aps

Arizona Public Service Company

F I UR CORNERS S EAM ELECTRIC STATION

‘.I.Box355.FRUITLAND,NEWMEXI 0 8 416

November 25, 2014

CERTIFIED MAIL

Lisa Beckham

Environmental Engineer

Air Division, Permits Office (Air-3)

EPA Region 9

75 Hawthorne Street

San Francisco, CA 94105

RE: Four Corners Power Plant SCR Retrofit Project — Addendum to Application for PSD

Permit

Dear Ms. Beckham:

Arizona Public Service Company (APS) is submitting an addendum to the revised application for the

Prevention of Significant Deterioration (PSD) permit for the Four Corners Power Plant (FCPP) SCR

Retrofit Project resubmitted on April 29, 2014 and amended on July 2, 2014. This addendum

addresses the following items: (1) maximum heat input rate, (2) parasitic load for sorbent injection

system, and (3) projected hours of operation at reduced load.

1. Maximum heat input rate — 7411 MMBtuIhr as maximum heat input rate for

determining projected future actual emissions

In the permit application submitted on April 29, 2014, APS determined the projected future

actual emissions for Units 4 and 5 by using a maximum heat input rate of 7411 MMBtuIhr to

estimate an annual heat input of 116,008,264 MMBtu/yr. Below is the calculation:

7411 MMBtuIhr * (2 units) * 8760 hours/yr * 89.35% (Capacity Factor) = 116,008,264

MMBtuJyr.

The calculated projected future actual annual heat input was then used to calculate emission

increase and parasitic load in tables A-3 and A-9 of the permit application.

APS used the 7411 MMBtu/hr values because it represented the 99.25 percentile of hours of

operation for units 4 and 5 over the 2009-2011 timeframe. Table 1 below is based on Clean

Air Markets Division (CAMD) data and shows the average heat input for Units 4 and 5 vs.

percentile.
Ms. Lisa Beckham

EPA Region 9

November 23, 2014

Table 1. Average Heat Input Percentiles

Average Heat Input

(MMBtu/hr) for

Units4and5

7,517 99.900%

7,478 99.800%

7,433 •99.500%

99.250%

7,392 99.000%

7,344 98.000%

Furthermore, 7411 MMBtuJhr was used in previous analyses in both the Four Corners

Regional Haze Supplemental Best Available Retrofit Technology (BART) analysis1 and the

Four Corners Power Plant and Navajo Mine Energy Project Draft Environmental Impact

Statement, Volume 1 •2

APS also used a conservative capacity factor of 89.35% based on the RTSIM cost production

model. The projected future capacity factors are determined by including the following

information in the RTSIM cost production model:

• Weather Normalized Forecasted Loads provided by Revenue Analysis and Forecasting.

• Unit Parameters and Outage schedule provided by Fossil Generation.

• Long Range Resource Plan provided by Resource Planning and Analysis.

Forecasted gas and coal fuel prices provided by Fossil Fuel Procurement.

• Forecasted nuclear prices provided by Nuclear Engineering.

• Forecasted renewable profiles from Renewable Energy.

• Forecasted gas and electric market prices provided by Resource Management.

The model will determine the most cost efficient means of supplying energy to meet the

forecasted load, given the available resources, in consideration of both outage limitations

and market conditions.

On the most simplified level, the model determines the most cost efficient utilization of

resources by unit and market heat rates. Where unit heat rate is the ratio of Input Energy

EPA uses the 7411 MMBtu/hr value in Table 1 of the “Supplemental Notice of Source Specific Federal

Implementation Plan for Implementing Best Available Retrofit Technology for Four Corners Power Plant:

Navajo Nation,” available at http://www.regulations. gov/#!documentDetail ;D=EPA-R09-OAR-20 10-0683-

0096.

2 Four Corners Power Plant and Navajo Mine Energy Project Draft Environmental Impact Statement

Volume 1_can be located in the OSMRE Western Region document library at:

http://www. wrcc.osmre.go v/Current Initiatives/FCNAVPRJIFCPPEIS.shtm.

