Document ID: EPA-HQ-OW-2008-0667-3651
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2014-08-15T04:00Z

MEMORANDUM

Tetra Tech, Inc.
10306 Eaton Place, Suite 340
Fairfax, VA 22030
phone	703-385-6000
fax	703-385-6007

TO:			Lisa Biddle, EPA
FROM:		John Sunda and Kelly Meadows
DATE: 		February 12, 2013 

SUBJECT: 	Analysis of Cooling System Baseline Trends Using EIA Electricity Generator Data
Data from the annual US Energy Information Administration (EIA) Form 860 survey was analyzed to determine the distribution of system type and age of electricity generator cooling systems to characterize industry trends in the usage of cooling system types for large electric generators. These trends are useful in the evaluation of the net impact of various regulatory requirements that affect the selection of cooling system type.  Specifically, the results of this analysis can help identify reasonable estimates of what portion of "new units" (as defined in the 316(b) existing facility rule) would be designed and constructed with closed-cycle cooling or the equivalent in the baseline.
The most recent available data is from the 2011 Form EIA-860 survey.  The file identified as "EnviroEquipY2011.xls" includes data specific to cooling systems. Form EIA-860 "collects data on the status of existing electric generating plants and associated equipment (including generators, boilers, cooling systems and flue gas desulfurization systems) in the United States, and those scheduled for initial commercial operation within 10 years of the specified reporting period." The survey includes requests for data concerning "associated cooling systems." The survey instructions define a cooling system as "an equipment system that provides water to the condensers and includes water intakes and outlets, cooling towers and ponds, pumps, and pipes. Identify a single plant cooling system, not separate systems, unless systems are physically separated, e.g., have separate water intake and outlet structures, where each system can be operated independently." (EIA, 2013) The data from the spreadsheet tab "cooling" was reviewed and found to include a separate row for each associated cooling system, with many plants reporting multiple systems. This analysis treats each system equally.
Data on cooling systems are required only from plants with a generating capacity of 100 MW or more. The exclusion of cooling systems for generating systems less than 100 MW limits the scope of this data to larger plants that might typically require an intake flow of 60 to 120 mgd if operating a once-through cooling system.  As a result, this analysis should include most Phase II generators and also many Phase III generators that operate flow reduction technologies such as closed-cycle cooling. The Proposal TDD Exhibit 4-3 indicates that about 25% of in-scope generating facilities have design intake flows of 2 to 100 mgd. Thus, there should be a considerable amount of overlap with the 316(b) questionnaire database since many of those facilities use closed-cycle cooling.
The EIA Form 860 database also includes a much larger universe of facilities since it includes facilities that would be considered out of scope for 316(b). The data evaluated includes 1,640 cooling systems that are currently operating and is 80% larger than the EPA in-scope estimate of 912 cooling systems (see Proposal TDD Exhibit 4-8). Since the EIA database is limited to cooling water systems, it is similar to the 316(b) questionnaire database in that it does not include generating facilities that do not use cooling water, such as combustion turbines, solar, or hydropower. By including a larger scope of cooling water using generators, this data is especially useful for estimating 316(b) compliance trends for new units since it includes the full range of system design and water sources both in-scope and out-of-scope that would be available to new units.
The analysis evaluated only those systems currently operating and those being constructed or planned. These are identified as:
   * OP - Operating (in commercial service or out of service less than 365 days)
   * CO - Units under construction
   * PL - Planned (expected to go into commercial service within 10 years)
An important data element used in the analysis was the actual or projected "in-service" year of the cooling system. This date is specific to the cooling system and may not necessarily be the same "in-service" date of the generating system. For example, the "in-service" date of a retrofitted cooling system should be the date the retrofitted system began operation, provided the design is substantially different. For repowered systems where no changes were made to the cooling system, the "in-service" date will likely be recorded as the start date for the original cooling system. Thus, the data reflects the cooling system perspective only and there is no way to distinguish a cooling system associated with new Phase I units from those associated with stand-alone/greenfield or repowered units at existing facilities.
In the analysis, the cooling systems were grouped by in-service date by decade; pre-1950, 1960s, 1970s, 1980s, 1990s, 2000-2011(present), and future (under construction and planned). The database included codes for the numerous cooling system configurations and tower types listed in Tables 1 and 2. Table 1 presents the number of cooling systems that fall within each group. Table 2 presents the distribution of cooling system types that began operation within each timeframe. Table 3 collapses many of the cooling system types into groups that would be relevant to the 316(b) regulation. The last row in Table 3 also shows the distribution of existing cooling systems by age.
The database also included the "Design Cooling Water Flow Rate at 100 percent Load at Intake." The average design intake flow per cooling system type and timeframe is shown in Table 4.  The average design intake values are consistent with expected values with closed-cycle being roughly an order of magnitude smaller than once through. 
Baseline Analysis of Closed-Cycle Cooling
Of the cooling system types reported in the database, those that are likely to comply with a requirement to reduce flows commensurate with a closed-cycle system include:
   * Recirculating with pond/canal (impoundment)
   * Recirculating with forced draft tower(s)
   * Recirculating with induced draft tower(s)
   * Recirculating with natural draft tower(s)
   * Recirculating with forced draft hybrid tower(s) with dry cooling
   * Recirculating with induced draft hybrid tower(s) with dry cooling
   * Dry  cooling
   * Other
The data in Table 3 clearly show a steady trend toward the use of closed-cycle cooling, especially after the enactment of the Clean Water Act in 1972. During the 1990's, 84% of new cooling systems were likely to be compliant with a requirement for a closed-cycle recirculating system. The increase to 94% in the 2000's likely reflects the influence of the Phase I 316(b) rule, which was finalized in 2001. Present day data indicate that 98% of new cooling systems are likely to be compliant. This indicates that the baseline compliance value of 50% used in the new unit cost analysis in the proposed rule was likely too conservative (low). A more reasonable value for new construction would be somewhere between 83% and 98%. The value of 83% represents 316(b) BPJ determinations prior to Phase I and should likely be the minimum for greenfield or stand-alone units at existing facilities since Phase I would not apply to these units. The value of 98% may be too high since the basis for this number likely includes many Phase I systems that are required to use closed-cycle cooling. The midpoint value of 90% may be a reasonable estimate for stand-alone or greenfield new unit baseline compliance with a closed-cycle cooling requirement.
Conclusion
A review of the EIA data shows a clear trend towards the use of closed-cycle cooling in recent years for new facilities, and presumably also for new units. As a result, EPA may wish to revise the previous estimates of baseline compliance for new units using the more recent data. Due to the higher rate of expected baseline compliance, is that the estimated economic impact (and benefits) of closed-cycle cooling requirements for new units are much smaller than previously estimated.

