM INPUT SHEET GETEM-2005-E2-(dje-Feb-01-06) BINARY Poplar Dome Enhanced Wells of Opportunity EGS METEG- Poplar EGS Wells of Opp Jan 07

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Geothermal Energy from Oilfields

Heat included in conductive resource if deeper than 3 km.

– Dissolved methane not calculated – Geopressured resource – kinetic energy not included

Deep sedimentary basins Co-produced hot water with oil and gas Large amounts of available data Wells of opportunity

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Modeling Geothermal Market Penetration

Uses National Energy Modeling System – NEMS NEMS makes assumptions about technology learning curves, cost escalation. Demand based on projections from utilities in each of the federal regions. Each technology, ie, pulverized coal, solar thermal, PV, wind, geothermal, etc. has it’s own submodule to provide supply input and predict technology improvement

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Supply Input for Geothermal Submodule of NEMS

Geothermal Supply (US)

Updated v. GPRA06

20 40 60 80 100 120 140 160 180 200

• 10

20 30 40 50 60 70 80 90 100 110 120 130 Cumulative Capacity (GW) LCOE (2004$/MWh)

GPRA06 - Hydrothermal GPRA06 - Total Updated - Hydrothermal Updated - Total GPRA06 - EGS Updated - Co-produced Updated - EGS

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Supply Input for Geothermal Submodule of NEMS

Geothermal Supply - Total (US)

Updated v. GPRA06 20 40 60 80 100 120 140 160 180 200

• 10

20 30 40 50 60 70 80 90 100 110 120 130 Cumulative Capacity (GW) LCOE (2004$/MWh)

HT F HT B CoP CoP EGS Conv EGS Cond EGS Conv HT F HT B HT F EGS Conv/ Cond HT F/ B HT F/ B EGS Cond

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Supply Input for Geothermal Submodule of NEMS

Geothermal Supply - Hydrothermal Western Regions

Updated v. GPRA06

$- $1,000 $2,000 $3,000 $4,000 $5,000 $6,000 $7,000 $8,000 $9,000 $10,000

• 5

10 15 20 25 30

Cumulative Capacity (GW) Capital Cost (2004$ /kW)

GPRA06 - Total GPRA06 - NWP (11) Updated - Total Updated - NWP (11) GPRA06 - RA (12) GPRA06 - CAL (13) Updated - RA (12) Updated - CAL (13)

EGS Assessment Study

Aug 2005 – Sept 2006

The Future of Geothermal Energy

Forcast Geothermal Capacity from NEMS

Forecast Geothermal Capacity

5 10 15 20 25 30 35 AEO 06 GPRA06 GPRA08 AEO 06 GPRA06 GPRA08 AEO 06 GPRA06 GPRA08 AEO 06 GPRA06 GPRA08 AEO 06 GPRA06 GPRA08 2010 2015 2020 2025 2030

Year Capacity (GW)

NWP (11) RA (12) CAL (13) ERCOT (2) SERC (9) SPP (10) Western Non- Western