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NACAA, AAPCA, and ECOS Cosponsored 111(d) Webinar

Rate-to-Mass Conversion Questions

November 20, 2014

1. EPA has discussed the possibility of 111(d) applying to existing and new units. If 

EPA chooses to include new units in 111(d), will they increase the mass the state is 

allowed to emit by the amount the new unit would be allowed under NSPS? 

2. If an NGCC floor is established in the final rule, will EPA recalculate the mass goal 

for each state and communicate the result before the state plan deadline?

3. If the RE/EE fossil offset is established in the final rule, will the resulting numeric 

goal be less than in the original proposal?

4. The existing affected source approach from the rate-to-mass goal translation TSD 

produces a generation level (and CO2 mass) for GA that is 28% less than the 

generation (and CO2 mass) used to set the rate-based goal in the original rule 

proposal (see Table GA-1). How can a translated mass-based goal be equivalent to 

the rate-based goal if it does not use the same generation level?

Table GA-1. Final generation and CO2 emissions for selected goal calculation 

approaches

Goal approach/form 2030 

generation 

(MWh)

2030 CO2 

emissions 

(short tons)*

2030 CO2 

Rate 

(lbs/MWh)

Rate-to-mass Goal Translation

TSD – Tables 1 & 4;

Existing Affected Source

87,753,806 34,843,000 834

Original Goal Computation TSD 122,216,047 50,964,092 834

5. In the original proposal, EPA’s goal-setting equation adds incremental RE and EE to 

the 2012 baseline generation (in the denominator of the formula) but does not affect 

fossil generation or emissions. In the NODA, EPA proposed two different 

approaches for revising the goal-setting formula in which incremental RE and EE 

replace 2012 fossil generation. In the rate-to-mass goal translation TSD, incremental 

RE and EE generation replace historical fossil generation, which is similar to the 

NODA approaches. Is EPA’s rate-to-mass translation TSD approach intended to be 

equivalent to the rate-based limits established in the original proposal or is it intended 

to be equivalent to rate-based limits that would be determined using one or both of 

the approaches included in the NODA?

6. By using Table 1 of the rate-to-mass goal translation TSD, GA EPD calculates that

Georgia fossil generation in 2030 would shrink to 51 % of fossil generation in 2012. 

By comparison, data from the Annual Energy Outlook 2014 for the SERC-SE region
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project that 2030 fossil generation will be 123 % of 2012 generation. See Table GA2. How does EPA account for this very large disparity and is the fossil generation

projected by the TSD realistic?

Table GA-2. Comparison of Projected Fossil Generation – TSD versus AEO

2014

Projection Source 2012 fossil

generation

( 106 MWh)

2030 fossil generation

(106 MWh)

Ratio

(2030/2012)

Translation TSD Table 1,

(Existing Affected

Sources)*

78.6 40.2 0.51

AEO 2014 SERC-SE

Table 86**

(GA, AL, MS partial, FL

partial)

188.9 232.8 1.23

*2030 generation = historical fossil – Block 3 incremental – block 4 avoided

generation

**Calculated as sum of coal and natural gas generation

AEO reference: Released May 7, 2014, Electricity and Renewable Fuels Tables, 

Table 86, “Generation by Fuel Type" data

7. Could EPA choose a specific state and walk through their methodology for the two 

approaches to translating rate targets to mass targets, including identifying alternative 

inputs or data sources that states could use?

8. Would EPA look to translate a state’s rate-based target to a mass-based target in the 

event that the Agency imposes a federal implementation plan?

9. PJM’s analysis of its original interpretation of the rule found substantially a higher 

mass-based regional cap than that reflected in EPA’s TSD. Has EPA reviewed that 

analysis, and can the Agency explain the difference in the approach?

10. The proposed regulatory language for the 111(d) rule describes the process for 

converting a rate-based goal to a mass-based goal at 40 C.F.R. 60.5770. If a state 

plan incorporates exactly one of the methodologies and mass-based targets from 

EPA’s goal translation TSD, is the state’s mass-based goal presumptively

“equivalent” to the rate-based goal, as the regulations require? If not, what else 

would a state need to do to show it has an approvable mass-based goal?