EERE PowerPoint 97-2004 Template: Green Version · Total Project Funding: $250k May 11, 2015 ......
Transcript of EERE PowerPoint 97-2004 Template: Green Version · Total Project Funding: $250k May 11, 2015 ......
1 | US DOE Geothermal Office eere.energy.gov
Public Service of Colorado Ponnequin Wind Farm
Geothermal Technologies Office 2015 Peer Review
Geothermal Systems Engineering
GT-Mod
Thomas Lowry
Sandia National Laboratories
Systems Analysis Project Officer: Timothy Reinhardt
Total Project Funding: $250k
May 11, 2015
This presentation does not contain any proprietary
confidential, or otherwise restricted information. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin
Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.
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Pro
du
ction
Tem
pe
ratu
re [K
]
Production Temperature as f(Well Distance)
5 %
25 %
50 %
75 %
95 %
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LCOE [c/kW-hr]
Cum
ula
tive p
robabili
ty
Resource Temperature = 275 C
2 | US DOE Geothermal Office eere.energy.gov
Relevance/Impact of Research
GT-Mod is a systems-based model of geothermal energy
production that simulates system and sub-system
interdependencies and feedbacks to capture non-linear coupled
responses to uncertainties in one or more input values. This
approach allows users to:
• Produce probabilistic output of economic and physical performance as a
function of uncertainty and various system configurations
• Conduct probabilistic risk assessment to identify and prioritize technology
development strategies
• Optimize system design and operation
• Answer ‘what if’ questions with regards to technology advancement,
system design, and thermal performance
3 | US DOE Geothermal Office eere.energy.gov
• Impacts
– Allows us to gain insight in an environment of uncertainty
– Lowers risks and costs of development
– Identifies and prioritizes areas where improvements and/or better understanding
will impact the bottom line the most
• Innovation
– System dynamics: combines realistic, physics based simulations at the
component level to simulate total system performance
– Risk assessment addresses the always-constant uncertainties to produce
probabilistic output of total system performance
– Modular architecture can be easily extended and adapted to other problems or
other analyses: 2015 work is being extended to direct use applications
• Challenges
– How to include ‘realistic’, physics based simulations in a system dynamics model?
– Connect physical performance with economic performance
– How do we define uncertainty?
Relevance/Impact of Research
4 | US DOE Geothermal Office eere.energy.gov
Scientific/Technical Approach
Geothermal Energy as a Complex System of Systems
• Systems are interdependent
• Each are linked and considered simultaneously
• Focus is on dynamic complexity
Inflow
System
Heat
Conversion
System
Outflow
System
Injection
System
Heat
Extraction
System
Production
System
System ‘A’ System ‘B’
5 | US DOE Geothermal Office eere.energy.gov
Scientific/Technical Approach
Inflow Pipes Outflow PipesPower Plant
Production Wells
Reservoir
Ambient Conditions
GringartenCarslaw and Jaeger
Injection Wells
Production Well Casing Design Injection Well Casing Design
Production Well Heat Transfer
Stochastic Lookups
Injection Well Heat Transfer
From high-resolution reservoir simulations
Adding binary power plant module for 2015
GETEM
6 | US DOE Geothermal Office eere.energy.gov
Scientific/Technical Approach
Use of SYSTEM DYNAMICS (SD)
• SD is a formal modeling discipline that captures the dynamic complexity between connected systems and sub-systems
• Dynamic complexity is a function of direct influences, feedback, and delays
• SD is scalable to the spatial or temporal scale of interest
Evaporator1.5 MPa
Preheater1.5 MPa
Turbine/Generator
85% Isentropiceff.
Condenser320K
ProductionWell
InjectionWell
To CoolingTower
Pump75% Isentropic
eff.
FromCoolingTower
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2
4
5
6
A
B
C
Dynamic complexity example from new binary power plant module
7 | US DOE Geothermal Office eere.energy.gov
Scientific/Technical Approach
• Mathematically,
uncertainties are expressed
as PDF’s (probability
distribution functions)
• They are a reflection of what
we don’t know
• Uncertainty is not
necessarily a 1:1 transfer
between independent and
dependent variables
• Uncertainty = Risk
Truncated Normal
Normal
Triangular
Uniform
Exponential
Uncertainty and Risk
8 | US DOE Geothermal Office eere.energy.gov
Scientific/Technical Approach
• Risk is the consequence
times the probability:
• Consequences can be defined in
many different ways
• User defines PDF’s and
consequence
• Output is probabilistic
• Allows for answering ‘inverse
questions’:
– Given a set of uncertainties, what is
the probability that you will hit your
target?
