# Date : September 30 , 2011

**Subject:** National Emission Standards for Hazardous Air Pollutants (NESHAP)

for Coal

- and Oil

- Fired Electric Utility Steam Generating Units Response to Comments Regarding Inaccurate Heat Rates in MACT Floor Analys is

**From:** Shelly Johnson

**To:** William Maxwell

OAQPS/SPPD/ESG (D243

- 01) U.S. Environmental Protection Agency Research Triangle Park, NC 27711

I. Background The EPA proposed National Emission Standards for Hazardous Air Pollutants (NESHAP) for Coal

- and Oil

-Fired Electric Utility Steam Generating Units (EGUs) on May 3, 2011. The public comment period ended on July 5, 2011. The Electric Power Research Institute (EPRI) commented on the unit heat rates used in the maximum achievable control technology (MACT) floor analys is . They stated, “Heat rates were calculated incorrectly for 53 EGUs listed in the MACT floor spreadsheets. These errors resulted in emissions on a pound per megawatt

-hour (lb/MWh) basis that are two to six times too low. EGUs affected by this error include several identified as lowest emitting in the MACT floor spreadsheets.” In addition to this comment, EPA has received other comments indicating that the heat rate s used to convert emissions on a lb/MMBtu basis to a lb/MWh basis are not realistic

. This memorandum addresses the work done to identify facilities with heat rates that appear to be inaccurate, and to revise that information in the EGU MACT Information Collection Request (ICR) database.

II. Discussion
The heat rates used in the MACT floor analys is are calculated based on data provided by each company in response to the E GU MACT ICR. The boiler information table contains detailed boiler

- specific operating parameters for each boiler at a facility

. These parameters include the present maximum heat input (MMBtu/hr) and summer gross generating capacity (MWe) . These company-provided parameters are used to calculate the heat rate for each boiler . The heat rate i s calculated by dividing the maximum heat input by the summer gross generating capacity to obtain a heat rate in units of MMBtu/MWh

.

# 2



# Most boilers have a calculated heat rate between 8 and 14 MMBtu/MWh. The boilers with calculated heat rates lower than 8 MMBtu/MWh , and plants with multiple boilers serving one generator were reviewed to confirm the maximum heat input and summer gross generating capacity values that were provided in response to the ICR

. The most common reason for the low calculated heat rates is that the generation values for the turbine generator were entered for each boiler that supplies steam to the generator. For instance, if twin boilers provide steam to a single turbine generator that produces 200 MW of electricity, each boiler is (ostensibly) responsible for one
-half of the electricity generated

. Therefore, the summer gross generating capacity value should have been reported as 100 MWe for each boiler; however, in many cases the full 200 MW was entered as the capacity for each boiler.

III. Conclusion
In total , 25 facilities were contacted to confirm the maximum heat inputs and gross generating c apacities of 59 boilers. All of the 53 units EPRIsuggested are included in the 59 boilers that were corrected. For the 11 facilities that did not respond to our request for additional information, the heat inputs and generating capacities were revised bas ed on information included in the NEEDS database (v4.10)

. The original values from the ICR response and the corrected values are shown in Attachment 1 , Table A

- 1 . All revisions have been made in the ICR database and will be reflected in future outputs of the MACT floor data.

# 3 

# ATTACHMENT 1

# 4



# Table A

- 1 : Boilers with corrected maximum heat inputs and summer gross generating capacities.

