Fuel Cell Power Model for CHP anEconomics and Performance Ana

Darlene Darlene & Mike PeMike PeNationaEnergy March 3NREL/PR-5

NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by th

This presentation does not contain any proprietary, confidential, or otherwise 
Outline

Fuel cell basics 

Costs and incentive values presentation were develop

F l C ll Fue demonstration purpose on

l Cell 

Power Model introduction

Dairy case study/tutorial
Fuel Cell Basics
S O SO C

Fuel Cell General Types

• Proton Exchange (PEM) 

– membrane fuel: H2 – system fuel: hydrogen, low CO syngas 

• Phosphoric Acid (PAFC) 

– membrane fuel: H2 – system fuel: syngas 

• Solid Oxide (SOFC) 

– membrane fuel: H2, CO, CH4 

• Molten Carbonate (MCFC) 

– membrane fuel: H2, CO, CH4 

• Others: 

– direct methanol (DMFC) – alkaline (AFC) 
MCFC Basics

Schematic of MCFC operation (EG&G Technical Service
MCFC System Configuration
Fuel Cell Power Model Introdu
FCpower Model

http://www.hydrogen.energy.gov/fc_power_analysis.h

1. WARRANTY DISCLAIMER. THE SOFTWARE IS SUPPLIED "AS IS" WITHOUT WARRANTY OF ANY KIND. THE COPYRIGSTATES, THE UNITED STATES DEPARTMENT OF ENERGY, AND THEIR EMPLOYEES: (1) DISCLAIM ANY WARRANTIES, INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PUINFRINGEMENT, (2) DO NOT ASSUME ANY LEGAL LIABILITY OR RESPONSIBILITY FOR THE ACCURACY, COMPLETENESOFTWARE, (3) DO NOT REPRESENT THAT USE OF THE SOFTWARE WOULD NOT INFRINGE PRIVATELY OWNED RIGHTHAT THE SOFTWARE WILL FUNCTION UNINTERRUPTED, THAT IT IS ERROR-FREE OR THAT ANY ERRORS WILL BE CO2. LIMITATION OF LIABILITY. IN NO EVENT WILL THE COPYRIGHT HOLDER, THE UNITED STATES, THE UNITED STATES OR THEIR EMPLOYEES: BE LIABLE FOR ANY INDIRECT, INCIDENTAL, CONSEQUENTIAL, SPECIAL OR PUNITIVE DAMAINCLUDING BUT NOT LIMITED TO LOSS OF PROFITS OR LOSS OF DATA, FOR ANY REASON WHATSOEVER, WHETHER INCLUDING BUT NOT LIMITED TO LOSS OF PROFITS OR LOSS OF DATA, FOR ANY REASON WHATSOEVER, WHETHER 

ON THE BASIS OF CONTRACT, TORT (INCLUDING NEGLIGENCE OR STRICT LIABILITY), OR OTHERWISE, EVEN IF ANY OWARNED OF THE POSSIBILITY OF SUCH LOSS OR DAMAGES. 
Overview of Combined Heat & Pow

