nationalgrid

September 27, 20 I0

Mr. Scott Griffin

Environmental Engineer 1

NYSDEC Division of Air Resources

Bureau of Air Quality Planning

625 Broadway, 2"" Floor

Albany, New York 12233-3251

HJt:r'VI!O

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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 generating units which arc

subject to Part 249 BART Regulations. These units include Northport Units 1,2,3 and 4

(385Mw each, primarily natural gas fired, with backup oil firing capability) and E. F.

Barrett Unit 2 (185 Mw, natural gas fired, with oil backup for use in the event of a natural

gas shortage).

National Grid's BART Compliance Demonstration incorporates the guidelines

presented by the NYSDEC on March 3, 2010 at their Albany 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 Over Fire Air

(SOFA) (analysis not shown) was selected as the BART control technology, since its

control cost per ton of NOx is below the $5500 threshold. SOFA technology is

recognized by EPA as the most advanced, state of the art combustion control technology

for NOx. 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) beginning January 1.

175 East Old Coultry Road. Hicks\IiIe. NY 11801. www.nationalgrid.com
nationalgrid

Mr. Scott Griffin

September 27, 2010

Page Two

2014, as required by the BART Regulations. The oil emission limit will he asswned

during any 24 hour averaging period, when oil is fired.

. As provided in 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 at Northport Units I, 2, 3 and 4 to 0.7% (30% below

the 6 NYCRR Part 225-1 limit of 1.0%). The fuel sulfur content 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 particulate matter, an analysis combination of factors, including cost and

feasibility of additional 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. Barrett Unit 2 is a natural gas fired unit

with low sulfur (0.37%) oil used as a backup in the event of gas shortages. Due to the

very low 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 office on June 15, June 18 and August 27, 2010, illustrates that even with

conservative construc;:tion cost estimates and the assumption of full load operation for

100% ofthe time, SCR's for NOx control are well above the $5500/ton BART threshold

at Northport Units I, 2, 3 and 4 (identical) and Barrett Unit 2. The cost of an

Electrostatic Precipitator for particulate control at Barrett Unit 2 is also well above the

$5500/ton BART threshold.
nationalgrid

Mr. Scott Griffin

September 27,2010

Page Three

If you have any questions regarding this analysis or further questions regarding

the supporting material previously forwarded to your office at your request, please

contact either George Martin (516) 545-2575 or Cathy 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/mmbtu baseline (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, without the many negative side effects associated 

with NH3. The estimated cost of NOx control 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 would double 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 (documented to be at least 20%), the final SNCR cost 

estimate for NOx removal is about $7,800/ton. 

 In addition to the higher cost, there are a 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 as the 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. 

George 
As we responded to you in our email ofJune 18,2010, about four years ago, NatiOnal Grid (then

KeySpan) undertook an extensive investigation to evaluate the feasibility ofinstalling an SCR on

one ofthe Northport Units. After discussions with multiple SCR and catalyst vendors, our Power

Engineering Dept. conservatively estimated $70 million for the cost ofinstallation of an SCR on

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

32'

Calculate Annual Equipment Cost (Multiply Item 1 by Item

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 cost of capital, annual equipment costs and O&M are considered, the

total annual cost is -$10,850,000. This equates to about $27,000fT'on NOx removed based on

actual load and emission forecasts for each ofthese units. Based on a 100% capacity factor, the

removal costs are ahout S11 ,0001 ton NOx removed.

The table provided below comes from a search oftechnical papers to provide a confrrm.ation of

our own cost estimates. Use ofthe upper range ofthese estimates, giving a cost range of $64-

80M (mid 2000 dollars), may still inadequately represent the construction difficulties at Northport

as well as the high cost oflabor in the Metro NY area.

Table taken from The FlTSt lQOGW ofSCR m the U.S.-What Have We Learned? Paper 129,

Cichanowicz, et al.

Reference Average Capital Low-High Cost Observation

I (S/kw) Observed

Hoskins, 120 (4ooMW) 80-160 Cost basis: 2002. 15 to 20 reported

2003 unit costs exceeded SIOOIkw. Weak

relationshio of unit cost and scale.

Cichanowicz, 81 (600-899) to 123 56-t85 Cost Basis:2003. For four categories

2004 (100-399MW) of generating capacity the least cost

wtits were amonll the first installed

Marano, 2006 118 (>900) to 167 Most cost Cost Basis 2005. Units with a capacity

«300MW) reported to be to 600-900 MW to be more difficult to

within 100-200 retrofit than those in other size ranges.

"

Note: An analysis for Barrett Unit 2 provides similar removal cost per ton results for both an

SCR and an ESP for particulates. All four Northport units 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 better than 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 of other particulate reduction

projects in the industry shows that the cost of a 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\4C1B56ECDom... 10/4/2010