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| − | [[File:GIZ HERA Cooking Energy Compendium small.png|left|831px|GIZ HERA Cooking Energy Compendium|alt=GIZ HERA Cooking Energy Compendium small.png|link=GIZ HERA Cooking Energy Compendium]]<br/>[[GIZ HERA Cooking Energy Compendium#Basics about Cooking Energy|Basics]] | [[GIZ HERA Cooking Energy Compendium#Policy Advice on Cooking Energy|Policy Advice]] | [[GIZ HERA Cooking Energy Compendium#Planning Improved Cook Stove .28ICS.29 Interventions|Planning]] | [[GIZ HERA Cooking Energy Compendium#Designing and Implementing Improved Cookstoves .28ICS.29 Supply Interventions|Designing and Implementing (ICS Supply)]]| [[GIZ HERA Cooking Energy Compendium#Cooking Energy Technologies and Practices|Technologies and Practices]] | '''[[GIZ HERA Cooking Energy Compendium#Designing and Implementing Woodfuel Supply Interventions|Designing and Implementing (Woodfuel Supply)]]'''| [[GIZ HERA Cooking Energy Compendium#Climate Change Related Issues|Climate Change]] | + | [[File:GIZ HERA Cooking Energy Compendium small.png|left|831px|GIZ HERA Cooking Energy Compendium|alt=GIZ HERA Cooking Energy Compendium small.png|link=GIZ HERA Cooking Energy Compendium]]<br/><br/><!-- |
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| + | -->{{#ifeq: {{#show: {{PAGENAME}} |?Hera category}} | Cooking Energy System |'''[[GIZ HERA Cooking Energy Compendium#Cooking Energy Technologies and Practices|Cooking Energy System]]''' {{!}} | [[GIZ HERA Cooking Energy Compendium#Cooking Energy Technologies and Practices|Cooking Energy System]] {{!}} | }} <!-- |
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| − | = Supply Assessment =
| + | -->{{#ifeq: {{#show: {{PAGENAME}} |?Hera category}} | Basics |'''[[GIZ HERA Cooking Energy Compendium#Basics about Cooking Energy|Basics]]''' {{!}} | [[GIZ HERA Cooking Energy Compendium#Basics about Cooking Energy|Basics]] {{!}} | }} <!-- |
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| | + | -->{{#ifeq: {{#show: {{PAGENAME}} |?Hera category}} | Policy Advice |'''[[GIZ HERA Cooking Energy Compendium#Policy Advice on Cooking Energy|Policy Advice]]''' {{!}} | [[GIZ HERA Cooking Energy Compendium#Policy Advice on Cooking Energy|Policy Advice]] {{!}} | }} <!-- |
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| | + | -->{{#ifeq: {{#show: {{PAGENAME}} |?Hera category}} | Planning |'''[[GIZ HERA Cooking Energy Compendium#Planning Cooking Energy Interventions|Planning]]''' {{!}} | [[GIZ HERA Cooking Energy Compendium#Planning Cooking Energy Interventions|Planning]] {{!}} | }} <!-- |
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| | + | -->{{#ifeq: {{#show: {{PAGENAME}} |?Hera category}} | ICS Supply |'''[[GIZ HERA Cooking Energy Compendium#Designing and Implementing Improved Cookstoves .28ICS.29 Supply Interventions|Designing and Implementing ICS Supply]]''' {{!}} | [[GIZ HERA Cooking Energy Compendium#Designing and Implementing Improved Cookstoves .28ICS.29 Supply Interventions|Designing and Implementing ICS Supply]] {{!}} | }} <!-- |
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| | + | -->{{#ifeq: {{#show: {{PAGENAME}} |?Hera category}} | Woodfuel Supply |'''[[GIZ HERA Cooking Energy Compendium#Designing and Implementing Woodfuel Supply Interventions|Designing and Implementing Woodfuel Supply]]''' {{!}} | [[GIZ HERA Cooking Energy Compendium#Designing and Implementing Woodfuel Supply Interventions|Designing and Implementing Woodfuel Supply]] {{!}} | }} <!-- |
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| | + | -->{{#ifeq: {{#show: {{PAGENAME}} |?Hera category}} | Climate Change |'''[[GIZ HERA Cooking Energy Compendium#Climate Change Related Issues|Climate Change]]''' | [[GIZ HERA Cooking Energy Compendium#Climate Change Related Issues|Climate Change]] {{!}} | }} <!-- |
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| | + | -->{{#ifeq: {{#show: {{PAGENAME}} |?Hera category}} | Extra |'''[[GIZ HERA Cooking Energy Compendium#Climate Change Related Issues|Extra]]''' | [[GIZ HERA Cooking Energy Compendium#Climate Change Related Issues|Extra]] }} |
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| | + | = Overview = |