Concept 

Electricity Power 

Natural Gas Heat 

Natural Gas Natural Gas 

or Biogas Fuel Cell 

Excess power genera

the fuel cell is fed to 

National Renewable Energy Laboratory 9 
Dispatch Sequence for Electricity Gene

INPUTS ENERGY CONVERSIONS 

Fuel peak burner 

heat sink 

Water

Fuel FC SYSTEM + H2 

Water Fuel 

H

Grid 

H2-s

electrolyzer 

Sun/WindSun/WindSun/Wind Sun/Wind renewables

Grid 

2 

National Renewable Energy Laboratory 10 
Dispatch Sequence for Electricity Gene

INPUTS ENERGY CONVERSIONS 

Fuel peak burner 

heat sink 

use minimal fuel 

cell power 

use additional 

fuel cell power 

Water

Fuel FC SYSTEM + H

2

Water 

Fuel 

2 

1 2 

H

use grid 

Grid 

H2-s

electrolyzer 

Sun/WindSun/WindSun/Wind Sun/Wind renewables

Grid 3 

National Renewable Energy Laboratory 11 

2 
Technology Selection for Hourly Energ

INPUTS ENERGY CONVERSIONS 

Fuel peak burner 

heat sink 

Water 

Fuel FC SYSTEM + H2 

H

Grid 

Sun/Wind 

renewables 

H2-s

electrolyzer 

2 

National Renewable Energy Laboratory 12 
t t

E ectric ty Demand (kW)Heat Demand (kW)Hydrogen Demand (kW)

Electricity Demand (kW)Heat Demand (kW)Hydrogen Demand (kW) Electric ty Demand (kW)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

ydrog (k )

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Heat Demand (kW)Hydrogen Demand (kW)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24

Electricity Demand (kW)Heat Demand (kW)Hydrogen Demand (kW)

Integration of Demand Profiles, Renewables AGrid Cost Structure 

6 8 

10 12 14 

l i 

6 8 

10 12 14 

8 

10 12 14 

i 

10 12 14 

El i i D d (kW) 

10 12 14 

HOURLY DEMANDS 

Enter Process Specific(default values will be 

Download or enter hourly dema

0 2 4 

0 2 4 6 H en Demand W 

0 2 4 6 

0 2 4 6 8 

0 2 4 6 8 Electricity Demand (kW) 

Heat Demand (kW) Hydrogen Demand (kW) 

Download or enter hourly demaDownload or enter hourly renewEnter grid electricity price profil

Enter equipment capital costs Enter equipment capacity, oper

operating costs 

heat sink 

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 p g 

peak burner 

FC SYSTEM + H2 PRICE SCHEDULES 

electrolyzer 

H2-FC 

Renewables H2-storage 

• Grid electricity ( y) (hourly)• Fuel prices • Water price 

National Renewable Energy Laboratory 13 
Y

FCPower Model Hourly Energy Analys

New Hourly Energy 

Feed 

and 

Utility 

Prices 

Hourly 

Solar 

Wind 

Profiles 

Ye

Financial 

Inputs 

New Hourly Energy Supply & Demand Analysis Module 

Physical Cost 

Electricity 

Heat 

Hd 

e

CF

An

Property 

Data 

Cost 

Inputs Hydrogen Demand 

Profiles 

Energy analysis done for 

8,760 h of one year 

H2A model inputs 

H2A database 

National Renewable Energy Laboratory 14 

User inputs 
Biogas Case Study
System Being Considered

Gas Cle

Plug 

-flow

anaerobic 

digester

Fuel C

1,000 cows 

Solids 

Separation

(bedding + fertilizer)
Methane Sources in the Sacrame

• About 5.5 M

could be gen

digester met

• Rule of thum

1 cow = 200 W 

National Renewable Energy Laboratory 17 
Flow

Quick Start – 4 steps

Title 

Title: Molten Carbonate Fuel Cell Case Study 

Authors: Darlene Steward, Mike Penev 

Contact: Darlene Steward 

Contact phone: 303 275 3837 

Contact e-mail: darlene_steward@nrel.gov 

Organization: NREL 

Date: 1-Aug-09 

Web site: 

Process 

Flow 

Click Process 1 Flow Diagram 

Diagram 

• Fill out Input Sheet completely• Click Run Hourly Energy Profile 3 button

2 • Configure system • Click Input sheet button 

Fuel 

INPUTS 

Burner 

Heat sink 

SELECT ENERGY SUBSYSTEMS & RUN OPTIONS 

Grid 

Water 

Fuel 

Sun 

Fuel cell system + PSA 

PV 

Electrolyzer 

H2-FC 

H2-storage 

System Component Selection 

Wind Turbines 

Electricity 

OUTPUTS 

Heat 

Hydrogen 

TRUE TRUE 

FALSE 

Peak Burner Fuel Cell System Electrolyzer 

Input Sheet 
Economic Evaluation of a Fuel Cell at a 

Hypothetical facility profile: 

