Table 1 Input variables

Electrical power

kWe

500

[2]

Full load hours

h/a

8000

[56, 57]

Electrical efficiency

%

40

[58,59,60,61,62,63]

Digester volume

Cubic meter (cbm)

2570

[64]

Year of commissioning

Dry matter (DM) content

Year

2010

We assume that the plant is in its sixth year of operation

 DM of maize silage

%

34

[65, 66]

 DM of Elodea silage

%

7

[27]

 DM of Elodea-straw mix silage

%

30

[27]

Volatile solids maize silage

% of DM

95

[67]

Volatile solids Elodea silage

% of DM

80

[24], for fresh material not silage

Volatile solids Elodea-straw mix silage

% of DM

90

Estimation

Methane potential of maize silage

cbm/tonne fresh matter (FM)

110

[3, 62, 67,68,69,70]

Methane potential of Elodea silage

cbm/tonne FM

15

[27]

Methane potential of Elodea-straw mix

cbm/tonne FM

50

[27]

Feed-in-tariff for energy crops

EUR/kWhe

0.20

[71]; we used the RESA 2009 since the number of newly erected biogas plants reached a peak during 2009–2011

Feed-in-tariff for waste

EUR/kWhe

0.13

[71]; RESA 2009

Disposal cost for aquatic biomass (biogas plant gate fee)

EUR/tonne

30.00

Based on our survey

Disposal cost for digestate

EUR/tonne

5.00

[32]

Cost of maize silage (fresh matter)

EUR/tonne

40

[38, 63, 70, 72, 73]

Cost of straw (fresh matter)

EUR/tonne

81.41

[74]

Calorific (heating) value of methane

kWh/cbm

9.97

[75]

Utilization percentage of methane potential

%

98^a

96^b

97^c

Estimations based on [34]

Digestate/input ratio

%

85

[76,77,78,79]