|
|
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| <br/> | | <br/> |
| | | |
− | | + | = Considering Biogas = |
− | = Considering a Biogas Plant = | + | |
| | | |
| Throughout the world, a countless number of designs of biogas plants have been developed under specific climatic and socio-economic conditions. Chosing a design is essentially part of the planning process. It is, however, important to familiarize with basic design considerations before the actual planning process begins. This refers to the planning of a single biogas unit as well as to the planning of biogas-programs with a regional scope. | | Throughout the world, a countless number of designs of biogas plants have been developed under specific climatic and socio-economic conditions. Chosing a design is essentially part of the planning process. It is, however, important to familiarize with basic design considerations before the actual planning process begins. This refers to the planning of a single biogas unit as well as to the planning of biogas-programs with a regional scope. |
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| The performance of a biogas plant is dependent on the local conditions in terms of climate, soil conditions, the substrate for digestion and building material availability. The design must respond to these conditions. In areas with generally low temperatures, insulation and heating devices may be important. If bedrock occurs frequently, the design must avoid deep excavation work. The amount and type of substrate to be digested have a bearing on size and design of the digester and the inlet and outlet construction. The choice of design will also be based on the building materials which are available reliably and at reasonable cost. | | The performance of a biogas plant is dependent on the local conditions in terms of climate, soil conditions, the substrate for digestion and building material availability. The design must respond to these conditions. In areas with generally low temperatures, insulation and heating devices may be important. If bedrock occurs frequently, the design must avoid deep excavation work. The amount and type of substrate to be digested have a bearing on size and design of the digester and the inlet and outlet construction. The choice of design will also be based on the building materials which are available reliably and at reasonable cost. |
| | | |
− | Excluding Factors | + | <br/> |
| + | |
| + | <u>Excluding Factors</u> |
| | | |
| If only one of the following criteria is evident, then the widespread dissemination of simple household biogas plants is not possible. As an exception, suitable farms in the region could allow individual measures that make biogas a feasible technology. | | If only one of the following criteria is evident, then the widespread dissemination of simple household biogas plants is not possible. As an exception, suitable farms in the region could allow individual measures that make biogas a feasible technology. |
Line 45: |
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| *no suitable institution can be found for dissemination | | *no suitable institution can be found for dissemination |
| | | |
| + | <br/> |
| | | |
− | = Critical Factors =
| + | <u>Critical Factors</u> |
| | | |
| Each of the following factors will lead to severe problems in biogas dissemination. Accompanying measures, particularly modified technical developments, high financial promotion or additional organizational structures within the dissemination program are necessary to guarantee project success. | | Each of the following factors will lead to severe problems in biogas dissemination. Accompanying measures, particularly modified technical developments, high financial promotion or additional organizational structures within the dissemination program are necessary to guarantee project success. |
Line 60: |
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| *no substantial interest of the government is evident | | *no substantial interest of the government is evident |
| | | |
− | = Ideal Conditions =
| + | <br/> |
| + | |
| + | <u>Ideal Conditions</u> |
| | | |
| If each of the following conditions is fulfilled then household biogas plants will definitely be a success. A dissemination program is then strongly recommended. | | If each of the following conditions is fulfilled then household biogas plants will definitely be a success. A dissemination program is then strongly recommended. |
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| *gas utilization and attendance of the plant can be clearly regulated within the household | | *gas utilization and attendance of the plant can be clearly regulated within the household |
| *moderate price of plant in relation to the income of the target group | | *moderate price of plant in relation to the income of the target group |
− | *economically healthy farms open to 'modernization'
| |
| *insufficient and expensive supply of fossil sources of energy | | *insufficient and expensive supply of fossil sources of energy |
| *building materials and gas appliances available locally | | *building materials and gas appliances available locally |
− | *qualified artisans exist locally
| |
| *counterpart organization has access to and experience in contact with the target group | | *counterpart organization has access to and experience in contact with the target group |
| *efficient counterpart organizations with the experience in cooperating with the private sector | | *efficient counterpart organizations with the experience in cooperating with the private sector |
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| *secured financing of the dissemination structure | | *secured financing of the dissemination structure |
| | | |
− | == Skills and Labor ==
| + | <br/> |
− | | + | |
− | High sophistication levels of biogas technology require high levels of skills, from the planner as well as from the constructor and user. With a high [[Educational and Training Programs for Biogas Projects|training input]], skill gaps can be bridged, but the number of skilled technicians will get smaller the more intensive the training has to be. In addition, training costs compete with actual construction costs for scarce (project) resources. Higher technical sophistication also requires more expensive supervision and, possibly, higher maintenance costs. To which extent prefabricated designs are suitable depends largely on the cost of labor and transport.