• 1,000 cows housed in a free-stall barn 

Biogas system: 

• Manure collection 

• Plug-flow anaerobic digester • Biogas collection and purification • Digester waste press separator Digester waste press separator 

• Windrow composting of solids • Field application of water 

F l ll t Fuel cell sys

tem: 

• Molten carbonate fuel cell (MCFC) produces electri• Electricit

ynot used on site is fed to the 

g rid

National Renewable Energy Laboratory 19 
Information Needed

Capital cost, O&M, Life, Performance

- Digester- Gas cleanup- Fuel cell system

Incentives Incentives 

- Federal incentives- State incentives

On-site energy demands 

- Electricity hourly- Heat hourly 

(includin

g di y( gester

)

Energy costs 

- Electricity ¢/kWh- H $/MMBTU Heat $/MMBTU 
Energy & Material Values

Units V

Methane production Btu CH4/day/ cow (kWh 

CH4/day/cow) 

4

Electricity production (assuming 45% average electrical efficiency for fuel cell) 

kWh/day/cow ~

Usable heat production (assuming 75% total efficiency for fuel cell) 

kWh/day/cow ~

Finished compost Cubic yards/year/ cow 3Electricity required for digester operation 

kWh/cow/day ~

Heat required for operation of kWh/cow/day ~chillers (for milk) and heating of the digester *0.014 tons chilling per cow per day per hour of milking 

National Renewable Energy Laboratory 21 

Sources: Martin, John H. Jr. A Comparison of Dairy Cattle Manure Managem

Without Anaerobic Digestion and Biogas Utilization, EPA AgSTAR Program, 

EPA AgSTAR Handbook, Second Edition. 
Cost Values

Units Value 

cow f

Digester system installed $K = [563*(number of cows) + 1,170 cost 678,064]/103 Hydrogen sulfide removal % of total project capital cost 

($K) 

4.5* (6

Utility hookup % of total project capital cost 

($K) 

7.9 (11

MCFC uninstalled cost $/kW ($K), 300 kW system** 2,500 Federal tax incentive $K 324 CA SGIP using renewable CA SGIP using renewable $K $4 50/W for FC > 30kW 1 350 

fuel 

$K, $4.50/W for FC > 30kW 

using renewable fuel 

1,350 

*High end of cost range assumed for fuel cell purity requirements ** 250 kW system would be required for 6kWh/day/cow average production. Post-digestion solids % of total project capital cost 6.9 (98

separation system ($K) 

Hydrogen sulfide removal % of total project capital cost 4 5* (6

Sources: Martin, John H. Jr. A Comparison of Dairy Cattle Manure Managem

Without Anaerobic Digestion and Biogas Utilization, EPA AgSTAR Program, 

EPA AgSTAR Handbook, Second Edition. 

National Renewable Energy Laboratory 22 
Step 1

Title 

Click Process 1 Flow Diagram 

Title: Molten Carbonate Fuel Cell Case Study 

Authors: Darlene Steward, Mike Penev 

Process 

Flow 

Diagram 

Darlene Steward, Mike Penev 

Contact: Darlene Steward 

Contact phone: 303 275 3837 

Contact e-mail: darlene_steward@nrel.gov 

Organization: NREL 

Date: 1-Aug-09 

Web site: 

Simple: ju

Model users are first directed to this screen.
Step 2: Selecting Hardware

• Configure system 

• Click Input sheet 2 button INPUTS 

Heat sink 

SELECT ENERGY SUBSYSTEMS & RUN OPTIONS 

Water 

Fuel 

Fuel Burner 

Fuel cell system + PSA 

Grid 

Electrolyz

Sun PV 

Wind Turbines 

System Component Selection 

TRUE TRUE 

FALSE 

Peak Burner Fuel Cell System Electrolyzer 

Input Sheet 

• The Fuel 

Cell 

System analysis is active by de

• Burner evaluation should also be selected 
Step 3: Entering Detailed Specific

• The “Input_Sheet_Temsheet is the main modesheet is the main modeinterface • The subsequent slide

