Technical Support Document for 

Calculating Carbon Pollution Goals for Existing 

Power Plants in Territories and Areas of Indian 

Country 

October 2014
TSD for Calculating Carbon Pollution Goals for Existing Power Plants in Territories and Areas of Indian Country

i

CONTENTS 

Acronyms and initialisms.............................................................................................................................. ii

Introduction ..................................................................................................................................................1

Affected electricity generating units on tribal lands ....................................................................................1

Overview...................................................................................................................................................1

Data...........................................................................................................................................................2

BSER factors informing tribal lands’ emission rate goals..........................................................................3

Building block 1 – heat rate improvement at coal-fired power plants.................................................3

Building block 2 – redispatch to lower-emitting NGCC EGUs...............................................................3

Building block 3 – renewables ..............................................................................................................4

Building block 4 – energy efficiency......................................................................................................4

Affected electricity generating units in U.S. territories................................................................................4

Overview...................................................................................................................................................4

Data...........................................................................................................................................................7

BSER factors informing territories’ emission rate goals .........................................................................11

Building block 1 – heat rate improvement at coal-fired power plants...............................................11

Building block 2 – redispatch to lower-emitting NGCC EGUs.............................................................11

Building block 3 – renewables ............................................................................................................11

Building block 4 – energy efficiency....................................................................................................12

Appendix 1 – Tribal and Territory Unit-level Inventory ..............................................................................13

Appendix 2 – Goal Data and Computation .................................................................................................13

Appendix 3 – Cost Calculations...................................................................................................................13

Appendix 4 – Summary of tribal and territory goals under the proposed Existing Source Performance 

Standard......................................................................................................................................................14

Proposed and alternate goals with approach A......................................................................................14

Co-proposed and alternate goals with approach B ................................................................................14

Alternative goals.....................................................................................................................................14

Appendix 5 – 2012 emission rate and building block application ..............................................................15

Proposed goals........................................................................................................................................15

 
TSD for Calculating Carbon Pollution Goals for Existing Power Plants in Territories and Areas of Indian Country

ii

ACRONYMS AND INITIALISMS 

BSER best system of emission reduction

CC combined cycle

CO2 carbon dioxide

CT combustion turbine

EGU electric generating unit

GHG greenhouse gas

GPA Guam Power Authority

ICE internal combustion engine

LNG liquified natural gas

NGCC natural gas combined cycle

PREPA Puerto Rico Electric Power Authority

ST steam turbine

VIWAPA U.S. Virgin Islands Water and Power Authority
TSD for Calculating Carbon Pollution Goals for Existing Power Plants in Territories and Areas of Indian Country

1

INTRODUCTION 

In the June 2014 Carbon Pollution Emission Guidelines for Existing Stationary Sources: Electric Utility 

Generating Units (hereafter referred to as “June 2014 proposed rule”), EPA proposed to establish carbon 

dioxide (CO2) emission guidelines for existing electricity generating units (EGUs) in the 50 states of the U.S. 

The Agency also indicated that it would propose a supplemental rule that included CO2 guidelines for 

existing EGUs in the territories and areas of Indian country (hereafter referred to as “tribal lands”). 

Based on the June 2014 proposed rule, the Agency identified the best system of emission reduction (BSER) 

that, taking into account the cost of achieving emission reductions and non-air quality health and 

environmental impact and energy requirements, the Administrator determines has been adequately 

demonstrated. Based on its evaluation of adequately-demonstrated greenhouse gas (GHG) abatement 

measures, the Agency listed four categories, or “building blocks,” that are technically viable and broadly 

applicable, and can provide cost-effective reductions in CO2 emissions from existing EGUs. These “building 

blocks” include:

1. Reducing the CO2 intensity of generation at individual affected EGUs through heat rate 

improvements;

2. Reducing emissions from the most CO2-intensive affected EGUs in the amount that results from 

substituting generation at those EGUs with generation from less CO2-intenstive affected EGUs 

(e.g., natural gas combined cycle (NGCC) EGUs);

3. Reducing emissions from affected EGUs in the amount that results from substituting generation 

at those EGUs with expanded generation at low- or zero-CO2 EGUs; and,

4. Reducing emissions from affected EGUs in the amount that results from the use of demand-side 

energy efficiency that reduces the amount of generation required.

The Agency believes that for purposes of Clean Air Act section 111(d), as applied to the power sector, the 

BSER encompasses all four “building blocks.”

This Technical Support Document (TSD) describes how the Agency applied the BSER from the June 2014 

proposed rule to affected EGUs on tribal lands and in territories. 

AFFECTED ELECTRICITY GENERATING UNITS ON TRIBAL LANDS 

Overview 

There are four power plants with 12 affected EGUs on tribal lands (see Table 1). Three plants combust 

coal and one plant has two NGCC EGUs. The EGUs on tribal lands operate as part of an integrated 

electricity grid and supply the majority of their electricity generation to customers outside the tribal lands. 

