# 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

7,411Ms. 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
4Ms. 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 

# ,Z5 ./ 

### Name (printed or typed): Thomas H. Livingston Date:AttachmentBBreenModelDrySorbentInjectionCalculationSpreadsheetMassofSosbentRequiredMussofAcid•406•(MW-loWest/MW-Acid)•MoleFactorMeteFacter-102MeteFaeter-SOVMeteFatter-lId5MoleFaeter-HP8864MWeflO3MWsf102MWofTrsoa2266.66666670.6666666670.131133131(1033131133MWoINa2CO316611.660.6(1MWefNeHCO3662110.MWeICa)OH(27410.50.MWofIht(OH)Z50.310.50.____________________________MWefbbO40.310.50.MWoFHCL16.5MWoIHF26HCL4thu/HrHF155/H5021.78MStuLead70MWetts,_—HeatInputMMRto/H~_.—5026.70,jyoo/f{C502.503Conversiontote162%8188WDiRer503271,Lbs/HrdeefredFiRSCF=90%H2504IlLLbNIB~0osbesttor503lesbentferHCtSosbentforHPTotal-AllAsidsSnrbent-Trona)lb/hr)r2.401.438.0247743,11732$202/T52,643.529Sorbest-Na2COI(lb/kr)r1,078.366.133591,72267$0Sorbent-NaHCOI(lb/kr)‘68374t8.4266.21,438.39Resisbat$190/f$1,077,128Serbeet-Ca)0H)2(lb/br)r7529215132341,20262$185/f$677,034Serbent-Mg)OH)2(lb/kr)r9881694194.71,342.9550Surbent-MoO(lb/br).‘‘82011171612771,665.$0MuleFactor=totMolesofSorbentperMoleofAdd.Fort.0.youneed2MolesofTrunaforevery3Molessf103SodiumReautlons2)Na2CO3.NaHCO3.2H20)-v3Na2C03+C02v5920)TrssafIrstralnees10sodiumCarbonate)Na2CO3+503-cNa2204+C02N07CO9v7HCI-c2NsCl+H2OcCO2Na2CO3+2HF-v2NaF+H2OvCO2-___________________CalsiumRoactiosCa)OH)2+S03+H200Ca504v2H20Ca)OH)2v2HCI-vCaCi2v2H20Ca)OH)2v2HF0CaF2+2H20MagneslureReactionsMe)OH)2vS03vH20-vtsIgSO4+2H20Me)OH)2v2HCI-cMgCI2+2H20MalflHl2v2HP-vMeP2+2920MaeoeslaReactionsMeO+503+920-vMt504+420MgO+2HCI-vMeCl2v420MgOv2HF-vMgF2+H20calastat8~aad802PPM023%Load770MW503ConversionRate1.62%Calujiote:5020Dm:—,klsCfl+‘ic.,.iu,-r.-.,1svmvCnnversinnPsctor)t660•10-7lb/sd/ppm102)•HI)MMRtu/Hr))•))20.9-%02)/20.9)SO2ppm:tfl84ppm$02ppmi30.13ppmfiatFaderFuelTyperd)dscf/MMbtcfH88)Rts)anthrante10,16612,300(16Coalbltuminoos9,78811,~itbtienlte9,860Z200/lb.residual9,198‘50,~/ge’Oildistillate9,130140,000/galGasnatural8,7103.010/sdWood9,240/tb1~200(lbWoodBarb9,666/lb4,50~tbsrnamcssul.as.st.uss6orsrasdanresOBCEma.sa-tiianjlnstf’SIN.srrcraruasyaaa,oteejcaderrStWitStarCaatPrs~649am502Coal-RIO/Lb8776Rtu/LbCoat-S078%502-Lb/MMBTULb/MMBto102-ppmCoal-Ct00240%KCL-Lla/MMBTULb/MMRIsHCI-ppm28.32407846ppmCoal-F00140%CF-Lb/MMBTIJLb/MM6tuCoalAnti2283%AshLb/mmBTU%PlyAsh75%vlyasho/mm6TU19484958901.78Lb/MMRIuLb/MMBtsCalsaalatedtmmlolPPMHeatBaleHeatInputFociFactor)Sit-Coat)502ConversionFactor980MM8tu/IIW-Hr7546MM8tu/tr9788dscf/MM8tu167t-07Lb/sct/)ppm102)