Cost Estimates of Stationary Fuel Cell Systems

Brian D. James Andrew B. Spisak Whitney G. Colella

7 November 2012

Important question facing industry: Capital costs are lower when manufacturing (A) many low power systems or (B) fewer high power systems?

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Presentation Outline


Scope of Work
Methodology
System Definitions
Representative Cost Details
System Cost Comparisons

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Scope of Work
Work conducted under contract to the National Renewable Energy Laboratory (Dr. Bryan Pivovar) under the direction of DOE/EERE (Mr. Jason Marcinkoski)


Builds on past Strategic Analysis Inc./Directed Technologies Inc. cost analysis work for automotive fuel cells and H2-related systems


Uses a Design-for-Manufacturing-and-Assembly (DFMA) capital cost methodology


Examines Stationary Fuel Cell Systems (FCS) • • • • •

Operating on Natural Gas Combined Heat and Power (CHP) applications System net electric powers of 1, 5, 25 and 100 kilowatt-electric (kWe) System annual production rates of 100, 1k, 10k, and 50k Three fuel cell technologies: – low temperature (LT) proton-exchange membrane (PEM) – high temperature (HT) PEM – solid oxide fuel cell (SOFC) technologies. • Meant to be complete system cost (defined on next page)

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System Terminology
Fuel Cell(FC) Subsystem
Stack: fuel cell stack including its assembly
FC Balance of Plant (BOP): peripheral components assoc. w/ the FC subsystem. (includes controls)
Assembly: integration of the stack with the BOP components


Fuel Processing(FP) Subsystem
Reactor: external fuel reforming: integrated reactor does the fuel/air preheat, reforming, & shift. Includes assembly of the reactor.
FP BOP: peripheral components assoc. w/the FP subsystem. (includes controls)
Assembly: integration of the reactor with the BOP components


Power Electronics Subsystem
Components required for power regulation and system control: voltage regulation, overall system control, batteries.


Combined Heat & Power (CHP) Subsystem
Components required for use of system waste heat as heat supply for building use.


Housing and Final System Assembly
Cost Margin 5


10% cost markup to cover non-enumerated components or processes
Adding a margin follows judicious cost estimation practice, particularly in preliminary costing exercises. 5

Process-Based Cost Estimation: DFMA®-Style Costing Methodology What is DFMA?
DFMA® (Design for Manufacturing & Assembly) is a registered trademark of Boothroyd-Dewhurst, Inc. • •

Used by hundreds of companies world-wide Basis of Ford Motor Co. design/costing method for the past 20+ years


SA practices are a blend of: •

“Textbook” DFMA®, industry standards and practices, DFMA® software, innovation, and practicality

Estimated Cost = (Material Cost + Processing Cost + Assembly Cost) x Markup Factor Manufacturing Cost Factors: 1. 2. 3. 4.

Material Costs Manufacturing Method Machine Rate Tooling Amortization

Methodology Reflects Cost of Under-utilization: Initial Expenses

Capital Cost Installation

Maintenance/Spare Parts Utilities Miscellaneous Annual Capital Repayment

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Operating Expenses

Annual Operating Payments

Used to calculate annual capital recovery factor based on: • Equipment Life • Interest Rate • Corporate Tax Rate

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Machine Rate ($/min)

Annual Minutes of Equipment Operation

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Application of DFMA Methodology


DFMA applied to key components: • Fuel cell stacks • Fuel processing reactor • Assembly of stacks, reactor, and system


Alternate methods used for everything else • Price quotes • Scaling factors for flow rates changes • Exponential learning factor coefficients for production scale changes • Analogies to similar components • Focus placed on “key” rather than “minor” components

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Approach: Cost Factors Included in Estimates Not Included in Cost Analysis •

• • • •

Markup for primary Power System manufacturer/assembler (G&A, scrap, R&D, profit) Non-recurring RD&E costs Warranty Advertising Taxes

Profit One-Time Costs

Cost Excluded from SA Analysis

General Expenses

OEM Price

Included in Cost Analysis Fixed Costs • Equipment depreciation • Tooling amortization • Utilities • Maintenance Variable Costs • Direct Materials used in manufacturing • Direct Materials purchased from suppliers • Manufacturing scrap • Manufacturing labor • Assembly labor

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Factory Expenses Direct Materials

Cost Included in SA Analysis

Direct Labor

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Example of Process Flow Diagram for SOFC System

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Additional Key Assumptions (for all three technologies) FCS Capital is highly dependent on specific application and configuration.
Natural Gas supply pressure
For 1 kWe and 5kWe systems:
Assume residential application with 1 psig NG supply pressure
Thus requires a NG compressor


For 25kWe and 100kWe systems
Assume commercial application with 15 psig NG supply pressure
Thus requires only a pressure regulator