The Agency did not find any information about grid-connected renewable energy generation in 2012 on 

tribal lands with affected EGUs and, therefore, assumed no existing renewable energy sources.
TSD for Calculating Carbon Pollution Goals for Existing Power Plants in Territories and Areas of Indian Country

2

Table 1: Potentially affected EGUs on tribal lands

Tribe ORIS Plant name Unit Fuel Unit type Capacity 

(MW)

Navajo 2442 Four Corners 1 coal steam turbine 190

Navajo 2442 Four Corners 2 coal steam turbine 190

Navajo 2442 Four Corners 3 coal steam turbine 253

Navajo 2442 Four Corners 4 coal steam turbine 818

Navajo 2442 Four Corners 5 coal steam turbine 818

Navajo 4941 Navajo Generating Station NAV1 coal steam turbine 803

Navajo 4941 Navajo Generating Station NAV2 coal steam turbine 803

Navajo 4941 Navajo Generating Station NAV3 coal steam turbine 803

Ute 7790 Bonanza 1 coal steam turbine 500

Fort Mojave 55177 South Point Energy Center A gas NGCC 236

Fort Mojave 55177 South Point Energy Center B gas NGCC 236

Fort Mojave 55177 South Point Energy Center ST1 gas NGCC 236

Data 

The 2012 CO2 emissions and electricity generation data for the EGUs listed in Table 1 are taken from the 

document titled, 2012 Unit-level Data Using the eGRID Methodology.

1

Information about the source of 

these data and the methodologies used to compile the data set is described in Description of 2012 UnitLevel Data Using the eGRID Methodology.

2

The information available to the Agency indicates there was no generation from utility-scale, gridconnected renewable energy in 2012 in the three tribal lands with affected EGUs. This was based on a 

review of information from EIA, DOE’s Office of Indian Energy Policy and Programs, and tribal utility 

authorities serving tribal lands with affected EGUs.

Data required for the calculation of building block 4 goals for tribal lands and their sources are:

 2012 electricity sales (MWh): Form EIA-8613

 2012 energy efficiency incremental effects – total (MWh): Form EIA-8614

 Projected annual electricity sales by region (2012-2040): AEO2013 Reference Case5

These data are inputs to the supporting technical files to this TSD:

 Option 1A: Building block 4 proposed goal based on each tribe/territory ramping up to 1.5% 

incremental savings with costs calculated using a 3% discount rate;

 Option 1B: Building block 4 proposed goal based on each tribe/territory ramping up to 1.5% 

incremental savings with costs calculated using a 7% discount rate;

 

1 Available in the docket EPA-HQ-OAR-2013-0602 at http://www.regulations.gov/#!documentDetail;D=EPA-HQOAR-2013-0602-0254.

2 2 Available in the docket EPA-HQ-OAR-2013-0602 at http://www.regulations.gov/#!documentDetail;D=EPA-HQOAR-2013-0602-0257.

3 Available at http://www.eia.gov/electricity/data/eia861/ (see “retail sales” workbook).

4 Available at http://www.eia.gov/electricity/data/eia861/ (see “dsm” workbook).

5 Available at http://www.eia.gov/forecasts/archive/aeo13/. 
TSD for Calculating Carbon Pollution Goals for Existing Power Plants in Territories and Areas of Indian Country

3

 Option 2A: Building block 4 alternative goal based on each tribe/territory ramping up to 1.0% 

incremental savings with costs calculated using a 3% discount rate; and

 Option 2B: Building block 4 alternative goal based on each tribe/territory ramping up to 1.0% 

incremental savings with costs calculated using a 7% discount rate.

Table 2 summarizes data on 2012 electricity sales for tribal lands by state and utility. None of the tribes 

reported energy efficiency data on their Form EIA-861 submittals for 2012. Projected annual electricity 

sales by region are included in the supporting technical files to this TSD.

Table 2: 2012 total electricity sales for tribal lands

Tribe Utility number Utility name State Total sales

(MWh)

Ute 12866 Moon Lake Electric Assn Inc UT 470,007

Navajo 13314 Navajo Tribal Utility Authority AZ 548,934

Navajo 13314 Navajo Tribal Utility Authority NM 117,010

Navajo 13314 Navajo Tribal Utility Authority UT 10,070

Fort Mojave 58123 Aha Macav Power Service AZ 47,788

BSER factors informing tribal lands’ emission rate goals 

The methodology for calculating tribal lands’ emission rate goals generally applies the same approach to 

determining BSER as described in the Goal Computation TSD from the June 2014 proposed rule. 

Information about the BSER measures can be found in the GHG Abatement Measures TSD.

6 The GHG 

Abatement Measures TSD describes the categories of emission reduction measures (building blocks) used 

in determining the emission rate goals. 

