# nationalgrid

September27, 20I0

Mr. Scott Griffin 

### Environmental Engineer 1 NYSDEC Division ofAir Resources Bureau ofAir Quality Planning 625 Broadway, 2"" Floor Albany, New York 12233-3251 HJt:r'VI!O
;01 (1

# J\!~**QU:~~P1'ANNING**

RE: National Grid's Compliance Demonstration for NYSOEC BART 

### Regulations, 6NYCRR Part 249

Dear Mr. Griffin,


### National Grid owns and operates five steam electric generatingunits which arc subject to Part 249 BART Regulations. These units includeNorthport Units 1,2,3 and 4 (385Mw each, primarily natural gas fired, with backup oil firing capability) and E. F. BarrettUnit 2 (185 Mw, natural gas fired, with 

### oil backup for use 

### in the event ofa natural gas shortage).

National Grid's BART Compliance Demonstration incorporates the guidelines presented by theNYSDEC on March 3, 2010 at theirAlbany office and guidance obtained from subsequent technical discussions 

### with NYSDEC. We have perfonned a 

### construction and economic evaluation, 

### in order

### to detennine which control technologies
are within the BART Control threshold of$5500/ton. As shown in the attached analysis, Selective Catalytic Reduction (SCR) significantly exceeds this threshold for NOx control at the four identical Northport Units as well as Barrett Unit 2. Separated OverFire Air (SOFA) (analysis not shown) was selected as the BART control technology, since its control costperton ofNOx is below the $5500 threshold. SOFA technology is recognized by EPA as the most advanced, state ofthe art 

### combustion control technology forNOx. National Grid will have SOFA installed on its five, BART affected steam units by the end of2013, in compliance with NYSDEC's January 

### 1.2014 required compliance date. Presumptive NOx Limits with SOPA

The lowest NOx emission rates which can be achieved during non-steady state operating conditions (load following) at the four Northport Units and Barrett Unit 2, with SOFA technology is 

### 0.201b/mmBtu on oil and O.IOlb/mmBtu on gas. We will comply with these limits on a

### 24 hour average basis (midnight to midnight) beginningJanuary 

### 1.

175East Old Coultry Road. Hicks\IiIe. NY 1 1801. www.nationalgrid.com

# nationalgrid

Mr. Scott Griffin September 27, 2010 PageTwo

2014, as required by the BART Regulations. The oil emission limit will he asswned during any 24hour averaging period, whenoil is fired.



### . As providedin Part 249, NOx limits will be developed for startup and shutdown periods (approximately 20/year/unit anticipated). This is required since SOFA technology is a combustion control, which becomes 

### fully effective above minimum load. Following the installation ofSOFA, we will collect start up and shut down NOx emission data and review with NYSDEC staffin order to develop appropriate startup and shutdown limits.

. Presumptive S02 Limits (fuel sulfur limits)



### National Grid will 

### comply with 

### NYSDEC BART requirements for S02 emissions by limiting the fuel sulfur content atNorthport Units I, 2, 3 and 4 to 0.7% (30% below the 6 NYCRR Part 225-1 limit of1.0%). The fuel sulfurcontent at Barrett Unit 2 will be limited to 0.37%. These fuel sulfur values comply with the I% fuel sulfur limit in the BART Regulations.

BART Compliance Dcmonstration for Particulate Mattcr

For the particulatematter, an analysis combination offactors, including cost and feasibility ofadditional control technologies, have been considercd. All four units at Northport have electrostatic precipitators (ESP's). There is no feasible or cost effective particulate control technology available, beyond ESP's for a natural gas fired unit utilizing low sulfur oil as a backup fuel. E. F. BarrettUnit 2 is a natural gas fired unit with low sulfur (0.37%) oil used as a backup in the event ofgas shortages. Due to the verylow particulate emissions for this unit, the cost ofinstallation and opcration for an ESP is well in excess ofNYSDEC's $5500 cost per ton criteria for BART as shown in the attached economic analysis.