| + | |
− | | + | |
| | | |
| == Standardization == | | == Standardization == |
Line 113: |
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| <br/> | | <br/> |
| | | |
| + | <br/> |
| | | |
− | = The Planning Guide = | + | = Planning Guide for Domestic Biogas = |
| | | |
| 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. | | 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. |
| | | |
− | <u>Evaluation criteria are:</u> | + | <u>Evaluation criteria are:</u><br/> |
− | * | + | *<span style="font-weight: bold; line-height: 1.5em; font-size: 0.85em;">Siting condition are favorable</span> |
− | **
| + | ****;'''o''' Siting condition are unfavorable, but |
− | ***
| + | |
− | ****
| + | |
− | *****
| + | |
− | ******
| + | |
− | *******
| + | |
− | ****************;'''+''' Siting condition are favorable
| + | |
− | *;'''o''' Siting condition are unfavorable, but | + | |
| *:a) compensable by project activities | | *:a) compensable by project activities |
| *:b) not serious enough to cause ultimate failure | | *:b) not serious enough to cause ultimate failure |
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| 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.<br/> | | 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.<br/> |
| | | |
− | = Initial Situation = | + | == Initial Situation == |
| | | |
| {| cellpadding="10" border="1" style="width: 100%" | | {| cellpadding="10" border="1" style="width: 100%" |
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| <br/> | | <br/> |
| | | |
− | = Natural / Agricultural Conditions = | + | == Natural / Agricultural Conditions == |
| | | |
| {| cellpadding="10" border="1" style="width: 100%" | | {| cellpadding="10" border="1" style="width: 100%" |
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| <br/> | | <br/> |
| | | |
− | = Balancing the Energy Demand with the Biogas Production = | + | == Balancing the Energy Demand with the Biogas Production == |
| | | |
| {| cellpadding="10" border="1" style="width: 100%" | | {| cellpadding="10" border="1" style="width: 100%" |
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| |- | | |- |
| | '''Prior energy supply''' | | | '''Prior energy supply''' |
− | Uses, source of energy, consumption: | + | Uses, source of energy, consumption:<br/> |
− | * | + | *'''Anticipated biogas demand (kwh/day or l/d)''' |
− | **
| + | ****:for cooking:<br/> |
− | ***
| + | |
− | ****
| + | |
− | *****
| + | |
− | ******
| + | |
− | *******
| + | |
− | ****************;'''Anticipated biogas demand (kwh/day or l/d)'''<br/>
| + | |
− | *:for cooking:<br/> | + | |
| *:for lighting:<br/> | | *:for lighting:<br/> |
| *:for cooling:<br/> | | *:for cooling:<br/> |
Line 261: |
Line 247: |
| *:b) desired demand coverage: | | *:b) desired demand coverage: |
| | | |
− | '''Available biomass (kg/d) and potential gas production (l/d)''' | + | '''Available biomass (kg/d) and potential gas production (l/d) '''<span style="font-weight: bold; line-height: 1.5em;">from animal husbandry</span> |
| * | | * |
− | ** | + | ****:pigs: |
− | *** | + | |
− | ****
| + | |
− | *****
| + | |
− | ******
| + | |
− | *******
| + | |
− | ****************;from animal husbandry
| + | |
− | *:pigs: | + | |
| *:poultry: | | *:poultry: |
| *:cattle: | | *:cattle: |
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| <br/> | | <br/> |
| | | |
− | = Plant Design and Construction = | + | == Plant Design and Construction == |
| | | |
| {| cellpadding="10" border="1" style="width: 100%" | | {| cellpadding="10" border="1" style="width: 100%" |
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| <br/> | | <br/> |
| | | |
− | = Plant Operation / Maintenance / Repair = | + | == Plant Operation / Maintenance / Repair == |
| | | |
| {| cellpadding="10" border="1" style="width: 100%" | | {| cellpadding="10" border="1" style="width: 100%" |
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| <br/> | | <br/> |
| | | |
− | = Economic Analysis = | + | == Economic Analysis == |
| | | |
| {| cellpadding="10" border="1" style="width: 100%" | | {| cellpadding="10" border="1" style="width: 100%" |
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| <br/> | | <br/> |
| | | |
− | = Social Acceptance and Potential for Dissemination = | + | == Social Acceptance and Potential Dissemination == |