References:
EIA. EIA Form 860 Annual Electric Generator Report  -  Instructions. Accessed January 2013.
EIA. Database Spreadsheet: "EnviroEquipY2011.xls" Accessed January 2013.
EIA. Database Spreadsheet: "LayoutY2011.xls" Accessed January 2013.

                                    Table 1
     EIA Form 860 Generator Cooling System Type Counts by In-service Date
                                       
                           Existing Cooling Systems
                              Under Construction
                                    Planned
                                Existing Total
                                 Future Total
In-service Dates
                                   1920-1949
                                   1950-1959
                                   1960-1969
                                   1970-1979
                                   1980-1989
                                   1990-1999
                                   2000-2011
                                   2012-2022
                                   2012-2022
                                   1920-2011
                                   2012-2022
Once-through Freshwater
                                      33
                                      182
                                      138
                                      96
                                      20
                                       6
                                      11
                                       0
                                       1
                                      486
                                       1
Once-through Saltwater
                                       5
                                      51
                                      62
                                      43
                                      11
                                      10
                                       4
                                       0
                                       0
                                      186
                                       0
Once-through Pond/Canal
                                       3
                                       7
                                      17
                                      21
                                       3
                                       0
                                       5
                                       0
                                       0
                                      56
                                       0
Recirculating with Pond/Canal
                                       2
                                       5
                                      21
                                      36
                                      22
                                       1
                                       3
                                       1
                                       0
                                      90
                                       1
Recirculating with Forced Draft Tower(s)
                                       2
                                      21
                                      26
                                      64
                                      59
                                      20
                                      116
                                       5
                                       5
                                      308
                                      10
Recirculating with Induced Draft Tower(s)
                                       0
                                      28
                                      35
                                      59
                                      41
                                      49
                                      153
                                      13
                                      16
                                      365
                                      29
Recirculating with Natural Draft Tower(s)
                                       0
                                       0
                                      11
                                      34
                                      39
                                       6
                                       2
                                       3
                                       0
                                      92
                                       3
Recirculating with Forced Draft Hybrid Tower(s) with Dry Cooling
                                       0
                                       0
                                       0
                                       0
                                       0
                                       0
                                       2
                                       1
                                       0
                                       2
                                       1
Recirculating with Induced Draft Hybrid Tower(s) with Dry Cooling
                                       0
                                       0
                                       0
                                       0
                                       0
                                       0
                                       2
                                       0
                                       0
                                       2
                                       0
Dry  Cooling
                                       0
                                       0
                                       0
                                       1
                                       2
                                       7
                                      42
                                       0
                                      12
                                      52
                                      12
Other
                                       0
                                       0
                                       0
                                       1
                                       0
                                       0
                                       0
                                       0
                                       3
                                       1
                                       3
Total
                                      45
                                      294
                                      310
                                      355
                                      197
                                      99
                                      340
                                      23
                                      37
                                     1640
                                      60