The attached analysis, along with the supporting technical infonnation forwarded to your officeon June 15, June 18 and August 27, 2010, illustrates that even with conservative construc;:tion cost estimates and the assumption offull load operation for 100% ofthe time, SCR's for NOx control are well above the 

### $5500/ton BART threshold atNorthport Units I, 2, 3 and 4 (identical) and BarrettUnit 2. The cost ofan Electrostatic Precipitator forparticulate control at Barrett Unit 2 is also well above the 

### $5500/ton BART threshold.

# nationalgrid

Mr. ScottGriffin September27,2010 

### Page Three

Ifyou 

### haveany questions regardingthis analysis orfurtherquestions regarding the supportingmaterial previouslyforwarded to your office at yourrequest, please contact eitherGeorge Martin (516) 545-2575 orCathy Waxman (516) 545-2579.

Yours truly,

Christopher Corrado Director, Environmental Management. NY South

Attachment

cc: Robert Sliwinski (NYSDEC

- Albany) Melange Genece (NYSDEC RAPCE

- Region I) Humberto Roman (NYSDEC

- Region 1) Mike Jennings (NYSDEC

- Albany)Facility Name

Facility 10 Emission Point Control Type

Fixed O&M Variable O&M Annual Operating Costs 1 Capital* 2 Calculate Capital Recovery Factor 1= Annual interest rate n= Equipment or replacement parts life in years (n=1 0) 3 Calculate Annual Equipment Cost (Multiply Item 1 by Item 2 4 Annual Operating Costs 5 Total Annual Costs (Add items 3 and 4[A to e]) 6 Calculate Annual Tonnage Reduction 6A Projected NOx tons maximum annual emissions (2014-2023) 6B Percent capture and control achieved beyond SOFA levels 6C Annual tons NOx reduced (multiply item 6A by 68) Total Cost of Controls per Ton Reduced (Divide Item 5 by Item 6C) Annual NOx tons assuming operation at full load 100% of time Percent capture and control achieved beyond SOFA levels Annual tons NOx reduced Total cost of controls per ton reduced Northport E.F.8arrett IE.F.Barrell

Units 1,2,3,4 385Mweach Unit2 185 mw Unit 2 (185mw SCR SCR IESP $580,000 $266,800 $196,000 $1,170,000 $538,200 $327,000 $1,750,000 $805,000 $523,000 $70,000,000 $30,000,000 $17,000,000 0.13 0.13 0.13

5% 5% 5%

10 10 10 $9,100,000 $3,900,000 $2,210,000 $1,750,000 $805,000 $523,000 $10,850,000 $4,705,000 $2,733,000

458 193 Particulates 21 80% 80% ESP caoture 99% 366 154 Particulates 21 $29,645 $30,552 $130,143 999 473 Particulates 60 80% 80% ESP caoture 99% 799 378 Particulates 60 $13,578 $12,447 $45,500
*Engineering analysis in 2006 resulted in cost estimate approaching $100 millon for SCR on each Northport Unit Conservate estimate of $70 million based on EPA estimates and Technical References from Hoskin, 2003;Cichanowicz, 2004; and Marano, 2006. $30 million estimate for Barrett Unit 2 developed from above references. $17 million estimate developed from engineering analysis of 1994 which developed a cost of $11 million for an ESP on Barrell Unit 2. Cost from 1994 was adjusted to 2010$.

### October 29, 2010

Scott, The following is in response to your questions of October 26, 2010 regarding SNCR vs. SOFA.