| | | |
| {| cellpadding="10" border="1" style="width: 100%" | | {| cellpadding="10" border="1" style="width: 100%" |
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| <br/> | | <br/> |
| | | |
| + | = Planning Guide for Industrial Biogas = |
| + | |
| + | == Steps of planning == |
| + | |
| + | The following steps serve as a step by step guideline to reach a decision whether a biogas project is technically and economically feasible. |
| + | |
| + | '''Basic steps in planning a biogas plant according to '''[http://giz.energypedia.info/Enterprises Krieg & Fischer]''':''' |
| + | #Calculation of biogas amount |
| + | #Size of digester |
| + | #Size of engine |
| + | #Sitelayout |
| + | #Flow chart |
| + | #Estimate of costs |
| | | |
| <br/> | | <br/> |
| | | |
| + | '''Basic Steps according to the "Guide to Biogas" from FNR:''' |
| + | |
| + | === Step 1: Preparing the project outline === |
| + | |
| + | {| cellspacing="1" cellpadding="1" align="center" border="1" style="font-size: 14px; width: 777px;" |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | Long-term availability of substrates |
| + | | Which substrates will be available on a long-term basis?<br/>What impact/changes in the medium- and long-term are possible at the specific site?<br/>How will this affect the planned biogas plant? (biology/materials, process, energy)<br/>Is the supply of substrates guaranteed on the long term?<br/>Is the use of these substrates worthwhile in view of the statutory requirements? (question of proportionality) |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | Concepts of exemplary biogas plants |
| + | | Go and visit some existing plants as a way of acquiring experience and information.<br/>What structural options are available on the market?<br/>Where are there structural/process-related problems? How were those problems solved?<br/>What has been the experience of existing plant operators with various components and substrate combinations? |
| + | |} |
| + | |
| + | <br/> |
| + | |
| + | '''Goals''' |
| + | *'''Initial assessment of the possibilities''' |
| + | *'''Gathering of experience from other [http://giz.energypedia.info/GIZ programms related to Biogas biogas plants]''' |
| + | *'''Acquisition of knowledge about what [http://giz.energypedia.info/Construction of a biogas plant plants/components are] available on the market'''<br/> |
| + | |
| + | <br/>[http://giz.energypedia.info/index.php/Portal:GIZ_Bio_Energy ►Return to Main Page]<br/> |
| + | |
| + | === Step 2: Developing the feasibility study === |
| + | |
| + | {| cellspacing="1" cellpadding="1" align="center" border="1" style="font-size: 14px; width: 777px;" |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | Availability of [https://energypedia.info/index.php/Substrate_Types_and_Management substrates] |
| + | | |
| + | Check whether it makes sense to have a feasibility study carried out by using the |
| + | |
| + | [http://giz.energypedia.info/Pre-feasibility study template pre-feasibility study template] |
| + | |
| + | Engage the services of an experienced and reputable engineering firm/engineering department of an experienced<br/>and reputable plant manufacturer. |
| + | |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | Get in touch with an [http://giz.energypedia.info/Who is who in Biogas agricultural adviser] / professional consultancy |
| + | | An agricultural adviser or biogas consultant experienced in the building and operation of biogas plants should be approached for site selection and plant design through, construction and commissioning. |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | Decision on the type of plant and construction procedure as well as on the size of plant. |
| + | | |
| + | Definition of the site characteristics, e.g. ordering of a soil report. Site selection (with reference to a general plan of the farm, buildings, silo areas). |
| + | |
| + | Location of the nearest power or gas feed-in point.<br/>Decision on appropriate plant configuration/design and technology with reference to future vision for the site of application and operational restructuring measures necessitated by the biogas plant. |
| + | |
| + | Sizing of the plant components according to an analysis of potentials. |
| + | |
