Following assessment as in table 2.1, the biogas-plant site in question can only be regarded as
suitable, if most of the siting factors have a favorable (+) rating. This applies in particularly to item 2,
the positive energy balance, meaning that the potential biogas production must cover the gas
demand.
If the favorable and unfavorable ratings are fairly well balanced, the more decisive factors should be
re-evaluated to determine the extent to which supplementary measures could provide the missing
conditions for building and operating a biogas plant despite some reservations but without
injustifiable effort. Then, if the overall evaluation does not swing toward the positive side, the plant
should not be built. If the site is given a favorable rating, further planning hints can be taken from
the following checklist.
2.3 Checklist for building a biogas plant
1. Finishing the planning, i.e. site evaluation, determination of energy demand and biomass
supply/biogas yield, plant sizing, selection of plant design, how and where to use the
biogas, etc., ail in accordance with the above planning guide.
2. Stipulate the plant's location and elaborate a site plan, including all buildings, gas pipes,
gas appliances and fields to be fertilized with digested slurry.
3. Draft a technical drawing showing all plant components, i.e. mixing pit, connection to
stabling, inlet/outlet, digester, gasholder, gas pipes, slurry storage.
4. Preparation of material/personnel requirements list and procurement of materials needed
for the chosen plant:
- bricks/stones/blocks for walls and foundation
- sand, gravel
- cement/lime
- inlet/outlet pipes
- metal parts (sheet metal, angle irons, etc.)
- gas pipes and fittings
- paint and sealants
- gas appliances
- tools
- mason and helper
- unskilled labor
- workshops for metal (gasholder) and pipe installation.
5. Material/personnel assignment planning, i.e. procedural planning and execution of:
- excavation
- foundation slab
- digester masonry
- gasholder
- rendering and sealing the masonry
- mixing pit
- slurry storage pit
- drying out the plant
- installing the gas pipe
- acceptance inspection.
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