Development of Pond Operations Cost Factors - 

Plant Capacity (MW) Factor

This Excel file contains the following worksheet:

Plant MW Factor 

This Excel workbook documents EPA's analysis to calculate a factor to estimate unitized pond costs for different sized 

plants (relative to a 500 MW plant).

Contains data from EPA's 1985 study, Full-Scale Field Evaluation of Waste Disposal 

from Coal-fired Electric Generating Plants (Table 9 - Generic Annual Cost Esitmates 

for FGC Waste Disposal (Late 1982 Dollars)), for fly ash and bottom ash wet sluicing 

transportation. Using these values, EPA calculated a relative factor for estimating 

unitized costs for different sized plants. EPA calculated the factors relative to a 500 MW 

plant because the pond operation costs from EPA's/TVA's 1981 study, Economics of Ash 

Disposal at Coal-fired Power Plants, represented a 500 MW plant. EPA used the 

calculated factors to generate a plot and corresponding equation for altering unitized 

costs based on plant size (in MW).
sts for different sized 

of Waste Disposal 

ual Cost Esitmates 

m ash wet sluicing 

for estimating 

relative to a 500 MW 

Economics of Ash 

 EPA used the 

 altering unitized 
Type of Cost Plant Size (MW)

Min Range 

(1982 $/ton)

Fly Ash - Transport (Wet Sluicing) 250 4.2

Fly Ash - Transport (Wet Sluicing) 500 3.2

Fly Ash - Transport (Wet Sluicing) 1000 2.5

Fly Ash - Transport (Wet Sluicing) 2000 2

Fly Ash - Placement/Disposal (Unlined Pond) 250 11.5

Fly Ash - Placement/Disposal (Unlined Pond) 500 9.1

Fly Ash - Placement/Disposal (Unlined Pond) 1000 7.2

Fly Ash - Placement/Disposal (Unlined Pond) 2000 5.7

Bottom Ash - Transport (Wet Sluicing) 250 9.2

Bottom Ash - Transport (Wet Sluicing) 500 7.3

Bottom Ash - Transport (Wet Sluicing) 1000 5.6

Bottom Ash - Transport (Wet Sluicing) 2000 4.3

Bottom Ash - Placement/Disposal (Unlined Pond) 250 9.2

Bottom Ash - Placement/Disposal (Unlined Pond) 500 7.9

Bottom Ash - Placement/Disposal (Unlined Pond) 1000 6.5

Bottom Ash - Placement/Disposal (Unlined Pond) 2000 5.4

Type of Cost Plant Size (MW)

Min Range 

(1982 $/ton)

Fly Ash (Total) 250 15.7

Fly Ash (Total) 500 12.3

Fly Ash (Total) 1000 9.7

Fly Ash (Total) 2000 7.7

Bottom Ash (Total) 250 18.4

Bottom Ash (Total) 500 15.2

Bottom Ash (Total) 1000 12.1

Bottom Ash (Total) 2000 9.7

Fly Ash

Bottom Ash

Data from EPA's 1985 study, Full-Scale Field Evaluation of Waste Disposal from Coal-fired Electric Generating Pl

Table 9 - Generic Annual Cost Esitmates for FGC Waste Disposal (Late 1982 Dollars) for the fly ash wet sluicing and 

placement/disposal modules and the bottom ash wet sluicing and placement/disposal modules.

EPA calculated the total dollar per ton values for both fly and bottom ash numbers (Wet Sluicing + Unlined Pond) for 

plant sizes. EPA also calculated the average 1982 dollar per ton value for each plant size using the min and max cost r

and then calculated an average cost factor relative to the 500 MW plant (EPA used the 500 MW plant because the 19

EPA/TVA pond cost data is based on a 500 MW plant). 

Bottom Ash

Fly Ash
Type of Cost Plant Size (MW)

Average Cost Factors 

Relative to 500 MW 

Plant

Combined Ash ($/ton) 250 1.245

Combined Ash ($/ton) 500 1.000

Combined Ash ($/ton) 1000 0.797

Combined Ash ($/ton) 2000 0.632

Using these calculated average cost factors and the plant size, EPA generated the following plot:

Plant MW Factor = 7.569(MW)-0.32

EPA determined that the power trend line generated the best r-squared value; therefore, used this equation in the pond 

to calculate plant-specific unitized cost values based on specific plant size (in MW). See the equation below:

After calculating the total fly ash- and bottom ash-specific average cost factor values, EPA combined the two by avera

the bottom ash factor, for each plant size. The results are presented below.

y = 7.5696x-0.326

R2 = 0.9998

0.000

0.200

0.400

0.600

0.800

1.000

1.200

1.400

0 500 1000 1500 2000 2500

A

vg C

ost Factors Relative to 50

0

M

W

Plant

Plant MW

Plot Average Cost Factor Versus Plant 

MW

Plot Average Cost Factor

versus Plant MW

Power (Plot Average

Cost Factor versus Plant

MW)
Max Range 

(1982 $/ton)

7.6

5.9

4.7

3.7

21.3

16.8

13.5

10.5

17.1

13.5

10.3

7.9

17.1

14.6

12.1

10

Max Range 

(1982 $/ton)

Average 

(1982 $/ton)

Average Cost Factor 

Relative to 500 MW 

Plant

28.9 22.3 1.274

22.7 17.5 1.000

18.2 13.95 0.797

14.2 10.95 0.626

34.2 26.3 1.215

28.1 21.65 1.000

22.4 17.25 0.797

17.9 13.8 0.637

-fired Electric Generating Plants, 

or the fly ash wet sluicing and 

Sluicing + Unlined Pond) for all 

 using the min and max cost ranges 

00 MW plant because the 1981 
used this equation in the pond operation costs methodology 

the equation below:

PA combined the two by averaging the fly ash factor with