| + | <br/>'''Question of procedure:''' |
| + | |
| + | How should the project be implemented? Is a turn-key plant possible?<br/>What does the plant [http://giz.energypedia.info/Construction of a biogas plant construction process] look like?<br/>How high is the available workforce? |
| + | |
| + | Can the project be multiplicated to other sites?<br/>Which contract works are planned to put out to tender? (e.g. earthworks, electrics…) |
| + | |
| + | |} |
| + | |
| + | <br/> |
| + | |
| + | '''Goals''' |
| + | *'''Involvement of an experienced engineering firm or adviser for preparation of a feasibility study.''' |
| + | *'''Determination of the preferred size of plant and type of plant/procedure with possible feedin points for power, heat or processed biogas''' |
| + | |
| + | Engineering firms and companies that we have experience with take a look at the [http://giz.energypedia.info/Service Pack Biogas Who is Who in Biogas.] |
| + | |
| + | [http://giz.energypedia.info/index.php/Portal:GIZ_Bio_Energy ►Return to Main Page]<br/> |
| + | |
| + | === Step 3: Availability of substrate === |
| + | |
| + | {| cellspacing="1" cellpadding="1" align="center" border="1" style="font-size: 14px; width: 777px;" |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 200px;" | Available substrates |
| + | <br/> |
| + | |
| + | | style="width: 537px;" | Which biomass substrates are available: |
| + | *agricultural residues (e.g. [https://energypedia.info/index.php/Substrate_Types_and_Management#Cattle_dung_and_manure cattle manure], poultry excrement) |
| + | *agroindustrial wastes (e.g. apple mash, POME) |
| + | *wastes from trade and industry (e.g. grease trap waste) |
| + | *wastes from private households (e.g. biowastes) |
| + | *renewable resources, energy crops (e.g.maize silage, grass silage) |
| + | |
| + | At what times will the substrates be available? |
| + | |
| + | In what quality will the substrates be supplied? |
| + | |
| + | |- bgcolor="#ccffcc" |
| + | | Biomass suppliers |
| + | | bgcolor="#ffffff" | Who are the potential long-term suppliers of substrates? |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 229px;" | Costs of supply |
| + | | How much will the substrates cost to supply (price of substrate, transport, workforce)? |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 229px;" | Storage area |
| + | | How much storage area will be needed at the planned site of the plant? |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 229px;" | Pretreatment |
| + | | How much pretreatment (e.g. mixing, comminution) will the envisaged substrates require? |
| + | |} |
| + | |
| + | <br/> |
| + | |
| + | '''Goals''' |
| + | *'''Selection of substrates with a view to a workable digestion process.''' |
| + | *'''Definition of measures for pretreatment and processing of substrates.''' '''Selection of potential biomass suppliers.''' |
| + | |
| + | <br/> |
| + | |
| + | <br/>[http://giz.energypedia.info/index.php/Portal:GIZ_Bio_Energy ►Return to Main Page]<br/> |
| + | |
| + | === Step 4: Selecting the site === |
| + | |
| + | [[File:Criteria for site selection.JPG|frame|right|180px|Criteria for site selection.JPG]] |
| + | |
| + | It must first of all be clarified whether the preferred site is of the necessary size, whether the subsoil is suitable and, if possible, free from contamination, whether any existing buildings and storage areas are in a usable condition and whether grid connection points and heat offtakers are available. The purpose of such an assessment is to keep down the construction costs. The relatively low capacitiesinvolved in agricultural biogas production and the associated substrate streams allow the supply of substrate and the disposal of digestate to be effected by road transport. Many substrates scarcely merit the cost of transport on account of their relatively low energy density. Consequently, the search for substrates with which to supply the biogas plant will focus on biomass that is available from the immediate regional vicinity. It will be advantageous to select a site that has access to roads of average transport capacity (such as country roads/B-roads.) |
| + | |
| + | {| cellspacing="1" cellpadding="1" align="center" border="1" style="font-size: 14px; width: 777px;" |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | The site |
