Table 9 NPV, IRR and payback value for the scenario 1 and 2

A) Selling only electricity with no cow

NPV

$− 14,277.46

$− 8,459.59

$− 8,903.23

% IRR

N/A

N/A

N/A

PB

N/A

27.69

13.52

B) Selling electricity and fertilizers with no cow

NPV

$− 14,098.56

$− 8,101.80

$− 8,366.55

% IRR

N/A

N/A

N/A

PB

− 11.74

24.55

12.78

C) Selling electricity with cow

NPV

$− 12,655.89

$− 5,216.45

$− 4,038.52

% IRR

N/A

− 16%

− 6%

PB

− 16.23

12.83

8.86

D) Selling electricity and fertilizers with cow

NPV

$− 12,476.99

$− 4,858.66

$− 3,501.84

% IRR

N/A

− 14%

− 5%

PB

− 17.04

12.12

8.54

E) Selling electricity and fertilizers with cow co-digestion HF + cow dung

NPV

$− 11,368.41

$− 3,724.19

$− 2,341.47

% IRR

N/A

− 9%

− 3%

PB

$− 24.65

10.29

7.91

F) Selling electricity and fertilizers with cow co-digestion grass

NPV

$135.02

$7,679.55

$8,962.58

% IRR

0%

12%

9%

PB

6.79

4.10

4.61

G) Selling electricity with fertilizers with co-digestion CD/maize

NPV

$− 4,342.55

$3,182.97

$4,446.98

% IRR

0%

6%

5%

PB

13.47

5.37

5.53