Introduction
This guide to planning is intended to serve agricultural extension officers as a comprehensive tool for arriving at decisions concerning the suitability of locations for family-size biogas plants. The essential siting con-ditions capable of influencing the decision for or against a biogas plant are covered (cf. figure 2.1 for a summary survey). The detailed planning outline (table 2.1) has a ´'data" column for entering the pertinent information and a "rating" column for noting the results of evaluation.Evaluation criteria
+ Siting condition favorable
o Siting condition unfavorable, but
a) compensable by project activities,
b) not serious enough to cause ultimate failure,
- Siting condition not satisfied / not satisfiable
Information on how to obtain and evaluate the individual data can be found in the corresponding chapters of this manual by following the pointers provided in the "reference" column. .
Despite its detailed nature, this planning guide is, as intended, nothing more than a framework within which the extension officer should proceed to conduct a careful investigation and give due consideration, however subjectively, to the individual conditions in order to arrive at a locally practical solution. By no means is this planning guide intended to relieve the agricultural extension officer of his responsibility to thoroughly familiarize himself with the on the-spot situation and to judge the overall value of a given location on the basis of the knowledge thus gained.
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| Fig. 2.1: Biogas planning modules (Source: OEKOTOP) |
Table 2.1: Detailed planning guide for biogas plants
| Item | Reference | Data | Rating |
| 0. Initial situation | |||
| Addresses/project characterization | |||
| Plant acronym: | ....... | ||
| Address of operator/customer: | ....... | ||
| Place/region/counky: | ....... | ||
| Indigenous proj. org./executing org.: | ....... | ||
| Extension officer/advisor: | ....... | ||
| General user data | |||
| Household structure and no. of persons: | ....... | ||
| User's economic situation: | ....... | ||
| Animals: kind, quantity, housing: | ....... | ||
| Crops: types, areas, manner of cultivation: | ....... | ||
| Non-agricultural activity: | ....... | ||
| Household/farmincome: | ....... | ||
| Cultural and social characteristics of user: | ....... | ||
| Problems leading to the "biogas" approach | |||
| Energy-supply bottlenecks: | ....... | ||
| Workload for prior source of energy: | ....... | ||
| Poor soil structure/yields: | ....... | ||
| Erosion/deforestation: | ....... | ||
| Poor hygiene . . ., other factors: | ....... | ||
| Objectives of the measure "biogas plant" | |||
| User interests: | ....... | ||
| Project interests: | ....... | ||
| Other interests: | ....... | ||
| 1. Natural / Agricultural conditions | |||
| Natural conditions | Chapter 3.1 | ||
| Mean annual temperature: | ....... | ||
| Seasonal fluctuations: | ....... | ||
| Diurnal variation: | ....... | ||
| Rating: | ....... | + o - | |
| Subsoil | Chapter 3.1 | ||
| Type of soil: | ....... | ||
| Groundwater table, potable water catchment area: | ....... | ||
| Rating: | + o - | ||
| Ratings: + Siting condition favorable | |||
| o Siting condition unfavorable but compensable and/or not too serious | |||
| - Siting condition not satisfied / not satisfable | |||
| Water conditions | Chapter 3.1 | ||
| Climate zone: | Table 3.1 | ....... | |
| Annual precipitation: | ....... | ||
| Dry season (months): | ....... | ||
| Distance to source of water: | ....... | ||
| Rating: | + o - | ||
| Livestock inventory, useful for biogas | Chapter 3.2/3.3 | ||
| production | ....... | ||
| Animals: kind and quantity: | ....... | ||
| Type and purpose of housing: | ....... | ||
| Use of dung: | ....... | ||
| Persons responsible for animals: | ....... | ||
| Rating: | |||
| Vegetable waste, useful for biogas production | Chapter 3.2/3.3 | ||