| + | | What is the site like?<br/>Is the subsoil suitable? |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | The infrastructure |
| + | | |
| + | Is the site in an industrial zone (on the periphery) or on a farm in the outer zone?<br/>How high are the land costs?<br/>Is the road access suitable for trucks? |
| + | |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | Options for heat utilisation |
| + | | |
| + | Can the waste heat from the CHP process be used at the site or nearby? |
| + | |
| + | Are the associated conversion works/costs in proportion to the benefit? How much heat needs to be supplied every month?<br/>Does the possibility exist to set up a satellite CHP unit (CHP unit physically separate from the biogas plant and connected to the gas tank by a relatively long gas pipeline)? |
| + | |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | Options for power feed-in |
| + | | Which utilities (power, water, sewage, telecoms, natural gas) are available at the site? How far away is the nearest power feed-in point? |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | Local acceptance |
| + | | Which local residents and businesses will be affected?<br/>Which local residents and businesses need to be informed about the project at an early stage and, where appropriate, involved in the project?<br/>Are there potential heat offtakers?<br/>Which public institutions need to be included at an early stage?<br/>What nature conservation interests need to be addressed? |
| + | |} |
| + | |
| + | <br/> |
| + | |
| + | '''Goals''' |
| + | *'''Selection of the site''' |
| + | *'''Selection of form of biogas utilisation (CHP unit at the site, setting-up of a satellite CHP unit or processing of biogas for feed-in to the natural gas grid)''' |
| + | *'''Building-up of local acceptance through campaign and Human Capacity Development''' |
| + | |
| + | <br/>Find another detailed site evaluation procedure in [https://energypedia.info/index.php/Siting_of_the_Biogas_Unit energypedia.] |
| + | |
| + | <br/>[http://giz.energypedia.info/index.php/Portal:GIZ_Bio_Energy ►Return to Main Page]<br/> |
| + | |
| + | === Step 5: Material stream logistics === |
| + | |
| + | {| cellspacing="1" cellpadding="1" align="center" border="1" style="font-size: 14px; width: 777px;" |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | Material stream volumes |
| + | | |
| + | What volumes of substrates are included?<br/>How wide is the average radius of potential substrate suppliers?<br/>How is the seasonal arising of substrates? |
| + | |
| + | What are the properties of the envisaged substrates? |
| + | |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | Substrate supply chain |
| + | | |
| + | What form of substrate delivery is most efficient?<br/>What types of long- and short-term storage are available at the site?<br/>What forms of treatment and metering are required? |
| + | |
| + | What degree of price uncertainty exists in relation to the purchase of substrates? |
| + | |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | Biomass suppliers and digestate offtakers |
| + | | What substrate delivery terms and quality standards exist? (e.g. billing of the delivered biomass quantity/volume)<br/>Are there offtakers for the digestate? |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | Substrate transport inside the plant |
| + | | What handling/transport equipment is needed?<br/>What conveying/pumping equipment will I need inside the plant? |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | Storage of digestate |
| + | | What quantities of digestate will be produced?<br/>What method of digestate storage is structurally possible?<br/>What method of digestate transport and what digestate field spreading intervals are possible? |
| + | |} |
| + | |
| + | '''Goals''' |
| + | *'''Determination of transport and handling technologies''' |
| + | *'''Definition of available area for substrate and digestate storage at the site of the biogas plant''' |
| + | *'''Selection of biomass suppliers and digestate offtakers''' |
| + | *'''Definition of supply agreements and, if possible, long-term supply contracts''' |
| + | |
| + | [http://giz.energypedia.info/index.php/Portal:GIZ_Bio_Energy ►Return to Main Page] |
| + | |