– What do we need to know better to
have a XX% chance of reaching our
target?
Risk Assessment
t n
nPtnCR )(),(
R = risk, C = consequence, P = probability,
n = # of probability intervals, t = time
Pro
bab
ility
LCOE [¢/kW-hr]
9 | US DOE Geothermal Office eere.energy.gov
Accomplishments, Results and Progress
AOP Objectives
• The objective for FY15 is to continue the advancement and maturing of GT-Mod to support the DOE GTO in its work with regards to the Quadrennial Technology Review, the Geothermal Vision Study, and other needed analyses as directed. Development work will focus on additional functionality as needed to complete the various analyses as well as increasing the general usability and usefulness of GT-Mod to allow for broader adoption and application of the tool in out years.
• Complete validation analysis for ad hoc “what-if” analysis as defined by the program
• Complete analyses for the DOE GTO’s vision study as defined by the office
Screen shot of GT-Mod modeling platform.
10 | US DOE Geothermal Office eere.energy.gov
Accomplishments, Results and Progress
• Project has transitioned from
development phase to analysis phase
• Developed and presented dimensionless
parameter approach for reservoir
performance simulation
• Developed Laplace Transform inversion
for use in SD models
• Created lookup table interface that allows
the model to use high resolution reservoir
simulations
• Created stand-alone power plant model to
be integrated later this year
• 10 conference presentations/proceedings,
1 journal article, 1 in review
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LCOE [c/kW-hr]
Cum
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tive p
robabili
ty
Resource Temperature = 275 C
25 kg/s
50 kg/s
Influence of thermal drawdown solution method on uncertainty
and risk for 50 and 25 kg/s flow rates at 275 oC. The red line is
the Gringarten analytical solution and the blue line is the annual
drawdown rate method.
11 | US DOE Geothermal Office eere.energy.gov
Accomplishments, Results and Progress
• Reservoir modeling with FEHM
• Fracture properties – Dip (5o, 18o, & 80o)
– Strike (80o, 10o)
• Pumping Rates (60, 90, 120, 150, 200 kg/s)
• Well Separation Distance (390, 600, 800 m) Dip Relative to Well-Pair Plane
Strike Relative to Well-Pair Plane
Comparing horizontal, inclined, and vertical well
orientations
12 | US DOE Geothermal Office eere.energy.gov
Accomplishments, Results and Progress
• Horizontal wells are economically
equivalent to the other
configurations (for scenarios
tested)
• Because the thermal
performance of horizontal wells is
more consistent across the
different scenario’s, the economic
risk is reduced
• Pumping requirements for
horizontal wells may be higher in
low, fracture-dip formations
• Results indicate that there may
be an optimal relationship
between fracture strike and dip
and well orientation
• Stimulating the reservoir will help
reduce pumping costs but not
improve thermal performance
13 | US DOE Geothermal Office eere.energy.gov
Future Directions
• Extend the focus of GT-Mod beyond EGS to examine deep direct use
applications
– Power plant module
– Add economic calculations for LCOH
– Add other comparison metrics (e.g. equivalent power, CO2 offset, etc.)
• For power plant module
– Add ability to use different working fluids (currently isopentane only)
– Add ability to optimize plant design
– Expand to more complex systems (out years)
• Analysis
– Revisit reservoir simulations for horizontal well analysis
– Examine combined EGS and direct use systems
– Support GTO in vision study analyses as needed
14 | US DOE Geothermal Office eere.energy.gov
Mandatory Summary Slide
GT-Mod allows users to:
• Produce probabilistic output as a function of uncertainty
• Conduct probabilistic risk assessment to identify and prioritize technology
development strategies
• Optimize system design and operation
• Answer ‘what if’ and inverse questions
Extending functionality to look at direct use in both standalone
and co-generation systems
Main role is in support of the GTO for analyses as needed