| Types and quantities: | ....... | ||
| Prior use: | ....... | ||
| Rating: | + o - | ||
| Fertilization | Chapter 3.4 | ||
| Customary types and quantities of fertilizer/areas fertilized: | ....... | ||
| Organic fertilizer familiar/in use: | ....... | ||
| Rating: | + o - | ||
| Potential sites for biogas plant | Chapter 3.3 | ||
| Combined stabling/biogas plant possible: | ....... | ||
| Distance between biogas plant and livestock housing: | ....... | ||
| Distance between biogas plant and place of gas consumption: | ....... | ||
| Rating: | + o - | ||
| Overall rating 4 | + o - | ||
| 2. Balancing the energy demand with the biogas production | Chapter 4 | ||
| Prior energy supply | Chapter 4 | ||
| Uses, source of energy, consumption: | ....... | ||
| Anticipated biogas demand (kWh/day or l/d) | Chapter 5.5.3 | ||
| for cooking: | Table 5.17 | ....... | |
| for lighting: | Table 5.20 | ....... | |
| for cooling: | Table 5.22 | ....... | |
| for engines: | Chapter 5.5.4 | ....... | |
| Total gas demand | Chapter 4.1 | ||
| a) percentage that must be provided by the biogas plant: | ....... | ||
| b) desired demand coverage: | ....... | ||
| Ratings: + Siting condition favorable | |||
| o Siting condition unfavorable but compensable and/or not too serious | |||
| - Siting condition not satisfied / not satisfiable | |||
| Available biomass (kg/d) and potential gas production (l/d) | Chapter 3/4 | ||
| from animal husbandry | Table 3.2 | ....... | |
| ...pigs: | Table 3.5 | ....... | |
| ...poultry: | Table 4.3 | ....... | |
| ...cattle: | Figure 5.2 | ....... | |
| Night soil | Table 3.2 | ....... | |
| Vegetable waste (quantities and potential gas yield) | Table 3.3 | ||
| 1............................... | Table 3.5 | ....... | |
| 2............................... | |||
| Totals: biomass and potential gas production | Chapter 4.2 | ||
| a) easy to procure: | ....... | ||
| b) less easy to procure: | ....... | ||
| Balancing | Chapter 4.4 | ||
| Gas production clearly greater than gas demand = positive rating (+) | ....... | ||
| Gas demand larger than gas production | |||
| = negative rating (-); but review of results in order regarding: | ....... | ||
| a) possible reduction of gas demand by the following measures | ....... | ||
| b) possible increase in biogas production by the following measures | ....... | ||
| If the measures take hold: | ....... | ||
| = qualified positive rating for the plant location (o) | |||
| If the measures do not take hold: | ....... | ||
| = site rating remains negative (-) | |||
| Overall rating 2 | + o - | ||
| 3. Plant Design and Construction | Chapter 5 | ||
| Selection of plant design | Chapter 5.3 | ||
| Locally customary type of plant: | ....... | ||
| Arguments in favor of floating-drum plant: | Chapter 5.3.1 | ....... | |
| Arguments in favor of fixed-dome plant: | Chapter 5.3.2 | ....... | |
| Arguments in favor of other plant(s): | Chapter 5.3.3 | ....... | |
| Type of plant chosen: | ....... | ||
| Selection of site | ....... | ||
| Ratings: + Siting condition favorable | |||
| o Siting condition unfavorable but compensable and/or not too serious | |||
| - Siting condition not satisfied / not satisfiable | |||
| Availability of building materials | |||
| Bricks/blocks/stone: | ....... | ||
| Cement: | ....... | ||
| Metal: | ....... | ||
| Sand: | ....... | ||
| Piping/fittings: | ....... | ||
| Miscellaneous: | ....... | ||
| Availability of gas appliances | |||
| Cookers: | ....... | ||
| Lamps: | ....... | ||
| ........................................... | ....... | ||
| ........................................... | ....... | ||
| Overall rating 3 | + o - | ||
| 4. Plant operation / maintenance / repair | Chapter 7 | ||
| Assessment of plant operation | Chapter 7.1 | ||
| Incidental work: | Chapter 7.2 | ....... | |
| Work expenditure in h: | ....... | ||
| Persons responsible: | ....... | ||