Building block 1 – heat rate improvement at coal-fired power plants

Using the data discussed above, the Agency applied a 6% heat rate improvement to the EGUs at the Four 

Corners, Navajo Generating Station, and Bonanza coal-fired power plants. To calculate the alternative goal, 

the Agency applied a 4% heat rate improvement to the EGUs. The results from building block 1 are 

presented in Table 3.

Table 3: Adjusted average coal CO2 emission rate for coal-fired EGUs

Tribe 6% HRI

Coal CO2 rate 

(lbs/MWh)

4% HRI

Coal CO2 rate 

(lbs/MWh)

Navajo 1,993 2,036

Ute 2,016 2,059

Building block 2 – redispatch to lower-emitting NGCC EGUs

Because none of the tribal lands have both coal-fired EGUs and NGCC EGUs, the analysis does not include 

redispatch to less CO2-intenstive affected EGUs.

 

6 Available in the docket EPA-HQ-OAR-2013-0602 at http://www.regulations.gov/#!documentDetail;D=EPA-HQOAR-2013-0602-0437.
TSD for Calculating Carbon Pollution Goals for Existing Power Plants in Territories and Areas of Indian Country

4

Building block 3 – renewables

The analysis of renewable energy for building block 3 used the proposed methodology from the June 2014 

proposed rule. Because EPA did not find any information about utility-scale, grid-connected renewable 

energy net generation on tribal lands with affected EGUs in 2012, the renewables targets are zero, and, 

therefore, result in no change to the goals for these areas.

EPA did not propose renewable energy targets for goal calculations based on the co-proposed 

methodology for the U.S. territories or the alternative approach used in the June 2014 proposed rule as 

discussed in the preamble. However, EPA considered using the renewable energy technical potential 

estimates for tribal lands7,8 as well as using the lowest renewable energy percentage target (as derived in 

the alternative approach upon which EPA solicited comment for states) of any state in which that area of 

Indian country is located. Because these co-proposed methodology and alternative approach are based 

on a state or territory’s total net electricity generation and not retail sales (i.e., consumption), applying 

these methodologies to tribal lands – where sales are only 2% - 16% of generation – yields large renewable 

energy goals relative to retail sales.

Building block 4 – energy efficiency

The analysis of energy efficiency for building block 4 used the proposed methodology from the June 2014 

proposed rule.

AFFECTED ELECTRICITY GENERATING UNITS IN U.S. TERRITORIES 

Overview 

The territories of Guam, Puerto Rico, and the US Virgin Islands have coal-, oil-, and/or gas-fired EGUs that 

may be affected by this proposal. Data from these EGUs were analyzed to establish territorial goals using 

the BSER described above.

The Guam Power Authority (GPA) owns and manages the territory’s electricity grid. The majority of 

electricity on Guam is generated from No. 6 heavy fuel oil with a small amount from No. 2 distillate oil, 

both of which are shipped to the territory by tanker. 9 There are nine fossil-fired EGUs in Guam equal to 

or greater than 25 MW nameplate capacity (see Table 4). Excluding Guam’s internal combustion engines 

(ICEs) and oil-fired combustion turbines (CTs),10 there are four EGU heavy fuel oil-fired steam turbine (STs) 

EGUs that may be affected sources under the rule.

Guam is also pursuing renewable energy and energy efficiency. In 2008, Guam’s legislature established a 

renewable energy goal of 8% of net electricity sales by December 31, 2020; 10% of net electricity sales by 

December 31, 2025; and 15% of net electricity sales by December 31, 2030.

11

 

7 Doris et al (DOE), 2013. Geospatial Analysis of Renewable Energy Technical Potential on Tribal Lands. Available at 

http://www.nrel.gov/docs/fy13osti/56641.pdf. 

8

Lopez et al (NREL), 2012. U.S. Renewable Energy Technical Potentials: A GIS-Based Analysis. Available at 

http://www.nrel.gov/docs/fy12osti/51946.pdf. 

9 EIA, 2013. Guam – Territory Energy Profile Analysis. Available at http://www.eia.gov/state/analysis.cfm?sid=gq. 

10 The June 2014 proposed rule does not include ICEs as affected sources, and CTs must combust natural gas for 

more than 90% of the CT’s heat input. Since available data indicate Guam’s CT did not combust natural gas, it has 

been excluded from the list of potentially affected units for purposes of this goal-setting analysis.