| + | <br/> |
| + | |
| + | === Step 6: Selecting the technology === |
| + | |
| + | {| cellspacing="1" cellpadding="1" align="center" border="1" style="font-size: 14px; width: 777px;" |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | Selection of digestion process |
| + | | Will the plant use wet or dry digestion?<br/>What process stages will the plant use? And at what process temperature? |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | Select the plant components |
| + | | What components will the plant use? |
| + | *Receiving, treatment and loading equipment |
| + | *Digester with internal components and agitator system |
| + | *Type of gas tank |
| + | *Method of digestate storage |
| + | *Biogas utilisation |
| + | |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | Involved parties |
| + | | Which farms and enterprises will be involved as network partners?<br/>experience do the involved parties have?<br/>What installation and maintenance firms are available in the immediate vicinity?<br/>How much do my staff and partners know about substrate treatment/loading or about transport/silage equipment? |
| + | |} |
| + | |
| + | '''Goals''' |
| + | *'''Selection of state-of-the-art plant components of high-grade, maintenance-friendly materials with automated operation.''' |
| + | |
| + | [http://giz.energypedia.info/index.php/Portal:GIZ_Bio_Energy ►Return to Main Page]<br/> |
| + | |
| + | === Step 7: Recovering the energy from the biogas === |
| + | |
| + | {| cellspacing="1" cellpadding="1" align="center" border="1" style="font-size: 14px; width: 777px;" |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | Type of biogas utilisation |
| + | | How can the produced biogas be efficiently used at the site?<br/> |
| + | *Combined heat and power (CHP) generation (e.g. CHP unit, micro gas turbine, etc.) |
| + | *Cold generation by trigeneration process |
| + | *Upgrading of biogas (dehumidification and desulphurisation) to natural gas quality for feed-in to the public natural gas grid or micro gas grids |
| + | *Processing into fuel for motor vehicles |
| + | *Recovery of heat from biogas |
| + | |
| + | |} |
| + | |
| + | '''Goals''' |
| + | *'''Selection of method of energy recovery from biogas''' |
| + | |
| + | <br/>[http://giz.energypedia.info/index.php/Portal:GIZ_Bio_Energy ►Return to Main Page]<br/> |
| + | |
| + | <br/> |
| + | |
| + | === Step 8: Evaluation and decision-making === |
| + | |
| + | {| cellspacing="1" cellpadding="1" align="center" border="1" style="font-size: 14px; width: 777px;" |
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| + | | bgcolor="#ccffcc" style="width: 228px;" | Detailed cost budget |
| + | | |
| + | A detailed cost budget can be drawn up based on the selected procedure. The cost budget should allow budgetary control at all times. |
| + | |
| + | The cost items should be broken down into the following blocks: |
| + | *costs of individual components |
| + | *substrate costs (delivery 'free to digester') |
| + | *depreciation |
| + | *maintenance and repair |
| + | *interest |
| + | *insurance |
| + | *labour costs |
| + | *financing/permitting costs |
| + | *planning/engineering costs |
| + | *utility costs, grid connection costs |
| + | *transport costs |
| + | *overheads (telephone, rooms, utilities, etc.) |
| + | |
| + | |- |
| + | | bgcolor="#ccffcc" style="width: 228px;" | Possibilities of subsidies and international fundings |
| + | | |
| + | Which possible mechanisms of funding can be used for the project? |
| + | |
| + | |} |
| + | |
| + | <br/>'''Goals''' |
| + | *'''Preparation of a profitability analysis, taking account of the assessment of other advantages''' |
| + | *'''Profitability analysis as a decision-making basis''' |
| + | |
| + | <br/>[http://giz.energypedia.info/index.php/Portal:GIZ_Bio_Energy ►Return to Main Page] |
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| = Further Information = | | = Further Information = |
Failure or unsatisfactory performance of biogas units occur mostly due to planning mistakes. The consequences of such mistakes may be immediately evident or may only become apparent after several years. Thorough and careful planning is, therefore, of utmost importance to eliminate mistakes before they reach irreversible stages.