The 7,411 MMBtu heat input is mentioned in the following places:

- Footnote to table ES-I pg. iii in the Executive Summary

- Footnote to table 2-8 on pg. 2-38

- Footnote on pg. 4.1-37

2

Percentile

7,411
Ms. Lisa Beckham

EPA Region 9

November 23, 2014

(MMBTU) to Output Power (MWh) and market heat rate is the ratio of Electric Prices

($fMWh) to Gas price ($IMMBTU). Available units and transactions are then stacked from

lowest heat rate to highest according to minimum (block sizes) and maximum

(capacity/transaction) limits until forecasted load levels are met for each hour.

On a more complex level the model takes into account the proportional nonlinear variability of

unit and market heat rate with respect to energy generated or transacted. The model further

takes into account various limiting factors on the units and market such as: Planned and

Forced Outages, Unit Operating Constraints, Transmission Constraints, Transaction Limits,

Market Liquidity, as well as Reliability and Reserve Requirements.

As detailed in Table 2 below, Four Corners Units 4 and 5 have achieved capacity factors

greater than 89.35% in the past:

Table 2. Historical Capacity Factors

Unit4 Unit5

2000 74. 86% 89. 72%

2001 87.61% 81.70%

2002 86.83% 57.41%

2003 90.53% 86.59%

2004 68.29% 93.31%

2005 87.82% 82.03%

2006 90.08% 88.64%

2007 79.95% 75.51%

2008 90.27% 64.74%

2009 85.18% 84.58%

2010 57.09% 86.58%

2011 76.97% 74. 14%

2012 74.57% 75.99%

2013 68.34% 64. 10%

2. Parasitic load for sorbent injection system — Estimate of parasitic load for operation of

sorbent injection system

APS estimates that the parasitic load due to the operation of the sorbent injection system will

be approximately 108 KW. APS estimated the auxiliary power needed for injecting hydrated

lime, Sodium Carbonate (SBS) or Trona. However, APS does not plan on using a sodium

based sorbent as explained in Section 4 (Control Technology Review) of the permit

application. Attachment B shows the calculation spreadsheet using the Breen Model to

estimate the feed rates. Table 3 show how the parasitic loads were calculated using the feed

rates estimates from the Breen Model.
Ms. Lisa Beckham

EPA Region 9

November 23, 2014

Table 3. Parasitic Load Calculation for Sorbent Injection

Aux Power (%) = Feecirate (T/hr) x 18/ Unit Size (Gross MW)

UnitSize 8lOGrossMW

Lime Feedrate 0.6013 T/hr

SBS (Sodium Carbonate) Feedrate 0.8613 T/hr

Trona Feedrate 1.6587 T/hr

Lime Aux Power 0.0134 %

SBS Aux Power 0.019 1 %

Trona Aux Power 0.0369 %

Lime Aux Power 108 KW

SBS Aux Power 155 KW

Trona Aux Power 299 KW

The parasitic load for SCR was estimated at 0.142%, and for the economizer bypass it was

estimated at 0.147%. The sum of the two is 0.289%; however, APS assumed 0.3% to be

conservative. Adding the auxiliary load due to the sorbent injection will change the overall

parasitic load from 0.289% to 0.303%.

3. Projected hours of operation at reduced load — Justification for assumptions made in

determining projected hours of operation at reduced load for Units 4 and 5

APS estimated the increased fuel use due to parasitic load of operating the SCR and the

economizer bypass by estimating the hours of operation at reduced load. APS used the

projected hourly data created by the RTSIM cost production model and assumed all operating

hours less than 90% load were at reduced load.

The selection of 90% of full load as a cut-off for low load operation was set based on the

assumption that the APS Marketing Department would not de-rate the units if they were

operating at or above this level. However, when running at full capacity the load still

fluctuates based on several factors.

- Weather (temperature, pressure, and humidity) will affect the output of a boiler.

- Equipment problems and equipment out of service could force a unit to reduce load.