11 NCSU, 2014. Guam – Renewable Energy Portfolio Goal. Available at 

http://www.dsireusa.org/incentives/incentive.cfm?Incentive_Code=GU03R&ee=1.
TSD for Calculating Carbon Pollution Goals for Existing Power Plants in Territories and Areas of Indian Country

5

Table 4: Guam fossil-fired EGUs equal to or greater than 25 MW capacity

Plant name (location) Unit Fuel Unit type Capacity 

(MW)

Cabras 1 No. 6 oil ST 60 *

Cabras 2 No. 6 oil ST 60 *

Cabras 3 No. 6 oil ICE 38

Cabras 4 No. 6 oil ICE 38

Tanguisson 1 No. 6 oil ST 25 *

Tanguisson 2 No. 6 oil ST 25 *

PITI 7 distillate oil CT 40

PITI 8 No. 6 oil ICE 40

PITI 9 No. 6 oil ICE 40

Note: EGUs with asterisks were included in the goal calculation for Guam

The Puerto Rico Electric Power Authority (PREPA) owns and manages the territory’s electricity grid. In 

2012, approximately 65% of the electricity was generated from No. 6 heavy fuel oil and No. 2 distillate oil, 

18% from liquified natural gas (LNG), 16% from coal, and 1% from hydro.12 There are several fossil-fired 

EGUs in Puerto Rico equal to or greater than 25 MW nameplate capacity (see Table 5). Excluding oil-fired 

CTs and combined cycles (CCs),

13 there are 2 coal-fired ST EGUs, 2 NGCC EGUs, and 14 oil-fired ST EGUs

that may be affected sources under the rule. 

Puerto Rico is also pursuing renewable energy and energy efficiency. In 2010, Puerto Rico enacted a 

renewable energy portfolio standard of 15% of retail electricity sales in 2020, rising to 20% in 2035.

14

Table 5: Puerto Rico fossil-fired EGUs equal to or greater than 25 MW capacity

Plant name (location) Unit Fuel Unit type Capacity 

(MW)

AES (Guayama) 1 Coal ST 227 *

AES (Guayama) 2 Coal ST 227 *

Eco-electrica (Penuelas) CT1 Gas NGCC 568 *

Eco-electrica (Penuelas) CT2 Gas NGCC 568 *

PREPA Aguirre (Aguirre) AG1 No. 6 oil ST 450 *

PREPA Aguirre (Aguirre) AG2 No. 6 oil ST 450 *

PREPA Aguirre (Aguirre) CC1 distillate oil CC 296

PREPA Aguirre (Aguirre) CC2 distillate oil CC 296

PREPA Aguirre (Aguirre) T1-1 distillate oil CT 30

PREPA Aguirre (Aguirre) T1-2 distillate oil CT 30

PREPA Cambalache (Arecibo) C1 distillate oil CT 83

 

12 EIA, 2014. Puerto Rico Territory Energy Profile. Available at http://www.eia.gov/state/print.cfm?sid=RQ

13 In the June 2014 proposed rule, affected CTs are defined as those that combust natural gas for more than 90% of 

the CT’s heat input. Since available data indicate Puerto Rico’s CTs did not combust natural gas, those units have 

been excluded from the list of potentially affected units.

14 NCSU, 2014. Puerto Rico – Renewable Energy Portfolio Standard. Available at 

http://www.dsireusa.org/incentives/incentive.cfm?Incentive_Code=PR07R&ee=1.
TSD for Calculating Carbon Pollution Goals for Existing Power Plants in Territories and Areas of Indian Country