The subsequent slide

describe each section interface 

• Tools and defaults are available for most valu• A lot of customization possible for special caevaluations 
Step 3A: Entering Specificatio

Molten Carbonate Fuel Cell Power Model v1.0 

Molten carbonate fuel cell combined heat, hydrogen, and power installation for a large hotel in Los Angeles View Description 

Table of Contents 

View and edit project information Project Info Use default values 

Use Defa

Value

Cell color coding key Import and export data and perform analyses 

Run hourly energy calculations and 

calculate cost 

Key Toolk

Run Hou

Energ

Profil

Technical Operating Parameters and Specifications Financial Input Values Capital Costs Fixed Operating Costs 

Calculate energy cost with existing hourly 

energy profile 

Calcula

Cost 

Variable Operating Costs - Energy Feedstocks, Utilities, and Byproducts Variable Operating Costs - Other Materials and Byproducts Variable Operating Costs - Other Variable Operating Costs 

Technical Operating Parameters and Specifications 

Building type large hotel ca los angel 

Notes 

To import load profiles for a new location, click th

Building type large_hotel_ca_los_angel 

es 

Building location LOS_ANGELES,CA Total yearly electricity load (kWh/year) 2,006,040 Total yearly heat load (kWh/year) 2,104,728 Total yearly hydrogen demand (kg/year) 31,025 

To import load profiles for a new location, click th

for importing new load profiles 

• First input is specifying electricity and heat demands. • Estimates call for 1 kWh /cow-day = 42 kW for heat and e
Step 3B: Input Electric and Heat D

AC Demand Heat 

benchmark_lar

ge_hotel_ca_l

os_angeles.cs

v

benchmark_lar

ge_hotel_ca_l

os_angeles.cs

v 

(hourly electric demand) (hourly 

42.0 42 0. 

42.0 42.0 Year 2008 

42.0 Jan 1, day of week Tuesday 42.0 Demand maximum (kW) 42.0 42.0 Demand minimum (kW) 42.0 42.0 Demand average (kW) 42.0 

42.0 Demand Stdev (kW) 0.0 42.0 Demand total (kWh/year) 367920 42.0 42.0 42.0 42.0 42.0 42.0 

42 0. 42.0 42.0 42.0 42.0 42.0 42.0 42.0 42.0 

42.0 42.0 42.0 42.0 42.0 42.0 42.0 42 0. 42.0 42.0 42.0 42.0 42.0 42.0 42 0. 42.0 42.0 42.0 42.0 42.0 42.0 42.0 42.0 

DemDemDem

Dem

D Dem

• Input 42 kW for each hour for both the electricity and hea• Go back to the Input_Sheet_Template sheet 
t

Step 3C: Economic criteria specif

Financial I lnput Values 

Reference year 2005

2010

1

100%

0%

0%

0.038

2020

100%

100%

40%

50%

10%

10%

1.9%

10.0%

6.0%

35.0%

38.90%

15%

Default

Assumed startup year Length of construction period (years) % of capital spent in 1st year of construction % of capital spent in 2nd year of construction % of capital spent in 3rd year of construction % of capital spent in 4th year of construction Startup time (years) Plant life (years) Default Analysis period (years) Default % equity financing (%) Default Interest rate on debt, if applicable (%)Debt period (years)% of fixed operating costs during startup (%)% of revenues during startup (%)% of variable operating costs during startup (%)Decommissioning costs (% of initial capital investment) Default Salvage value (% of initial capital investment) Default Inflation rate (%) Default After-tax real IRR (%) Default State taxes (%) Default Federal taxes (%) Default Total tax rate (%)Working capital (% of yearly change in operating costs) Default 