- Maintenance work on a piece of equipment could force a load reduction.

- Where the unit is at in an outage cycle is another factor. Everything runs best

immediately after an outage and slowly degrades until the next outage.

- Fouling, leaks, and pluggage can be a hindrance to running at full load.

Also, the effect of reactive load on MW output is something that could make it appear that a

unit is running at more or less than full load when it is actually running at full load. This is the

cause for some of the instances when a unit appeared to be running higher than it was capable

of. At the same actual total real power production (MVA) and heat input (MMBTU), it is

possible to get different useful power production (MW) depending on the reactive load

(MVAR). In other words, at the same fuel burn and actual turbine output, different MW’s can

4
Ms. Lisa Beckham

EPA Region 9

November 23, 2014

be reported. Usually the difference is less than 2 MW, but it can be as high as 15 MW. That

is one reason a nominal full load MW can produce different numbers over the course of a

year, but still actually be full load. It varies due to factors outside the unit. The type of load

that the grid is putting on the unit affects how much of the produced power appears as useful

MW’s. For instance, compact fluorescent lights (CFL’s) can pull significantly more true

power than they would indicate. The measured MW’ s from the unit would be much lower

than the actual power produced in MVA because of the reactive MVAR required to run the

CFL’ s.

In support of this addendum, a signed Certification of Truth, Accuracy and Completeness is included

in Attachment A.

We respectfully request that EPA review this addendum in a timely manner and move forward with

processing the PSD permit application, If you have any questions regarding this submittal, please

contact Mark Hajduk at 602-250-3394 or at mark.hajduk@aps.com.

Sincerely,

Thomas H Livingston

Responsible Official

Four Corners Steam Electric Station

Enclosures: Certification of Truth, Accuracy, and Completeness

Sorbent Injection Feed-Rate Calculation Spreadsheet

cc:

Distribution List With Attachment

EPA Region 9 Gerardo Rios, Chief, Permits Office (AIR 3)

EPA Region 9 Ann Lyons

Navajo Nation EPA Raju Bisht X
Attachment A

U.S. ENVIRONMENTAL PROTECTION AGENCY

APPLICATION FOR FEDERAL PSD PERMIT

APPLICATION FORM CTAC - CERTIFICATION OF TRUTH, ACCURACY, AND

COMPLETENESS BY RESPONSIBLE OFFICIAL

INSTRUCTIONS:

One copy of this form must be completed, signed, and sent with each submission of

documents (i.e., application forms, including any updates to applications), and for

every document required by a part 71 permit (e.g., annual compliance certification,

6-month monitoring reports, progress reports, and notices required by the terms of a

part 71 permit).

Responsible Official. Identify the responsible official and provide contact

information.

Name: (Last) Livingston (First) Thomas (Middle) H

Title: Plant Manager

Street or Post Office Box: P.O. Box 355

City: Fruitland State: NM Zip: 874 16-0355

Telephone: (505) 598-8200 Ext.: Facsimile: (505) 598-8339

Certification of Truth, Accuracy and Completeness. The Responsible Official

must sign this statement.

I certify under penalty of law that, based on information and belief formed after

reasonable inquiry, the statements and information contained in these documents are

true, accurate and .

Name (s

Name ,Z5 ./ (printed or typed): Thomas H. Livingston Date:
Attachment B

Breen Model Dry Sorbent Injection Calculation Spreadsheet
Mass of Sosbent Required Muss of Acid • 406 • (MW-loWest/MW-Acid) • Mole Factor

Mete Facter-102 Mete Faeter-SOV Mete Fatter-lId5 Mole Faeter-HP

8864

MWeflO3

MW sf102MWofTrsoa 226 6.6666667 0.666666667 0.131133131 (1033131133MWoINa2CO3 166 1 1.66 0.6 (1MWefNeHCO3 66 2 1 1 0.MWeICa)OH(2 74 1 0.5 0.MW of Iht(OH)Z 50.3 1 0.5 0. ____________________________ MWefbbO 40.3 1 0.5 0.