6

PREPA Cambalache (Arecibo) C2 distillate oil CT 83

PREPA Cambalache (Arecibo) C3 distillate oil CT 83

PREPA Daguao (Ceiba) T1-1 distillate oil CT 30

PREPA Daguao (Ceiba) T1-2 distillate oil CT 30

PREPA Jobos (Guayama) T1-1 distillate oil CT 227

PREPA Jobos (Guayama) T1-2 distillate oil CT 227

PREPA Mayaquez GT5 distillate oil CT 28

PREPA Mayaquez GT6 distillate oil CT 28

PREPA Mayaquez GT7 distillate oil CT 28

PREPA Mayaquez GT8 distillate oil CT 28

PREPA Palo Seco (Toa Baja) PS1 No. 6 oil ST 85 *

PREPA Palo Seco (Toa Baja) PS2 No. 6 oil ST 85 *

PREPA Palo Seco (Toa Baja) PS3 No. 6 oil ST 216 *

PREPA Palo Seco (Toa Baja) PS4 No. 6 oil ST 216 *

PREPA Palo Seco (Toa Baja) GT1-1 distillate oil CT 30

PREPA Palo Seco (Toa Baja) GT1-2 distillate oil CT 30

PREPA Palo Seco (Toa Baja) GT2-1 distillate oil CT 30

PREPA Palo Seco (Toa Baja) GT2-2 distillate oil CT 30

PREPA Palo Seco (Toa Baja) GT3-1 distillate oil CT 30

PREPA Palo Seco (Toa Baja) GT3-2 distillate oil CT 30

PREPA San Juan (San Juan) SJ7 No. 6 oil ST 100 *

PREPA San Juan (San Juan) SJ8 No. 6 oil ST 100 *

PREPA San Juan (San Juan) SJ9 No. 6 oil ST 100 *

PREPA San Juan (San Juan) SJ10 No. 6 oil ST 100 *

PREPA San Juan (San Juan) CC5 distillate oil CC 232

PREPA San Juan (San Juan) CC6 distillate oil CC 232

PREPA South Coast (Guiyanilla) SC3 No. 6 oil ST 85 *

PREPA South Coast (Guiyanilla) SC4 No. 6 oil ST 85 *

PREPA South Coast (Guiyanilla) SC5 No. 6 oil ST 410 *

PREPA South Coast (Guiyanilla) SC6 No. 6 oil ST 410 *

PREPA South Coast (Guiyanilla) GT1 distillate oil CT 45

PREPA South Coast (Guiyanilla) GT2 distillate oil CT 45

PREPA Vega Baja GT1-1 distillate oil CT 30

PREPA Vega Baja GT1-2 distillate oil CT 30

PREPA Yabucoa (Humacao) GT1-1 distillate oil CT 30

PREPA Yabucoa (Humacao) GT1-2 distillate oil CT 30

Note: EGUs with asterisks were included in the goal calculation for Puerto Rico

The U.S. Virgin Islands Water and Power Authority (VIWAPA), an independent government agency, 

manages the territory’s two separate electricity grids. There are several fossil-fired EGUs in the U.S. Virgin 

Islands, but most are less than 25 MW nameplate capacity. The Agency found information about 3 fossilfired EGUs equal to or greater than 25 MW (see Table 6). Excluding the oil-fired combustion turbine (CT)

EGU,

15 there is 1 coal-fired ST EGU that has not operated in more than 20 years and 1 oil-fired ST EGU that 

 

15 In the June 2014 proposed rule, affected CTs are defined as those that combust natural gas for more than 90% of 

the CT’s heat input. Since available data indicate the U.S. Virgin Island’s CT did not combust natural gas, that unit has 

been excluded from the list of potentially affected units.
TSD for Calculating Carbon Pollution Goals for Existing Power Plants in Territories and Areas of Indian Country

7

has not operated since 2011. Because there are no 2012 data for the analysis and because there is no 

indication that VIWAPA will return these units to operation, the analysis does not include a goal 

calculation for the U.S. Virgin Islands.

Table 6: Virgin Island fossil-fired EGUs equal to or greater than 25 MW capacity

Plant name (location) Unit Fuel Unit type Capacity 

(MW)

Krum Bay 13 No. 6 oil ST 35

Krum Bay 23 Distillate oil CT 39

St. Croix Renaissance 10 Coal ST 25

Data 

Potentially-affected EGUs in the U.S. territories do not report comprehensive information to the Agency

or the Energy Information Administration (EIA). Therefore, the Agency compiled data from a variety of 

sources, including:

 EPA’s Greenhouse Gas Reporting Program16

 Puerto Rico Electric Power Authority (PREPA)

 U.S. Virgin Islands Power and Water Authority (VIWAPA)

 Guam Power Authority (GPA)

 EIA’s form EIA-861

The territory goals are described as a CO2 emission rate (lb of CO2 per MWh of net electricity generation). 

However, the Agency did not have comprehensive unit-level data available on both CO2 emissions and net 

electricity generation. For Guam, the Agency received unit-level net generation and fuel consumption 

data from GPA. For Puerto Rico, the Agency had unit-level CO2 emission data reported by the power 

companies to the EPA’s Greenhouse Gas Reporting Program. Therefore, two different methodologies 

were used to calculate CO2 emissions (Guam) and net electricity generation (Puerto Rico).

For Guam, GPA provided information about unit-level net generation and fuel consumption. The Agency 

used the information to calculate unit-level CO2 emissions using the following formula:

CO22012 = OIL2012 × EF

Where:

CO22012 is the 2012 annual CO2 emissions in metric tons;

OIL2012 is the 2012 annual oil consumption in gallons; and

EF is an emission factor of 0.01127 metric tons of CO2/gallon of No. 6 oil.17

For Puerto Rico, CO2 emission data for 2012 were available at the unit level, but information was not 

available for unit-level net electricity generation in 2012. The Agency estimated 2012 net electricity 

 

16 Information about EPA’s Greenhouse Gas Reporting Program is available on the program’s website at 

http://ghgdata.epa.gov/ghgp.

17 Emission factors from 40CFR Part 98 Subpart C, Table C-1. Available at http://www.ecfr.gov/cgi-bin/textidx?SID=0769576af3d3e7d0e7c4556a2611dc4c&node=ap40.21.98_138.1&rgn=div9. 
TSD for Calculating Carbon Pollution Goals for Existing Power Plants in Territories and Areas of Indian Country

8

generation by multiplying each unit’s ratio of maximum net electricity generation to maximum CO2

emissions by the unit’s reported CO2 emissions in 2012. The calculation is:

MWh2012 = (

MWhmax

CO2max

) × CO22012

Where:

MWh2012 is the annual net electricity output produced by the EGU in MWh;

MWhmax is the maximum potential annual net electricity output produced by the EGU in MWh –

calculated as nameplate capacity in MW X 8,784 hours18 X a net:gross conversion factor (see Table 

7);