• Verify and update economic assumptions
_

Step 3D: Capital Costs 

Direct Capital Cost Specification ( “Inp_ p ut Sheet_Template” tab) 

Direct capital costs (enter costs on equipment sheet) 

High-temperature fuel cell and/or reformer process direct capital cost ($) Electrolyzer direct capital cost ($) 

$2,339,362 Go to D

NoNo 

ttS 

Hydrogen fuel cell direct capital cost ($) NoNo 

ttS 

Auxiliary heater direct capital cost ($) $0 USolar (PV) direct capital cost ($) NoNo 

ttS 

Wind turbine(s) direct capital cost ($) NoNo 

ttS 

Hydrogen compression storage and dispensing direct capital cost ($) 

Total direct capital costs $2,339,362 

NoNo 

ttS 

• This section provides links to the fuel cell system and hydro
Step 3E: Remove Hydrogen Co-p

Hydrogen Demand (% of total daily deHydrogen Demand 

(“H2 Demand” tab) 

Enter zero for 

daily hydrogen demand 

0.0%0.0%0.0%0.0% Average daily hydrogen demand 0 kg/day

0.0% Hourly Hydrogen Demand Statistics (% of avg daily demand) 0.0% Maximum 50.00% 

0.0% Minimum 0.00% 

50 0% . 

Average 4 1 % 4.17 

0.0% Standard deviation 13.82% 

0.0% Surge: % above the system average demand 0.0000 

0.0% Friday average above weekly average (%) 0.0000 0.0% Adjusted average daily demand 0 kg/day

0.0%0.0%0.0%

0 0%. 

50.0% 

0.0% 

• Remove all hydrogen demand by zeroing daily H2 deman

• Remove all capital cost for hydrogen dispensing 

Hydrogen St(“Hydrogen 

Enter zero for 

all hydrogen dispensing costs

Baseline 

Major Pieces/Systems of Equipment Co

Low-pg ressure storage tanks $ 

Cascade storage tanks $ 

Compressor cost $ Dispensers $ 

Electrical upgrades $ Control and safety equipment $ 

300 ft pipeline to filling station $ 

Totals $ 
Step 3F: Fuel Cell Capacity

Fuel Cell Specifications (“Fuel Cell S

ystem” tab) 

FUEL CELL SYSTEM SPECIFICATIONS Descriptions 

( y ) 

Maximum electricity output rating kW 300.0 AC average demand. Minimum electricity output rating kW 249.0 Efficiency of H2 production (kW H2 produced / kW CHP heat reduced) Efficiency of H2 production (kW H2 produced / kW CHP heat reduced) 96% Coefficient is derived from ma

Coefficient is derived from ma

Efficiency of H2 over-production (kW H2 produced / additional kW fuel consumed) 80% Coefficient is derived from maMaximum fraction of heat converteable to hydrogen 0.65 Coefficient is derived from ma

Maximum amount of hydrogen over-production as fraction of H2 production 0.50 Coefficient is derived from ma

• Maximum FC capacity of 300 is a good fit with available digester gas • 83% of 300 kW allows for utilization factor specification = 249 kW of • Remainin

gcoefficients are not im

portant for this anal

ysis as the

y ar
Step 3G: Inputting System Co

Fuel Cell Cost Specifications (“Fuel Cell S

ystem” tab) 

INVESTMENT (Inputs REQUIRED in Major Pieces/Systems of Equipment 

Fuel cell CHP equipment uninstalled cost Fuel cell CHP equipment uninstalled cost 

Plug Flow Digester System Digester, engineering, and installation Total ancillary systems 

Post-digestion solids separation system Hydrogen sulfide treatment 

Utility hookup Utility hookup 

Totals 

Baseline 

Uninstalled 

Costs

$ 750 000 750,000

$ 1,166,477 

$

 247,435 

$ 97,560 

$ 63,626 

$ 111,699$

 2,436,796 

Installation Cost Ba

Factor Install

1 20 . 