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| | Sound information on baseline forest resources is a precondition for shaping woodfuel supply strategies on national and/or sub-national levels. Theoretically, there are two main sources for woodfuel information: forestry services and energy agencies. Their approaches differ significantly. Analyzing information from these sources is challenging as there are often discrepancies in the reported values: definitions are seldom consistent; measurement units are different; conversion factors needed are not always available etc. Deficiencies of data, coupled with the failure to prioritize forest energy at policy level, frequently result in the absence of legislation on sectoral wood energy. | | Sound information on baseline forest resources is a precondition for shaping woodfuel supply strategies on national and/or sub-national levels. Theoretically, there are two main sources for woodfuel information: forestry services and energy agencies. Their approaches differ significantly. Analyzing information from these sources is challenging as there are often discrepancies in the reported values: definitions are seldom consistent; measurement units are different; conversion factors needed are not always available etc. Deficiencies of data, coupled with the failure to prioritize forest energy at policy level, frequently result in the absence of legislation on sectoral wood energy. |
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| | + | = Supply Assessment = |
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| | The process of collecting and verifying facts and figures is a laborious, costly and time-consuming undertaking, requiring properly trained and qualified personnel. | | The process of collecting and verifying facts and figures is a laborious, costly and time-consuming undertaking, requiring properly trained and qualified personnel. |
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| | - > [http://www.fao.org/docrep/010/i0152e/i0152e00.HTM WISDOM for Cities. Analysis of wood energy and urbanization using WISDOM methodology]<br/> | | - > [http://www.fao.org/docrep/010/i0152e/i0152e00.HTM WISDOM for Cities. Analysis of wood energy and urbanization using WISDOM methodology]<br/> |
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| | | style="vertical-align: top; width: 100%" | | | | style="vertical-align: top; width: 100%" | |
| | <u>A '''WISDOM analysis''' involves five main steps:</u> | | <u>A '''WISDOM analysis''' involves five main steps:</u> |
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| | #selection of the spatial base | | #selection of the spatial base |
| | #development of the demand module | | #development of the demand module |
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| | As a consequence, forest resource assessments have to be complemented by legal, regulatory, institutional, and socio-economic studies that analyse the framework conditions. | | As a consequence, forest resource assessments have to be complemented by legal, regulatory, institutional, and socio-economic studies that analyse the framework conditions. |
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| | Table 5 provides a summary of these factors as well as how to use them to estimate wood supplies. | | Table 5 provides a summary of these factors as well as how to use them to estimate wood supplies. |
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| − | | '''Table 5: Estimating actual and potential wood supplies''' | + | | '''Table 5: Estimating actual and potential wood supplies<ref name="Steve Sepp, eco-consult">Steve Sepp, eco-consult</ref>''' |
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| | | colspan="2" | '''Supply factors''' | | | colspan="2" | '''Supply factors''' |
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| − | <font size="2"><span id="1227183625767S" style="display: none"></span></font> | + | <font size="2"><span style="display: none" id="1227183625767S"></span></font> |
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| − | Source: Steve Sepp, eco-consult<br/>
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| | Wood is the most widely used resource that provides thermal energy in the world, so high conversion efficiency into energy is a key issue. Utmost care should be taken when using conversion factors, as this is a major cause of serious miscalculation. Foresters in general distinguish between ‘standing stock’ measured in solid cubic meters, and ‘harvested woodfuel’ measured in stacked cubic meters (containing air spaces between the pieces of wood), which are often called stere. A well-piled stacked cubic meter may contain 0.65 m<sup>3</sup> solid (e.g. products from plantations) whereas a poorly stacked one may only have 0.33 m<sup>3</sup> solid (e.g twisted branches of sahelian shrubs); just half as much as the well-stacked wood. | | Wood is the most widely used resource that provides thermal energy in the world, so high conversion efficiency into energy is a key issue. Utmost care should be taken when using conversion factors, as this is a major cause of serious miscalculation. Foresters in general distinguish between ‘standing stock’ measured in solid cubic meters, and ‘harvested woodfuel’ measured in stacked cubic meters (containing air spaces between the pieces of wood), which are often called stere. A well-piled stacked cubic meter may contain 0.65 m<sup>3</sup> solid (e.g. products from plantations) whereas a poorly stacked one may only have 0.33 m<sup>3</sup> solid (e.g twisted branches of sahelian shrubs); just half as much as the well-stacked wood. |