MWoFHCL 16.5

MWoIHF 26HCL 4 thu/HrHF 155/H

502 1.78 MStu

Lead 70 MWetts ,_—

Heat Input MMRto/H~_.—

502 6.70,jyoo/f{C502.503 Conversion tote 162% 8188W DiRer503 271, Lbs/Hr deefred FiRS CF = 90%

H2504 IlL LbNIB ~0osbesttor503 lesbentferHCt SosbentforHP Total-AllAsids

Snrbent-Trona )lb/hr) r 2.401. 438.02 4774 3,11732 $202/T 52,643.529Sorbest-Na2COI (lb/kr) r 1,078. 366.1 3359 1,72267 $0Sorbent- NaHCOI (lb/kr) ‘ 6837 4t8.4 266.2 1,438.39 Resisbat $190/f $1,077,128Serbeet-Ca)0H)2 (lb/br) r 7529 21513 234 1,20262 $185/f $677,034Serbent-Mg)OH)2 (lb/kr) r 988 1694 194.7 1,342.95 50Surbent-MoO (lb/br) .‘‘ 8201 117 16 1277 1,665. $0

Mule Factor= tot Moles of Sorbent per Mole of Add. For t.0. you need 2 Moles of Truna for every 3 Moles sf103

Sodium Reautlons

2)Na2CO3.NaHCO3.2H20) -v 3Na2C03 + C02v5 920 )Trssa fIrst ralnees 10 sodium Carbonate)

Na2CO3+503-c Na2204+C02N07CO9v7HCI-c 2NsCl+H2OcCO2

Na2CO3+2HF-v 2NaF+H2OvCO2 -___________________

Calsium Roactios

Ca)OH)2+S03+H20 0 Ca504v2H20Ca)OH)2 v2HCI-v CaCi2v 2 H20Ca)OH)2v2HF 0 CaF2+2H20Magneslure Reactions

Me)OH)2vS03 v H20 -v tsIgSO4 +2 H20Me)OH)2 v2HCI -c MgCI2 +2 H20MalflHl2 v2HP -v MeP2+ 2920Maeoesla ReactionsMeO+503+920-v Mt504+ 420

MgO+2HCI-v MeCl2v 420

MgOv2HF-v MgF2+ H20

calastat 8~aad 802 PPM

02 3%

Load 770 MW

503 Conversion Rate 1.62%

Calujiote:502 0Dm: — ,klsCfl+ ‘ic.,.i u,-r.-.,1svmv Cnnversinn Psctor )t6SO2ppm: tfl84 ppm$02 ppmi 30.13 ppm

fiat Fader

Fuel Type rd )dscf/MMbtcf H88)Rts)

anthrante 10,166 12,300(16

Coal bltuminoos 9,788 11,~itb

tienlte 9,860 Z200/lb

. residual 9,198 ‘50,~/ge’ Oil distillate 9,130 140,000/gal

Gas natural 8,710 3.010/sd

Wood 9,240/tb 1~200(lbWood Barb 9,666/lb 4,50~tb

srnamcssul.as.st.uss6orsrasdanres

O B CE ma. sa-tiianjlnst f’S IN. srrcraruasyaaa,oteejcaderr

StWit Star Caat

Prs~

649am

502

Coal-RIO/Lb 8776 Rtu/LbCoat-S 078%502-Lb/MMBTU Lb/MMBto102- ppm

Coal-Ct 0 0240%

KCL-Lla/MMBTU Lb/MMRIsHCI - ppm 28.32407846 ppm

Coal-F 00140%

CF-Lb/MMBTIJ Lb/MM6tu

Coal Anti 2283%Ash Lb/mmBTU% PlyAsh 75%

vlyasho/mm6TU 1948495890

1.78 Lb/MMRIu Lb/

Heat Bale

Heat InputFoci Factor )Sit-Coat)

502 Conversion Factor

980 MM8tu/IIW-Hr7546 MM8tu/tr9788 dscf/MM8tu

167t-07 Lb/sct/)ppm 102)