$ 

0.00 $ 

1.00 $ 1

$ 

1.00 $ 

1.00 $ 

1.00 

$ 

$ $ 

$

 -

$

 2,33

• This sheet would contain all hardware capital costs This sheet would contain all hardware capital costs • If installed costs are used, enter installation cost factors o
_

$ 

Step 3H: Input Indirect Capital Co

Indirect Capital Costs Specification (“Inp_ ut Sheet_Template” tab) 

Indirect depreciable capital costs 

Site preparation ($) Engineering & design ($) Engineering & design ($) Process contingency ($)Project contingency ($)Other (depreciable) capital ($)One-time licensing( fees ($)Up-front permitting costs ($) 

Total indirect capital costs Total Direct & Indirect Capital Investment 

$2

$1$1

$1

$

$5

$2,9

The power model provides default values for each valuThe power model provides default values for each valu

but it can be overridden 
Step 3I: Incentives Specificati

Incentives Specification (“Input_Sheet_Template” tab) 

Incentives and credits (enter as positive numbers) 

Federal business energy tax credit - fuel cells ($) Federal alternative fuel infrastructure tax credit ($) Federal combined heat and power tax credit ($) Federal business energy tax credit - solar ($) Federal business energytax credit - wind ($)Other one-time tax incentive credits ($) 

Total incentives and credits 

$324,000 

$0 

CalCal

CalcCalc

C l a c

$1,350,000 Enter as a p

number. 

$1,674,000 

• Federal tax incentive is 30% of capital or 3 000 $/kW which

Federal tax incentive is 30% of capital or 

3,000 $/kW, which

• Self Generation Incentive Program (SGIP), is a CA program 4,500 $/kW of installed capacity of renewable electric produc
Step 3J: Specifying Fixed Operati

Fixed Operating Costs Specifications(“Input_Sheet_Template” tab)

Fixed Operating Costs 

Production facility plant staff (number of FTEs)Burdened labor cost, including overhead ($/man-hr)Production facility labor cost, $/yearStorage/dispensing labor required (hours/year)Storage/dispensing labor cost ($/man-hr)Storage/dispensing labor cost ($/year)G&A rate (% of labor cost)

$0 

0.0 

$0.00 

$0 

20% 

$0 

$2,339 

2% 

$25,004 

$0 

$46,787 

$0 

$0.00 

$74,131 

Default 

G&A ($/year)Licensing, permits, and fees ($/year)Property tax and insurance rate (% of total capital investment) Default Property taxes and insurance ($/year)Rent ($/year)Material costs for maintenance and repairs ($/year)Production maintenance and repairs ($/year)Forecourt maintenance and repairs ($/year)Other fees ($/year)Other fixed O&M costs ($/year)

Total fixed operating costs 

• Note that some costs for hydrogen production would not a

Note that some costs for hydrogen production would not a

• For this analysis we assumed that the fuel cell is installed leasing is not needed. 
$

Step 3K: Feedstock Cost Specific

Commercial Natural Gas 

No 

$10.150 

Commercial → Electricity metric Electricity_metric 

Look up base prices for each year? No Enter base electricity price ($(2005)/kWh) 0.124 

Byproduct electricity pricing 

Select price type Enter base electricity price ($(2005)/kWh) 

Energy Feedstocks, Utilities, and Byproducts Select the price table to use 

AEO 2005 High A Case 

Reforming fuel cell fuel specification 

Look up prices for each year? Enter fuel price ($(2005)/MMBtu) 

Commercial Natural Gas_metric →

Fuel price ($(2005)/kWh) 

Auxiliary heater (peak burner) fuel specification

Look up prices for each year? 