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| − | Energy content is proportional to the dry-weight of wood; so higher density woods have higher calorific values. The reported range in wood densities is between 100 kg/m<sup>3 </sup> and 1200 kg/m<sup>3</sup>. Species used as woodfuel are generally from 650 kg/m<sup>3 </sup>to 750 kg/m<sup>3</sup>. The moisture content plays a crucial role in determining the calorific value (Table 3). The moisture content of wood is around 50 % (of total weight) when first harvested, whereas air-dried wood contains between 12% to 20% of moisture yielding a calorific value between 14 MJ/kg and 16 MJ/kg. To evaporate one kilogram of water takes about 2.5 MJ. In the case of charcoal, the calorific value is around 30 MJ/kg. In its statistics, the FAO uses a conversion factor of 165 kg of produced charcoal from one cubic meter of fuelwood (see also chapter on charcoal). | + | Energy content is proportional to the dry-weight of wood; so higher density woods have higher calorific values. The reported range in wood densities is between 100 kg/m<sup>3 </sup> and 1200 kg/m<sup>3</sup>. Species used as woodfuel are generally from 650 kg/m<sup>3 </sup>to 750 kg/m<sup>3</sup>. The moisture content plays a crucial role in determining the calorific value (Table 3). The moisture content of wood is around 50 % (of total weight) when first harvested, whereas air-dried wood contains between 12% to 20% of moisture yielding a calorific value between 14 MJ/kg and 16 MJ/kg. To evaporate one kilogram of water takes about 2.5 MJ. In the case of charcoal, the calorific value is around 30 MJ/kg. In its statistics, the FAO uses a conversion factor of 165 kg of produced charcoal from one cubic meter of fuelwood (see also chapter on charcoal). |
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| − | {| cellspacing="0" cellpadding="0" border="0" style="width: 100%" class="FCK__ShowTableBorders" | + | {| class="FCK__ShowTableBorders" style="width: 100%" cellspacing="0" cellpadding="0" border="0" |
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| − | | style="vertical-align: top; width: 300px" colspan="3" | | + | | colspan="3" style="vertical-align: top; width: 300px" | |
| | '''Table 2: Density (specific mass) and (net) calorific value (Heat of combustion) of some fuels''' | | '''Table 2: Density (specific mass) and (net) calorific value (Heat of combustion) of some fuels''' |
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| | '''<span>NB.: Values are approximate, since fuels vary in composition which affects both the density and calorific value.</span>''' | | '''<span>NB.: Values are approximate, since fuels vary in composition which affects both the density and calorific value.</span>''' |
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| | '''Table 3: Influence of wood moisture on calorific value''' | | '''Table 3: Influence of wood moisture on calorific value''' |
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| − | '''Moisture content %''' | + | '''Moisture content %''' |
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| | ''Assuming a mean value for 1 stere of wood = 0.5m<sup>3 </sup>and average density of 700kg/m<sup>3</sup><'' | | ''Assuming a mean value for 1 stere of wood = 0.5m<sup>3 </sup>and average density of 700kg/m<sup>3</sup><'' |
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| − | Weight of 1 stere of wood : 700 kg/m<sup>3 </sup>x 0.5 (stere/volume conversion)= 350 kg | + | Weight of 1 stere of wood : 700 kg/m<sup>3 </sup>x 0.5 (stere/volume conversion)= 350 kg |
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| | Energy content of 1 stere:<span>350 kg x 13 MJ/kg = 4,550 MJ</span> | | Energy content of 1 stere:<span>350 kg x 13 MJ/kg = 4,550 MJ</span> |
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| | <span><font size="2">Equivalent weight of LPG for 1 stere of wood =</font></span> | | <span><font size="2">Equivalent weight of LPG for 1 stere of wood =</font></span> |
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| | *<span><font size="2">4,550 MJ ÷45MJ = '''101 Kg LPG''' or in terms of litres of LPG:</font></span> | | *<span><font size="2">4,550 MJ ÷45MJ = '''101 Kg LPG''' or in terms of litres of LPG:</font></span> |
| | *<span><font size="2">101 ÷ 0.056 = '''200 litres of LPG'''</font></span> | | *<span><font size="2">101 ÷ 0.056 = '''200 litres of LPG'''</font></span> |