Design for Water-Neutral Operation
System assumes an initial charge of de-ionized (DI) water
A flue gas condenser is used to recover all future system water needs
Reactor scaling and modularity
Reactor scaled for 1, 5, and 25 kW systems
For 100kW system, four 25kW reactors are used
Desulfurization
Based on TDA Sulfa Trap-R3 pellet bed desulfurizer (not hydro-desulfurization)
Two beds in parallel for rapid, non-interrupted change-out
Periodic bed replacement 10

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Additional Key Assumptions (for all three technologies)
Combined Heat and Power (CHP) operation
System configurations assumes recoverable heat from the reactors
For 1kWe Systems
Gas/Gas Heat exchanger (Reactor Flue Gas to Building Air Heating)


For 5/25/100 kWe Systems:
Gas/Liquid Heat exchanger (Reactor Flue Gas to Building Hydronic Heating)


Power Management
Baseline requires Grid-Connection for start-up
Produces 120VAC (also 240VAC for 25 & 100 kW systems)
92% DC-to-AC Inverter efficiency (for all power levels)
System Housing
NEMA 4, powder-coated metal housing
Cost based on quotes
System Degradation
Cost and System Life are treated as independent variables
All system are oversized by 20% at Beginning-of-Life(BOL) to allow for full power after degradation 11

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Example of Reactor Design (for HT PEM)

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Key Features:
High thermal integration
Concentric design modeled on Tokyo Gas* concept
Natural Gas Steam Reforming
Combines HX and functions for SMR, WGS, & PROX (for Low-Temp PEM).
Catalyst on metal monoliths
Designed for rapid assembly and low cost

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Stack Technology Comparisons LT PEM

HT PEM

SOFC

80 °C

160 °C

800 °C

Coated stamped Stainless-steel bipolar plates, planar

Coated stamped Stainless-steel bipolar plates, planar

Planar, tape-cast, anode-supported ceramic electrodes

Automotive PEM, (PRIMEA MEA on reformate)

Automotive PEM, (PBI MEA)

NexTech /CFCL

Performance Reference

Gore Primea

Advent Technologies

FCE/Versa Power

Power Density

408 mW/cm2

240 mW/cm2

291 mW/cm2

(at 0.676 V/cell)

(at 0.6 V/cell)

(at 0.8 V/cell)

~1.2 atm

~1.3 atm

~1.2 atm

0.4mgPt/cm2

1.0mgPt/cm2

Ni-Co/LSCF

SR, WGS, PROX

SR, WGS

SR

No

No

Minor internal WGS/SR

Exhaust Gas: 240°C Stack Coolant: 75°C

Exhaust Gas: 280°C Stack Coolant: 150°C

Exhaust Gas: 190°C

HHV: 31% LHV: 35%

HHV: 30.5% LHV: 34%

HHV: 49% LHV: 55%

Operating Temperature Stack Design Design Reference

Pressure Catalyst Loading Reforming Internal Reforming CHP Supply Design Efficiency 13

(effective 100% reformation of NG to H2)

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Capital costs decrease with increasing system power and with increasing production rate.

SOFC Systems 100 sys/yr 1,000 sys/yr 10,000 sys/yr 50,000 sys/yr 14

1 kWe $11,830 $6,786 $5,619 $5,108

5 kWe $3,264 $2,168 $1,862 $1,709

25 kWe $981 $671 $599 $570

SOFC System Cost Results, $/kWnet electric

100 kWe $532 $440 $414 $402 14

At low power (~1 to 5kWe), capital cost drivers include both fuel cell and fuel processing subsystems.

At production levels of 1,000 sys/yr and above, the FP subsystem is the greatest contributor to capital cost. 15

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At high power (~100kWe), the primary capital cost driver is the fuel cell subsystem.

The fuel processor subsystem cost does not scale down well at low powers.

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Within the FP subsystem, FP BOP costs dominate at all scales and production levels.

The reactor, due to its integrated nature and simplified SOFC configuration, is not very costly.

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At low production rates, FP BOP costs are dominated by compressors, pumps, sensors, & heat exchangers.

At low power, the NG compressor is a major FP BOP contributor (assumed to not be needed at high power). At high power, the water pump and condenser are dominant. System refinement is desired to minimize these elements. 18

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For same cumulative global installed capacity, higher power systems are more economical per unit of electric power.

100% electrical and heat utilization is assumed for all systems: in practice, smaller systems may have higher utilizations. Results may change when life cycle costs (LCCs) are considered -• a higher heat utilization for lower power systems may be observed, along with higher revenues from this heat. 19

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Grid-independent and CHP capability adds only ~10% to total capital costs.

Baseline system contains no batteries for load-leveling, transients, or system start-up. Components to add these capabilities are