As a biogas unit is an expensive investment, it should not be erected as a temporary set-up. Therefore, determining siting criteria for the stable and the biogas plant are the important initial steps of planning.
A general problem for the planning engineer is the interference of the customer during planning. As much as the wishes and expectations of customers have to be taken into consideration, the most important task of the planner is to lay the foundation for a well functioning biogas unit. As in most cases the customer has no experience with biogas technology, the planner has to explain all the reasons for each planning step. Planners should have the courage to withdraw from the planning process, if the wishes of the customer will lead to a white elephant on the farm.
Moreover, all extension-service advice concerning agricultural biogas plants must begin with an estimation of the quantitative and qualitative energy requirements of the interested party. Then, the biogas-generating potential must be calculated on the basis of the given biomass production and compared to the energy demand. Both the energy demand and the gas-generating potential, however, are variables that cannot be accurately determined in the planning phase. Sizing the plant(digester, gasholder, etc.) is the next step in the planning process.
In the case of a family-size biogas plant intended primarily as a source of energy, implementation should only be recommended, if the plant can be expected to cover the calculated energy demand.
Information about the economic evaluation of a biogas plant can be found in the section on Costs and Benefits.
Before building a biogas plant, there are different circumstances which should be considered. For instance, the natural and agricultural conditions in the specific countries are as important as the social or the economic aspects. To consider the most important factors, we provide a checklist for the planning procedure, a planning guide and a checklist for construction of a biogas plant.
Throughout the world, a countless number of designs of biogas plants have been developed under specific climatic and socio-economic conditions. Chosing a design is essentially part of the planning process. It is, however, important to familiarize with basic design considerations before the actual planning process begins. This refers to the planning of a single biogas unit as well as to the planning of biogas-programs with a regional scope.
The performance of a biogas plant is dependent on the local conditions in terms of climate, soil conditions, the substrate for digestion and building material availability. The design must respond to these conditions. In areas with generally low temperatures, insulation and heating devices may be important. If bedrock occurs frequently, the design must avoid deep excavation work. The amount and type of substrate to be digested have a bearing on size and design of the digester and the inlet and outlet construction. The choice of design will also be based on the building materials which are available reliably and at reasonable cost.
If only one of the following criteria is evident, then the widespread dissemination of simple household biogas plants is not possible. As an exception, suitable farms in the region could allow individual measures that make biogas a feasible technology.
Each of the following factors will lead to severe problems in biogas dissemination. Accompanying measures, particularly modified technical developments, high financial promotion or additional organizational structures within the dissemination program are necessary to guarantee project success.
If each of the following conditions is fulfilled then household biogas plants will definitely be a success. A dissemination program is then strongly recommended.
For larger biogas programs, especially when aiming at a self-supporting dissemination process, standards in dimensions, quality and pricing are essential. Standard procedures, standard drawings and forms and standardized contracts between the constructor, the planner, the provider of material and the customer avoid mistakes and misunderstandings and save time. There is, however a trade-off between the benefits of standardization and the necessity of individual, appropriate solutions.
The design selection is determined largely be the prevailing design in the region, which, in turn takes the climatic, economic and substrate specific conditions into consideration. Large plants are designed on a case-to-case basis.
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.
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.
The following steps serve as a step by step guideline to reach a decision whether a biogas project is technically and economically feasible.
It must first of all be clarified whether the preferred site is of the necessary size, whether the subsoil is suitable and, if possible, free from contamination, whether any existing buildings and storage areas are in a usable condition and whether grid connection points and heat offtakers are available. The purpose of such an assessment is to keep down the construction costs. The relatively low capacitiesinvolved in agricultural biogas production and the associated substrate streams allow the supply of substrate and the disposal of digestate to be effected by road transport. Many substrates scarcely merit the cost of transport on account of their relatively low energy density. Consequently, the search for substrates with which to supply the biogas plant will focus on biomass that is available from the immediate regional vicinity. It will be advantageous to select a site that has access to roads of average transport capacity (such as country roads/B-roads.)