CO22012 is the 2012 annual CO2 emissions in metric tons reported to the EPA’s Greenhouse Gas 

Reporting Program; and

CO2max is the maximum potential CO2 emissions in metric tons – calculated as:

CO2max =

(Fc × Uf × MWCO2 × HImax )

2205 (

lb

metric ton)

Where:

Fc is a carbon-based F-factor in standard cubic feet (scf) CO2/mmBtu (see Table 8);

Uf is a conversion factor equal to 1/385 scf CO2/lb-mole at 14.7 psia and 68° F;

MWCO2 is the molecular weight of CO2, 44 lb/lb-mol; and

HImax is the maximum potential annual heat input in mmBtu – calculated as:

HImax = C ×

1

ηpm

× 8,784h × K

Where:

C is the nameplate capacity of the unit in MW;

ηpm is the electricity generating efficiency of the prime mover-fuel combination in 

percent19 – calculated as 3.412 mmBtu/MWh20 ÷ heat rate in mmBtu/MWh for 

the prime mover-fuel combination (see Table 9)

21; and

K is a constant equal to 3.412 mmBtu/MWh, the energy value of 1 MWh.

 

18 The number of possible operating hours in 2012. 

19 For information about calculating power plant efficiency, see EIA, Frequently Asked Questions: What is the 

efficiency of different types of power plants? Available at http://www.eia.gov/tools/faqs/faq.cfm?id=107&t=3.

20 One MWh of electricity is equal to 3.412 mmBtu of energy. 

21 Heat rates are based on 2012 data from EIA, Electric Power Annual, Table 8.2: Average tested heat rates by prime 

mover and energy source 2007-2012. Available at http://www.eia.gov/electricity/annual/html/epa_08_02.html. 
TSD for Calculating Carbon Pollution Goals for Existing Power Plants in Territories and Areas of Indian Country

9

Table 7: Net:gross electricity generation factor (2012)

EGU type Net:gross 

ratio

Coal ST .9360

Oil ST .9352

Natural gas CC .9728

Table 8: Carbon-based F-factors (scf/mmBtu)

Fuel type Fc

Coal (bituminous) 1800

Oil 1420

Natural gas 1040

Source: 40CFR Part 75 App. G §2.3

Table 9: Electric generating efficiency by prime mover type and fuel (2012)

EGU type Heat rate 

(mmBtu/MWh)

Coal ST 10.107

Oil ST 10.359

Natural gas CC 7.615

Source: EIA, Electric Power Annual, Table 8.2: Average tested heat rates by prime mover and energy source 2007-

2012. Available at http://www.eia.gov/electricity/annual/html/epa_08_02.html. 

The unit-level data for Guam and Puerto Rico are in the supporting technical files to this TSD [see Excel 

workbook titled “Appendix 1, 2, & 3 – Tribal and Territory Unit-level Inventory, Goal Data and 

Computation, and Cost Calculations”].

For renewable energy, the available information indicate that generation from utility-scale, gridconnected renewable energy on Guam and Puerto Rico in 2012 was limited to hydroelectric energy in 

Puerto Rico (see Table 10). The total estimated annual technical potential (MWh) for solar PV and wind in 

Puerto Rico were developed using datasets for 40 km solar22 and 70m wind23 and methodologies generally 

consistent with the NREL report, “U.S. Renewable Energy Technical Potentials: A GIS-Based Analysis.”24

More specific information related to the methodologies for developing the datasets are available for 40 

km solar25 and 70m wind.

26 Other data sources include:

 

22 National Renewable Energy Lab (NREL), 2003. Caribbean 40km Tilt Equals Latitude. Available at 

www.nrel.gov/gis/data/GIS_Data_Technology_Specific/International/Solar/Low_Resolution/Caribbean_40km_Tilt

_Equals_Latitude.zip. 

23 National Renewable Energy Lab (NREL), 2009. Annual average modeled wind speed (m/s) for Puerto Rico and the 

Virgin Islands at a 70 meter hub height. Available at http://en.openei.org/datasets/dataset/annual-averagemodeled-wind-speed-m-s-for-puerto-rico-and-the-virgin-islands-at-a-70-meter-hub-hei. 

24 Lopez, et al, 2012. U.S. Renewable Energy Technical Potentials: A GIS-Based Analysis. Available at 

http://www.nrel.gov/docs/fy12osti/51946.pdf. 

25 Campbell-Howe & Wilkins-Crowder (eds), 1999. Proceedings of the Solar 99 Conference. Available at 

http://www.nrel.gov/gis/pdfs/proceedings_solar99.pdf. 