The EPRI, full scale SNCR demonstration project we referred to, took place at National Grid’s Port Jefferson Unit 3 in 1993,with results published in an EPRI Report dated March 1995. A separate report, Design and Cost Estimating Procedures for SNCR, was published in EPRI Report No. 1004123, dated September 2002. On page 3-7 of that report, a NOx reduction of 26% (during steady load) was reported with an NH3 slip of 5%. Somewhat higher NOx reduction rates (approaching 35%with steady state conditions) have been reported in other case studies; however they had much higher baseline NOx emissions than the 0.1 lb/mmbtubaseline (more representative of National Grid’s BART affected units) in the referenced EPRI Report. This compares to a NOx reduction of about 40% with SOFA, withoutthe many negative side effects associated with NH3. The estimated cost of NOxcontrol using SNCR was about $2,300/ton in 2002. This escalates to about $3,500 in 2010($). This cost estimate assumed a 50% capacity factor, while National Grid’s BART affected units are projected to operate with only a 25% capacity factor. This woulddouble the cost estimate to $7000/ton NOx, however $500/ton NOx must be subtracted (based on EPRI’s model) to account for the urea not consumed at the lower capacity factor of 25%, resulting in a cost of $6,500/ton NOx removed. Accounting for higher construction costs in the New York Metro area, relative to the national average (documentedto be at least 20%), the final SNCR cost estimate for NOx removal is about $7,800/ton. In addition to the higher cost, there area number of technical issues with SNCR, which are not associated with SOFA. The most important issue relates to National Grid’s BART affected units operated as load following units which can cycle from minimum load to full load and back to minimum load daily. A steady state NOx reduction of 26% may not be possible for a load following unit without significantly higher NH3 slip rates. This results from the narrow temperature window in which urea reacts in the convective section of the boiler to reduce NOx. Injection at a non optimum temperature can actually increase NOx emissions. With a load following unit, the optimum temperature window migrates along the convective path asthe load changes, making SNCR operation problematic. This results in temporal variations in both NOx control rates, as well as NH3 slip.
Since SNCR has a lower NOx removal efficiency than SOFA and a higher cost (exceeding BART guidelines), and technical issues with units which cycle in load, we selected SOFA as the BART control technology.

### If you have any questions, please give Cathy or I a call. I had worked directly with Bob Teetz, the Project Manager for the EPRI, SNCR Demonstration Project and feel confident that SOFA is the superior technology for National Grid’s BART affected units. GeorgeAs werespondedto you in ouremail ofJune 18,2010, about four years ago, NatiOnal Grid (then KeySpan) undertook an extensive investigationto evaluatethe feasibility ofinstalling an SCRon one oftheNorthportUnits. Afterdiscussions with multiple SCR

### and catalyst vendors, ourPower Engineering Dept. conservativelyestimated $70 million for the cost ofinstallationofan SCRon one Northport wtit. : ; I 

### Facility Name Facility ID -' Emission Point Control Type 1 Cost of Emissions Control Equipment including installation 2 Calculate Capital Recovery Factor Calculate Annual Equipment Cost (Multiply Item 1 by Item 

### 32' 4 Annual Operating Costs (Sum of 4A and 48) 4A Fixed O&M 48 Variable O&M 5 Total Annual Costs (Add Items 3 and 4) Northport Unit 1 SCR 

### $70000,000 0.130 $ 9,100,000 $ 1,750,000 $ 580,000 $ 1,170,000 $10,850,000

As shown above, when the costofcapital, annual equipment costs and O&M are considered, the total annual cost is -$10,850,000. This equates to about $27,000fT'onNOx removedbasedon actual load and emission forecasts for each ofthese units. Based on a 100% capacity factor, the removal costs are ahout S11

### ,0001 ton NOxremoved.

Thetable providedbelow comes from a search oftechnical papers to provide a confrrm.ationof
ourown costestimates. Use ofthe upperrange ofthese estimates, giving a costrange of$64- 80M (mid 2000 dollars), may still inadequatelyrepresentthe constructiondifficulties atNorthport
as well as the high costoflabor in the Metro NY area.