Commercial Natural Gas_metric →

Enter fuel price ($(2005)/MMBtu) 

Edit grid electricity import price matrix Grid electricity base prices 

Commercial Electricity_metric →

Edit 

Feedstock Costs (“Input_Sheet_Temp

Commercial Natural Gas 

No 

$0.000 $0.000 

Time of Day 

0.124 

• Water costs can be specified as well, but they are typically • Note: Detailed grid cost structure can be accommodated b
t

Step 3L: Verify Other Variable Operati

Other Variable Operating Costs 

Other variable operating costs (e.g., environmental surcharges) ($/year) $0 Other material costs ($/year) $0 Grid peak charges ($/year) Grid peak charges ($/year) $0 Waste treatment costs ($/year) Solid waste disposal costs ($/year) Total unplanned replacement capital cost factor (% of total direct d i bl / ) 

1.50% 

depreciable costs/year) Royalties ($/year) $0.00 Operator profit ($/year) $0.00 Subsidies and tax incentives based on production ($/year) $0.00 Refueling station O&M costs ($/year) 

Total variable operating costs excluding fuel ($/year) 

$172 

• Note that this is the place to define maintenance costs (1.5default) • Detailed capital cost replacements can be specified within “Replacement Costs” sheet • At this point, the model specifications are complete! 
Step 4: Running and Results

“Input_Sheet_Template” tab:

Table of Contents 

View and edit project information f 

Cell color coding key 

Use default values 

Import and export data and perform 

analyses 

Run hourly energy calculations and Ru

Technical Operating Parameters and Specifications Financial Input Values Capital Costs 

Calculate energy cost with existing hourly 

energy profile 

calculate cost 

Project Info 

Us

V

Key T

E

C

Capital Costs 

Once all inputs 

are complete, click here 

• Running the model performs an hourly energy analysis • After energy analysis is complete, economic analysis and evaluated • Completed running will place you on the results tab 
Reviewing Results
t

Analysis Results for 1,000 Cow D

1,000 cow dairy Electricity (kWh/y) Heat (kWU d i Used onsite 367 920 367,920 367 920 367,920 Sold 1,810,190 T t l Tota 2 178 110 2,178,110 367 920 367,920 

Overall system efficiency is 54% based on he

Utilization of available heat is only 26%. 

National Renewable Energy Laboratory 40 
Analysis Results for 1,000 Cow D

Baseline system energy costs (without to installation of fuel cell) 

Electricity ($/year) 

Usage and Demand charges $ 

55,461 

Commercial Natural Gas ($/year)

 $ 

14,157 

Hydrogen (supplied by forecourt SMR system) system) 

$ 

-

H

ydro

gen price = $0/kg 

Total baseline system energy cost per year $ 

69,618 

Cost of na

for chillers 

$14,157/y

CHHP System Annualized Costs CHHP System Annualized Costs F 

F

Annualized costs co

Capital costs $92,806 Decommissionin

g costs $1,176 a

Fixed O&M Fixed O&M $14,422 $14,422 w

w

Feedstock costs $0 inOther raw material costs $0 B

yproduct credits -$43,590 re

Other variable costs $8 Supplementar

y electricity 

$2,702 

Supplementar

y heat $0 

Total $67,525 

National Renewable Energy Laboratory 41 
GHG Emissions Comparison

GHG Emissions Comparison 

100,000.00 

~515

would 

diges

50,000.00 

ester CH4 

diges

vente

-50,000.00 

0.00 

Base Case (w/o digester) g 

CO2eq/mmBtu 

Digester with Fuel Cell (g 

CO2eq/mmBtu) 

mmBtu Dige 

-100,000.00 

, 

g CO2eq/m 

-150,000.00 

GHG Emissions from manure management GHG Emissions from biogas recovery 

GHG Emissions from bio

gas processin

g avoided emissions - electricity generation 

avoided emissions - heat utilization

Data Source: CARB, Detailed California-Modified GREET Pathway for Liquefied Natural 

Digester BioGas, CARB Stationary Source Division, Version 2.0, September 23, 2009. 

National Renewable Energy Laboratory 42 
Thank You 

Contact Information Contact Information: 

Darlene.steward@nrel.govMichael.penev@nrel.gov 

National Renewable Energy Laboratory 43