26 Elliot & Schwartz, 2005. Development and Validation of High-Resolution State Wind Resource Maps for the United 

States. Available at http://www.nrel.gov/docs/fy05osti/38127.pdf. 
TSD for Calculating Carbon Pollution Goals for Existing Power Plants in Territories and Areas of Indian Country

10

 Net generation by utility: Form EIA-86127

 Existing generation: EIA territorial profiles28

Table 10: Renewable energy net generation (MWh)

Territory Renewables 2011

(MWh)

2012

(MWh)

Guam Hydro 0 0

Non-hydro 0 NA

Puerto Rico Hydro 149,000 148,000

Non-hydro 0 NA

Source: EIA, International Energy Statistics, Total Renewable Electricity Net Generation.

Data required for the calculation of building block 4 goals for territories and their sources are:

 2012 electricity sales (MWh): Form EIA-86129

 2012 energy efficiency incremental effects – total (MWh): Form EIA-86130

These data are inputs to the supporting technical files to this TSD:

 Option 1A: Building block 4 proposed goal based on each tribe/territory ramping up to 1.5% 

incremental savings with costs calculated using a 3% discount rate;

 Option 1B: Building block 4 proposed goal based on each tribe/territory ramping up to 1.5% 

incremental savings with costs calculated using a 7% discount rate;

 Option 2A: Building block 4 alternative goal based on each tribe/territory ramping up to 1.0% 

incremental savings with costs calculated using a 3% discount rate; and

 Option 2B: Building block 4 alternative goal based on each tribe/territory ramping up to 1.0% 

incremental savings with costs calculated using a 7% discount rate.

Table 11 summarizes data on 2012 electricity sales for the territories. None of the territories reported 

energy efficiency data on their Form EIA-861 submittals for 2012. Unlike the tribes and states, electricity 

sales projections are not available from the 2013 AEO reference case. EPA is not aware of another source 

for this information and, thus, is holding sales constant at their 2012 levels through the analysis period.

Table 11: 2012 total electricity sales for territories

Territory Utility Number Utility Name Total Sales

(MWh)

Guam 40428 Guam Power Authority 1,563,475

Puerto Rico 15497 Puerto Rico Electric Power Authority 18,150,330

 

27 Available at http://www.eia.gov/electricity/data/eia861/ (see "operational data" workbook)

28 Available at - http://www.eia.gov/state/analysis.cfm?sid=GQ and http://www.eia.gov/state/analysis.cfm?sid=RQ

29 Available at http://www.eia.gov/electricity/data/eia861/ (see “retail sales”).

30 Available at http://www.eia.gov/electricity/data/eia861/ (see “dsm”).
TSD for Calculating Carbon Pollution Goals for Existing Power Plants in Territories and Areas of Indian Country

11

BSER factors informing territories’ emission rate goals 

As discussed in the section on BSER factors informing tribal lands’ emission rate goals, the methodology 

for calculating emission rate goals generally applies the same approach to determining BSER as described 

in the Goal Computation TSD from the June 2014 proposed rule. 

Building block 1 – heat rate improvement at coal-fired power plants

Using the data discussed above, the Agency applied a 6% heat rate improvement to the coal-fired EGUs 

in Puerto Rico. The Agency assumes that a 6% heat rate improvement at the facility with the coal-fired 

EGUs will directly translate to a 6% reduction in the net CO2 emission rate. To calculate the alternative 

goal, the Agency applied a 4% heat rate improvement to the EGUs. The results from building block 1 are 

presented in Table 12.

Table 12: Adjusted average coal CO2 emission rate for coal-fired EGUs

Territory 6% HRI

Coal CO2 rate 

(lbs/MWh)

4% HRI

Coal CO2 rate 

(lbs/MWh)

Puerto Rico 2,083 2,127

Building block 2 – redispatch to lower-emitting NGCC EGUs

In 2012, Puerto Rico had a one facility with two NGCC EGUs. Based on the Agency’s calculations described 

above, the facility operated at approximately a 37% capacity factor. The GHG Abatement Measures TSD31, 

suggests that the average availability of an NGCC is significantly greater than 70%. Because the NGCC EGUs 

in Puerto Rico use imported LNG, the Agency reviewed the capacity of the existing LNG port and gasifiers 

to ensure they would not constrain the ability of the EGUs to achieve a 70% capacity factor. Based on data 

available to the Agency, we believe the port has sufficient importing and processing capacity to supply 

LNG for the NGCCs to achieve a 70% capacity factor which offsets generation at both coal-fired ST EGUs 

and oil-fired ST EGUs.

Building block 3 – renewables

Because neither Guam nor Puerto Rico have utility-scale, grid-connected, non-hydroelectric renewable 

energy generation for 2012, the analysis of renewable energy using the proposed methodology from the 

June 2014 proposed rule resulted in no renewable energy targets, and, therefore, no change to the goals 

for these areas. 

The second co-proposal option includes an adjustment to the proposed methodology that changes the 

amount of renewable energy in 2017 to be consistent with the lowest amount among the 50 states in 

2012, which is 0.37% of the 2012 total electricity generation. EPA then applies the 9% annual growth 

factor through 2029. The 9% annual growth factor is based on Hawaii’s historical growth in renewable 

energy generation between 2002 and 2012. 