Tabletaken from TheFlTSt lQOGW ofSCR mthe U.S.-What HaveWe Learned? Paper 129, Cichanowicz, et al. Reference Average Capital Low-High Cost Observation I 

### (S/kw) Observed Hoskins, 

### 120 (4ooMW) 80-160 Costbasis: 2002. 15 to 20reported 

### 2003 unit costs exceeded SIOOIkw. Weak relationshio ofunit cost and scale. Cichanowicz, 

### 81 (600-899) to 

### 123 56-t85 Cost Basis:2003. For four categories 

### 2004 (100-399MW) ofgenerating capacitythe leastcost 

### wtits were amonll the first installed Marano, 2006 

### 118 (>900) to 

### 167 Most cost Cost Basis 2005. Units with a capacity 

### «300MW) reportedto be to 600-900 MWto be more difficultto 

### within 

### 100-200 retrofit 

### than those in other size ranges.



### "

Note: An analysis for Barrett Unit 2 provides similarremoval costpertonresults for both an SCRand an ESP forparticulates. All fourNorthportunits have ESPs.l<lOl;;IVIL



### Scott Griffin

- RE: National Grid's Compliance Strategy for NYSDEC NYCRR Part 249 BART Regulations

From: 

### To: 

### Date: Subject: 

### cc:

Hi Scott, "Waxman, Cathy L." <Cathy.Waxman@us.ngrld.com> "Scott Griffin" <slgriffi@gw.dec.state.ny.us>, "Martin, George 

### J." 

### <Gear

... 6/1B/2010 11:22 AM 

### RE: National Grid's Compliance Strategy for NYSDEC NYCRR Part 249 BART Regulations "Corrado, Christopher" <Christopher.Corrado@us.ngrid':"'com> 

## ,.

Here are the responses to your questions.
NOx In 2006 and 2007, in anticipation of pending future regulatory reduction requirements (i.e CAIR, NOx 

### MeT revisions), we began evaluating various NOX control technologies including SCR, SNCR and SOFA. SCR was very thoroughly evaluated from a construction, operation and performance standpoint. This evaluation included in depth discussions with multiple SCR manufacturers and catalyst suppliers. In addition, Computational Fluid Dynamic (CFD) models were used to assist in the design of the SCR system. The result of the evaluation concluded that in addition to this technology not being cost effective ($100 million/unit or a $/ton reduction at least 3 times greater than the BART guidelines), there are numerous structural problems and physical constraints on each unit that would seriously impede the construction of this technology. Also, since all 

### these units are no longer base 

### load units, but are load following, SCR control technology effectiveness degrades with non steady state operation.
SNCR was also evaluated as part of this process in 2006/2007 and had been evaluated In the mid 990s as a EPRI sponsored project hosted by National Grid. This process achieved 

### a NOX reduction 

### no betterthan SOFA, with additional operational constraints (ammonium sulfate and bisulfate production that would affect efficiency and increase particulate emissions).

. SOFA, the recognized state-of-the-art combustion control technology for low NOx operation, was selected as the preferred control technology. A SOFA demonstration program with EPRI was successfully concluded on EFB Unit 

### 2, a 185 MW class unit, in 1995. CFD modeling performed by National Grid in 2008 confirmed the effectiveness of the application of SOFA to the 385 MW class Northport units.

PM for EF Barrett 2 There are a number of ways of reducing particulate emIssions from this unit including the maximization of natural gas use (historical and future projected practice) and/or the installation of an ESP or a baghouse. An ESP for this facility is estimated 

### to cost between $15 -17 million. The historic and future projected low oil bl,Jrn on this unit makes the $/ton reduction far in excess of BART guidelines. A review ofother particulate reduction projects in the industry shows that the 

### cost ofa baghouse is comparable 

### to the ESP. Further, baghouses are better suited for coal units, due to the unfavorable ash properties of oil combustion.

Please let us know if you have any additional 

### questions. Cathy

From: Scott Griffin [maflto:slgriffi@gw.dec.state.ny.us) 

### Sent: ThUrsday, 

### June 17, 2010 10:29 AM 

### To: Martin, George

### J. Cc: Waxman, Cathy L.



### file://C:\Documents 

### and SettingslslgriffilLocal Settings\ TempIXPgrpwise\4C1 B56ECDom... 10/4/2010