                                    Table 2
  EIA Form 860 Generator Cooling System Type Distribution by In-service Date
 
                           Existing Cooling Systems
                              Under Construction
                                    Planned
                                Existing Total
                                 Future Total
In-service Dates
                                   1920-1949
                                   1950-1959
                                   1960-1969
                                   1970-1979
                                   1980-1989
                                   1990-1999
                                   2000-2011
                                   2012-2022
                                   2012-2022
                                   1920-2011
                                   2012-2022
Once-through Freshwater
                                      73%
                                      62%
                                      45%
                                      27%
                                      10%
                                      6%
                                      3%
                                      0%
                                      3%
                                      30%
                                      2%
Once-through Saltwater
                                      11%
                                      17%
                                      20%
                                      12%
                                      6%
                                      10%
                                      1%
                                      0%
                                      0%
                                      11%
                                      0%
Once-through Pond/Canal
                                      7%
                                      2%
                                      5%
                                      6%
                                      2%
                                      0%
                                      1%
                                      0%
                                      0%
                                      3%
                                      0%
Recirculating with Pond/Canal
                                      4%
                                      2%
                                      7%
                                      10%
                                      11%
                                      1%
                                      1%
                                      4%
                                      0%
                                      5%
                                      2%
Recirculating with Forced Draft Tower(s)
                                      4%
                                      7%
                                      8%
                                      18%
                                      30%
                                      20%
                                      34%
                                      22%
                                      14%
                                      19%
                                      17%
Recirculating with Induced Draft Tower(s)
                                      0%
                                      10%
                                      11%
                                      17%
                                      21%
                                      49%
                                      45%
                                      57%
                                      43%
                                      22%
                                      48%
Recirculating with Natural Draft Tower(s)
                                      0%
                                      0%
                                      4%
                                      10%
                                      20%
                                      6%
                                      1%
                                      13%
                                      0%
                                      6%
                                      5%
Recirculating with Forced Draft Hybrid Tower(s) with Dry Cooling
                                      0%
                                      0%
                                      0%
                                      0%
                                      0%
                                      0%
                                      1%
                                      4%
                                      0%
                                      0%
                                      2%
Recirculating with Induced Draft Hybrid Tower(s) with Dry Cooling
                                      0%
                                      0%
                                      0%
                                      0%
                                      0%
                                      0%
                                      1%
                                      0%
                                      0%
                                      0%
                                      0%
Dry  Cooling
                                      0%
                                      0%
                                      0%
                                      0%
                                      1%
                                      7%
                                      12%
                                      0%
                                      32%
                                      3%
                                      20%
Other
                                      0%
                                      0%
                                      0%
                                      0%
                                      0%
                                      0%
                                      0%
                                      0%
                                      8%
                                      0%
                                      5%
Total
                                     100%
                                     100%
                                     100%
                                     100%
                                     100%
                                     100%
                                     100%
                                     100%
                                     100%
                                     100%
                                     100%

                                    Table 3
  EIA Form 860 Generator Cooling System Type Distribution by In-service Date
 
