Planning Guide for Biogas Plants

Overview

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-sized biogas plants. The detailed planning outline has a data column for entering the gathered information and a rating column for noting the results of evaluation.

Evaluation criteria are:

• + Siting condition are favorable

  o Siting condition are unfavorable, but

  a) compensable by project activities

  b) not serious enough to cause ultimate failure

  - Siting condition are not satisfactory

Despite its detailed nature, this planning guide is only 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 the 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.

Initial Situation

	Data	Rating
Addresses/project characterization Plant acronym: Address of operator/customer: Place/region/country: Indigenous proj. org./executing org.: Extension officer/advisor: General user data Household structure and number of persons: User's economic situation: Crops: types, areas, manner of cultivation: Non-agricultural activity: Household/farm income: 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 and other factors: Objectives of the measure "biogas plant" User interests: Project interests: Other interests:

Natural / Agricultural Conditions

	Data	Rating
Natural conditions Mean annual temperature: Seasonal fluctuations: Diurnal variation: Rating:		- o +
Subsoil Type of soil: Groundwater table, potable water catchment area: Rating:		- o +
Water conditions Climatic zone: Annual precipitation: Dry season (months): Distance to source of water: Rating:		- o +
Livestock inventory (useful for biogas production) Animals: kind and quantity: Type of stable: Use of dung: Persons responsible for animals: Rating:		- o +
Vegetable waste (useful for biogas production) Types and quantities: Prior use: Rating:		- o +
Fertilization Customary types and quantities of fertilizer/areas fertilized: Organic fertilizer familiar/in use: Rating:		- o +
Potential sites for biogas plant Combined stable/biogas plant possible: Distance between biogas plant and livestock stable: Distance between biogas plant and place of gas consumption: Rating:		- o +
Overall rating 1		- o +

Balancing the Energy Demand with the Biogas Production

	Data	Rating
Prior energy supply Uses, source of energy, consumption: Anticipated biogas demand (kwh/day or l/d) for cooking: for lighting: for cooling: for engines: Total gas demand a) percentage that must be provided by the biogas plant: b) desired demand coverage: Available biomass (kg/d) and potential gas production (l/d) from animal husbandry pigs: poultry: cattle: Night soil Vegetable waste (quantities and potential gas yield) 1. 2. Totals biomass and potential gas production a) easy to procure: b) less easy to procure: Balancing 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 +

Plant Design and Construction

	Data	Rating
Selection of plant design Locally customary type of plant: Arguments in favor of floating-drum plant: Arguments in favor of fixe-dome plant: Arguments in favor of other plant(s): Type of plant chosen: Selection of site Availability of building materials Bricks/blocks/stone: Cement: Metal: Sand: Piping/fittings: Miscellaneous: Availability of gas appliances Cookers: Lamps: ... ...
Overall rating 3		- o +

Plant Operation / Maintenance / Repair

	Data	Rating
Assessment of plant operation Incidental work: Work expenditure in h: Persons responsible: Rating with regard to anticipated implementation:		- o +
Plant maintenance Maintenance-intensive components: Maintenance work by user: Maintenance work by external assistance: Rating with regard too anticipated implementation:		- o +
Plant repair 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 +

Economic Analysis

	Data	Rating
Time-expenditure accounting Time saved with biogas plant Time lost due to biogas plant Rating:		- o +
Microeconomic analysis Initial investment: Cost of operation/maintenance/repair: Return on investment: energy, fertilizer, otherwise: Payback time (static): Productiveness (static): Rating:		- o +
Quality factors, useful socioeconomic effects and costs 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 +

Social Acceptance and Potential for Dissemination

	Data	Rating
Anticipated acceptance Participation in planning and construction Integration into agricultural setting: Integration into household: Sociocultural acceptance: Rating:		- o +
Establishing a dissemination strategy Conditions for and chances of the professional-craftsman approach: Conditions for and chances of the self-help oriented approach:		- o + - o +
General conditions for dissemination Project-executing organization and its staffing: orgnaizational structure: interest and prior experience in biogas technology: Regional infrastructure for transportation: communication: material procurement: Craftsman involvement, i.e. which acitivities: minimum qualifications: tools and machines: Training for engineers, craftsman and users: Proprietary capital, subsidy/credit requirement on the part of user: craftsmen: Rating:		- o +
Overall rating 6		- o +

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 +

Further Information

• "Biogas Portal"