For Puerto Rico’s renewable energy target based on the alternative approach, the Agency used estimates 

provided by DOE for wind and utility-scale solar PV (urban and rural) from available wind and solar 

resource data for the region. The wind resource data used are 70m hub height wind speed estimates 

 

31 See footnote 6.
TSD for Calculating Carbon Pollution Goals for Existing Power Plants in Territories and Areas of Indian Country

12

modeled by AWS Truepower and NREL in 2008. The solar resource data used was produced by the NREL 

Climatological Solar Radiation model in 2007. 

Consistent with the June 2014 proposed rule, the Agency also includes renewable energy targets for 

Puerto Rico with the inclusion of 2012 hydroelectric generation. These data are presented in the technical 

files to this TSD:

 Data file – Supplemental Proposed RE Method; and

 Data file – Supplemental Alternative RE Approach.

Building block 4 – energy efficiency

The analysis of energy efficiency for building block 4 used the proposed methodology from the June 2014 

proposed rule.
TSD for Calculating Carbon Pollution Goals for Existing Power Plants in Territories and Areas of Indian Country

13

APPENDIX 1 – TRIBAL AND TERRITORY UNIT-LEVEL INVENTORY 

See “App 1 – Info”, “App 1 – Guam”, “App 1 – PR”, and “App 1 – Tribes” worksheets in Excel workbook 

titled “Appendix 1, 2, & 3 – Tribal and Territory Unit-level Inventory, Goal Data and Computation, and Cost 

Calculations”

APPENDIX 2 – GOAL DATA AND COMPUTATION 

See “App 2 – Goals option 1” and “App 2 – Goals option 2” worksheets in Excel workbook titled “Appendix 

1, 2, & 3 – Tribal and Territory Unit-level Inventory, Goal Data and Computation, and Cost Calculations”

APPENDIX 3 – COST CALCULATIONS 

See “App 3 – Cost info” and “App 3 – Cost analysis” worksheets in Excel workbook titled “Appendix 1, 2, 

& 3 – Tribal and Territory Unit-level Inventory, Goal Data and Computation, and Cost Calculations”

 
TSD for Calculating Carbon Pollution Goals for Existing Power Plants in Territories and Areas of Indian Country

14

APPENDIX 4 – SUMMARY OF TRIBAL AND TERRITORY GOALS UNDER THE PROPOSED 

EXISTING SOURCE PERFORMANCE STANDARD 

Proposed and alternate goals with approach A 

The proposed goals and alternative goals are based on no non-hydro, grid-connected renewable energy 

in 2012.

Figure 4 - 1: Proposed goals (option 1) and alternate goals (option 2) with approach A for building block 3

Territory or 

tribal lands

Option 1

Interim goal 

(2020-2029)

Option 1

Final goal

(2030 and after)

Option 2

Interim goal 

(2020-2024)

Option 2

Final goal

(2025 and after)

Guam 1,733 1,586 1,854 1,794

Puerto Rico 1,470 1,413 1,542 1,521

Fort Mojave 856 855 857 857

Navajo 1,991 1,989 2,035 2,034

Ute 2,000 1,988 2,052 2,048

Co-proposed and alternate goals with approach B 

The co-proposed goals and alternate co-proposed goals are based on the lowest amount of renewable 

energy among the 50 states in 2012 – 0.37%.

Figure 4 - 2: Co-proposed and alternate co-proposed goals with approach B for building block 3

Territory or 

tribal lands

Option 1

Interim goal 

(2020-2029)

Option 1

Final goal

(2030 and after)

Option 2

Interim goal 

(2020-2024)

Option 2

Final goal

(2025 and after)

Guam 1,708 1,556 1,831 1,768

Puerto Rico 1,459 1,399 1,533 1,510

Alternative goals 

The alternative goals are based on the renewable energy technical potential.

Figure 4 - 3: Alternative goals using technical potential for building block 3

Territory or 

tribal lands

Interim goal 

(2020-2029)

Final goal 

(2030 and after)

Guam 1,733 1,586

Puerto Rico 1,452 1,397
TSD for Calculating Carbon Pollution Goals for Existing Power Plants in Territories and Areas of Indian Country

15

APPENDIX 5 – 2012 EMISSION RATE AND BUILDING BLOCK APPLICATION 

Proposed goals 

The proposed goals (option 1 approach A) are based on no non-hydro, grid-connected renewable energy 

in 2012.

Territory or 

tribal lands

2012 fossil rate Building block 

1

Building 

blocks 1 & 2

Building 

blocks 1, 2 & 3

Building 

blocks 1, 2, 

3, & 4

(final goal)

Guam 1,948 1,948 1,948 1,948 1,586

Puerto Rico 1,901 1,678 1,546 1,546 1,413

Fort Mojave 858 858 858 858 855

Navajo 2,121 1,993 1,993 1,993 1,989

Ute 2,145 2,016 2,016 2,016 1,988