                           Existing Cooling Systems
                              Under Construction
                                    Planned
                                Existing Total
                                 Future Total
In-service Dates
                                   1920-1949
                                   1950-1959
                                   1960-1969
                                   1970-1979
                                   1980-1989
                                   1990-1999
                                   2000-2011
                                   2012-2022
                                   2012-2022
                                   1920-2011
                                   2012-2022
Once-Through (including Once-through Pond/Canal)
                                      91%
                                      82%
                                      70%
                                      45%
                                      17%
                                      16%
                                      6%
                                      0%
                                      3%
                                      44%
                                      2%
Recirculating Pond/Canal
                                      4%
                                      2%
                                      7%
                                      10%
                                      11%
                                      1%
                                      1%
                                      4%
                                      0%
                                      5%
                                      2%
Recirculating Tower
                                      4%
                                      17%
                                      23%
                                      44%
                                      71%
                                      76%
                                      80%
                                      91%
                                      57%
                                      47%
                                      70%
Recirculating Hybrid Tower
                                      0%
                                      0%
                                      0%
                                      0%
                                      0%
                                      0%
                                      1%
                                      4%
                                      0%
                                      0%
                                      2%
Dry  Cooling
                                      0%
                                      0%
                                      0%
                                      0%
                                      1%
                                      7%
                                      12%
                                      0%
                                      32%
                                      3%
                                      20%
Likely 316(b) Compliant for Closed-Cycle Cooling[1]
                                      9%
                                      18%
                                      30%
                                      55%
                                      83%
                                      84%
                                      94%
                                     100%
                                      97%
                                      56%
                                      98%
Cooling System Count
                                      45
                                      294
                                      310
                                      355
                                      197
                                      99
                                      340
                                      23
                                      37
                                     1640
                                      60
Distribution of Cooling Systems[2]
                                      3%
                                      18%
                                      19%
                                      22%
                                      12%
                                      6%
                                      21%
                                     1.4%
                                     2.3%
                                     100%
                                     3.7%
Includes only systems currently operating, under construction or planned in next 10 years
[1] Includes Recirculating Towers, Dry Cooling and Other (all "Other" systems did not use surface water as source)
[2] Distribution relative to total existing

                                    Table 4
EIA Form 860 Generator Cooling System Average Intake Design Flow by Type and In-service Date

 
                           Existing Cooling Systems
                              Under Construction
                                    Planned
                                Existing Total
                                 Future Total
In-service Dates
                                   1920-1949
                                   1950-1959
                                   1960-1969
                                   1970-1979
                                   1980-1989
                                   1990-1999
                                   2000-2011
                                   2012-2022
                                   2012-2022
                                   1920-2011
                                   2012-2022
Units
                                      mgd
                                      mgd
                                      mgd
                                      mgd
                                      mgd
                                      mgd
                                      mgd
                                      mgd
                                      mgd
                                      mgd
                                      mgd
Once-through Freshwater
                                      235
                                      203
                                      216
                                      551
                                      540
                                      591
                                      264
                                       -
                                       1
                                      298
                                       1
Once-through Saltwater
                                      181
                                      147
                                      302
                                      697
                                      890
                                      262
                                      202
                                       -
                                       -
                                      378
                                       -
Once-through Pond/Canal
                                      568
                                      303
                                      259
                                      676
                                      393
                                       -
                                      441
                                       -
                                       -
                                      461
                                       -
Recirculating with Pond/Canal
                                      100
                                      118
                                      381
                                      394
                                      294
                                      267
                                      359
                                      360
                                       -
                                      342
                                      360
Recirculating with Forced Draft Tower(s)
                                       4
                                      47
                                      38
                                      70
                                      51
                                      32
                                      24
                                       3
                                       2
                                      42
                                       2
Recirculating with Induced Draft Tower(s)
                                       -
                                      27
                                      31
                                      60
                                      17
                                      12
                                      17
                                       9
                                      73
                                      25
                                      44
Recirculating with Natural Draft Tower(s)
                                       -
                                       -
                                      29
                                      21
                                      29
                                      46
                                       8
                                      21
                                       -
                                      27
                                      21
Recirculating with Forced Draft Hybrid  Tower(s) with Dry Cooling
                                       -
                                       -
                                       -
                                       -
                                       -
                                       -
                                       4
                                       1
                                       -
                                       4
                                       1
Recirculating with Induced Draft Hybrid Tower(s) with Dry Cooling
                                       -
                                       -
                                       -
                                       -
                                       -
                                       -
                                       5
                                       -
                                       -
                                       5
                                       -
Dry  Cooling
                                       -
                                       -
                                       -
                                       0
                                       0
                                       0
                                       0
                                       -
                                       0
                                       0
                                       0
Other
                                       -
                                       -
                                       -
                                       2
                                       -
                                       -
                                       -
                                       -
                                       4
                                       2
                                       4
All
                                      235
                                      167
                                      204
                                      338
                                      168
                                      80
                                      37
                                      24
                                      32
                                      181
                                      29