Fig. 4.1: Balancing the energy demand with the biogas
production (Source: OEKOTOP)
4.1 Determining the Energy Demand
The energy demand of any given farm is equal to the sum of all present and future consumption
situations, i.e. cooking, lighting, cooling, power generation, etc. With deference to the general
orientation of this manual, emphasis is placed on determining the energy demand of a typical family
farm.
Experience shows that parallel calculations according to different methods can be useful in avoiding
errors in calculating the gas/ energy demand.
Table 4.1: Outline for determining biogas demand (Source: OEKOTOP)
Energy consumers
1. Gas for cooking (Chapter 5.5.3)
Number of persons
Number of meals
Present energy consumption
Present source of energy
Gas demand per person and meal (Table 5.17)
Gas demand per meal
Anticipated gas demand
Specific consumption rate of burner
Number of burners -
Duration of burner operation
Anticipated gas demand
Total anticipated cooking-gas demand
2. Lighting (Chapter 5.5.3)
Specific gas consumption per lamp (Table 5.20)
Number of lamps
Duration of lamp operation
Gas demand
3. Cooling (Chapter 5.5.3)
Specific gas consumption X 24 h (Table 5.22)
4. Engines (Chapter 5.5.4)
data
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Biogas demand
(l/d)
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30