**ORIS Code**  **Boi ler** 

**ID Ori**  **gi nal**  **M ax**  **He at Input**  **Ori gi**  **nal**

**Summe r G**  **ross Gen**  **er ati**  **ng Capacity**  **Origina l Unit** 

**He at Rate**  **New Max**

**He at Input**  **New Summe r** 

**Gr oss**  **Gen er** **ating Capaci**  **ty Ne**  **w U nit Heat** 

**Rate Source**  **o f Confir** **mati on** 

MMB tu/hr MWe MMBtu/M Wh MMBtu/hr Mw e MMBtu/M Wh 508 4 180 44.0 4. 09 510 44. 0 11. 59 Company contact 703 3 7, 284 933.0 7. 81 8,185 933.0 8.77 NE EDScompari son 1004 6- 1 510 171.0 2. 98 510 42.8 11. 93 NE EDScompari son 1004 7- 1 510 171.0 2. 98 510 42.8 11. 93 NE EDScompari son 1004 7- 2 510 171.0 2. 98 510 42.8 11. 93 NE EDScompari son 1004 8- 1 510 171.0 2. 98 510 42.8 11. 93 NE EDScompari son 2526 11 273 46.0 5. 93 273 23. 0 11. 87 NE EDScompari son 2526 12 273 46.0 5. 93 273 23. 0 11. 87 NE EDScompari son 2712 3A 3, 460 741.0 4. 67 3,460 370.5 9.34 Company contact 2712 3B 3, 460 741.0 4. 67 3,460 370.5 9.34 Company contact 2712 4A 3, 469 745.0 4. 66 3,469 372.5 9.31 Company contact 2712 4B 3, 469 745.0 4. 66 3,469 372.5 9.31 Company contact 2864 5 647 100.0 6. 47 647 50. 0 12. 94 NE EDScompari son 2864 6 647 100.0 6. 47 647 50. 0 12. 94 NE EDScompari son 3178 1 1, 250 184.0 6. 79 1,749 184.0 9.51 Company contact 3178 2 1, 204 183.0 6. 58 1,706 183.0 9.32 Company contact 3776 51 572 100.0 5. 72 572 50.0 11. 44 Company contact 3776 52 572 100.0 5. 72 572 50.0 11. 44 Company contact 6190 3- 1 2, 808 703.8 3. 99 2,808 351.9 7.98 NE EDScompari son 6190 3- 2 2, 808 703.8 3. 99 2,808 351.9 7.98 NE EDScompari son 6250 1A 3, 743 792.0 4. 73 3,743 396.0 9.45 Company contact 6250 1B 3, 743 792.0 4. 73 3,743 396.0 9.45 Company contact 7537 1A 614 90.0 6. 82 614 45.0 13. 64 Company contact 7537 1B 629 90.0 6. 99 629 45.0 13. 98 Company contact 8048 1 3, 669 517.0 7. 10 4,964 535. 0 9.28 Company contact 8048 2 3, 933 525.0 7. 49 4,850 525. 0 9.24 Company contact 10151 BLR1A 675 95.0 7. 11 675 47.5 14. 21 Company contact 10151 BLR1B 675 95.0 7. 11 675 47.5 14. 21 Company contact 10384 1A 375 61.0 6. 15 375 30.5 12. 30 Company contact 10384 1B 375 61.0 6. 15 375 30.5 12. 30 Company contact 10384 2A 375 61.0 6. 15 375 30.5 12. 30 Company contact 10384 2B 375 61.0 6. 15 375 30.5 12. 30 Company contact 10566 Boil 1 1, 387 285.0 4. 87 1,387 142.5 9.73 Company contact 10566 Boil 2 1, 387 285.0 4. 87 1,387 142.5 9.73 Company contact 10671 1A 3, 553 283.9 12. 51 1,110 80. 0 13. 88 Company contact 10671 1b 3, 553 283.9 12. 51 1,110 80. 0 13. 88 Company contact 10671 2a 3, 553 283.9 12. 51 1,110 80. 0 13. 88 Company contact 10671 2b 3, 553 283.9 12. 51 1,110 80. 0 13. 88 Company contact 10672 CBA 1, 063 280.0 3. 80 1,063 92.0 11. 55 Company contact 10672 CBB 1, 063 280.0 3. 80 1,063 92.0 11. 55 Company contact 10672 CBC 1, 063 280.0 3. 80 1,063 92.0 11. 55 Company contact 10673 BLR A 1, 021 203.0 5. 03 1,021 101.5 10. 06 NE EDScompari son 10673 BLR B 944 203.0 4. 65 944 101.5 9.30 NE EDScompari son 10675 A 1, 002 208.0 4. 82 1,002 104.0 9.63 NE EDScompari son 10675 B 1, 002 208.0 4. 82 1,002 104.0 9.63 NE EDScompari son 10676 2 550 135.0 4. 07 550 38.4 14. 32 NE EDScompari son 10676 3 550 135.0 4. 07 550 38.4 14. 32 NE EDScompari son 10676 4 550 135.0 4. 07 550 38.4 14. 32 NE EDScompari son 10676 5 285 135.0 2. 11 285 19.8 14. 39 NE EDScompari son 10743 CFB1 457 58.0 7. 88 457 29. 0 15. 76 NE EDScompari son 10743 CFB2 453 58.0 7. 81 453 29. 0 15. 62 NE EDScompari son 10771 10771- 01 433 68.0 6. 37 433 34.0 12. 74 Company contact 10771 10771- 02 422 68.0 6. 21 422 34.0 12. 41 Company contact 10774 1 442 68.0 6. 50 442 34.0 13. 00 Company contact 10774 2 447 68.0 6. 57 447 34.0 13. 15 Company contact 50835 1 408 64.4 6. 34 408 32.2 12. 67 NE EDScompari son 50835 2 408 64.4 6. 34 408 32.2 12. 67 NE EDScompari son 50974 #1 CFB boi ler 650 97.0 6. 70 650 48.5 13. 40 NE EDScompari son 50974 #2 CFB Bo iler 600 97.0 6. 19 600 48.5 12. 37 NE EDScompari son