| Rating with regard to anticipated implementation: | + o - | ||
| Plant maintenance | Chapter 7.3 | ||
| Maintenance-intensive components: | ....... | ||
| Maintenance work by user: | Table 7.2 | ....... | |
| Maintenance work by external assistance: | ....... | ||
| Rating with regard to anticipated implementation: | + o - | ||
| Plant repair | Chapter 7.4 | ||
| Components liable to need repair: | ....... | ||
| Repairs that can be made by the user: | ....... | ||
| Repairs requiring external assistance: | ....... | ||
| Requisite materials and spare parts: | |||
| Rating with regard to expected | |||
| repair services: | + o - | ||
| Overall rating 4 | + o - | ||
| 5. Economic analysis | Chapter 8 | ||
| Time-expenditure accounting | Chapter 8.2 | ||
| Time saved with biogas plant | Table 8.1 | ....... | |
| Time lost due to biogas plant | ....... | ||
| Rating: | |||
| Ratings: + Siting condition favorable | |||
| o Siting condition unfavorable but compensable and/or not too serious | |||
| - Siting condition not satisfied / not satisfiable | |||
| Microeconomic analysis | Chapter 8.3 | ||
| Initial investment: | Table 8.2 | ....... | |
| Cost of operation/maintenance/repair: | ....... | ||
| Return on investment:energy, fertilizer, otherwise: | ....... | ||
| Payback time (static): | Table 8.3 | ....... | |
| Productiveness (static): | ....... | ||
| Rating: | + o - | ||
| Quality factors, useful socioeconomic effects and costs | Chapter 8.5 | ||
| Useful effects: hygiene, autonomous energy, better | |||
| lighting, better working conditions, prestige: | ....... | ||
| Drawbacks: need to handle night soil, negative social impact: | ....... | ||
| Rating: | + o - | ||
| Overall rating 5 | + o - | ||
| 6. Social acceptance and potential for dissemination | Chapter 9 | ||
| Anticipated acceptance | Chapter 9.1 | ||
| Participation in planning and construction: | ....... | ||
| Integration into agricultural setting: | ....... | ||
| Integration into household: . | ....... | ||
| Sociocultural acceptance: | ....... | ||
| Rating: | ....... | ||
| Establishing a dessemination strategy | Chapter 9.2 | ||
| Conditions for and chances of the professional craftsman approach: | ....... | + o - | |
| Conditions for and chances of the self-help oriented approach: | ....... | + o - | |
| General conditions for dissemination | |||
| Project-executing organization and its staffing: | Chapter 9.3 | ....... | |
| Organizational structure: | ....... | ||
| interest and prior experience in biogas technology: | ....... | ||
| Regional infrastructure for transportation and communication: | ....... | ||
| material procurement: | ....... | ||
| Craftsman involvement, i.e. | Chapter 9.4 | ||
| which activities: | ....... | ||
| minimum qualifications: | ....... | ||
| tools and machines: | ....... | ||
| Training for engineers, craftsman and users: | Chapter 9.5 | ....... | |
| Ratings: + Siting condition favorable | |||
| o Siting condition unfavorable but compensable and/or not too serious | |||
| - Siting condition not satisfied/not satisfiable | |||
| Proprietary capital, subsidy/credit requirement | |||
| on the part of | Chapter 9.6 | ||
| user: | ....... | ||
| craftsmen: | ....... | ||
| Rating: | ....... | + o - | |
| Overall rating 6 | ....... | + o - | |
| 7. Summarization | |||
| Siting conditions | No. | Rating | |
| Natural/agricultural conditions | 1 | + o - | |
| Balancing the energy demand and the biogas production | 2 | + o - | |
| Plant design and construction | 3 | + o - | |
| Plant operation/maintenance/repair | 4 | + o - | |
| Economic analysis | 5 | + o - | |
| Social acceptance and potential for dissemination | 6 | + o - | |
| Overall rating of siting conditions | + o - | ||
| Ratings: + Siting condition favorable | |||
| o Siting condition unfavorable but compensable and/or not too serious | |||
| - Siting condition not satisfied / not satisfiable |
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.