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| | <span>When estimating actual or potential wood supplies, an important distinction has to be made between:</span> | | <span>When estimating actual or potential wood supplies, an important distinction has to be made between:</span> |
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| | #<span>clear felling (often limited to plantations) and</span> | | #<span>clear felling (often limited to plantations) and</span> |
| | #<span>sustainable harvesting.</span> | | #<span>sustainable harvesting.</span> |
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| | <br/> | | <br/> |
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| − | <br/> | + | = Further Information<br/> = |
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| + | *[[Portal:Improved Cooking|Improved Cooking Portal on energypedia]] |
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| | = <span>References</span><br/> = | | = <span>References</span><br/> = |
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| − | <span><references /></span> | + | <span></span> |
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| − | <br/> | + | <span>This article was originally published by [http://www.giz.de/fachexpertise/html/2769.html GIZ HERA]. It is basically based on experiences, lessons learned and information gathered by GIZ cook stove projects. You can find more information about the authors and experts of the original “Cooking Energy Compendium” in the [[Imprint - GIZ HERA Cooking Energy Compendium|GIZ HERA Cooking Energy Compendium Imprint]].</span> |
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| − | <span>This article was originally published by [http://www.giz.de/fachexpertise/html/2769.html GIZ HERA]. It is basically based on experiences, lessons learned and information gathered by GIZ cook stove projects. You can find more information about the authors and experts of the original “Cooking Energy Compendium” in the [https://energypedia.info/wiki/Imprint_-_GIZ_HERA_Cooking_Energy_Compendium#Published_by GIZ HERA Cooking Energy Compendium Imprint].</span> | + | <span><references /></span> |
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| | + | <span></span> |
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| − | <span>[[Assessing Wood Fuel Supply Potentials#Supply Assessment|Top of the page]]</span>
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| | <span>[[GIZ HERA Cooking Energy Compendium|--> Back to Overview GIZ HERA Cooking Energy Compendium]]</span> | | <span>[[GIZ HERA Cooking Energy Compendium|--> Back to Overview GIZ HERA Cooking Energy Compendium]]</span> |
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| | + | {{#set: Hera category=Woodfuel Supply}} |
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| | [[Category:Wood_Energy]] | | [[Category:Wood_Energy]] |
| | [[Category:Cooking_Energy_Compendium_(GIZ_HERA)]] | | [[Category:Cooking_Energy_Compendium_(GIZ_HERA)]] |
Sound information on baseline forest resources is a precondition for shaping woodfuel supply strategies on national and/or sub-national levels. Theoretically, there are two main sources for woodfuel information: forestry services and energy agencies. Their approaches differ significantly. Analyzing information from these sources is challenging as there are often discrepancies in the reported values: definitions are seldom consistent; measurement units are different; conversion factors needed are not always available etc. Deficiencies of data, coupled with the failure to prioritize forest energy at policy level, frequently result in the absence of legislation on sectoral wood energy.
The process of collecting and verifying facts and figures is a laborious, costly and time-consuming undertaking, requiring properly trained and qualified personnel.
To alleviate these constraints, FAO published a guide outlining simple and rapid methods to verify existing data, to fill gaps in the information chain, and to conduct more reliable surveys
The methodology has been expanded to investigate the scope of urban woodfuel supply, which identifies the extent to which supply zones encroach into rural areas and forests. (The term “urban woodsheds” is analogous with the familiar geographic concept of watersheds.)
Woodfuel problems are not always simply a gap between demand and supply. They are increasingly regarded as a reflection of more systemic, and often locally site-specific deficiencies in land tenure, urban energy markets, and fiscal and incentive policies and in misallocation of forests and cropland.
As a consequence, forest resource assessments have to be complemented by legal, regulatory, institutional, and socio-economic studies that analyse the framework conditions.
Table 5 provides a summary of these factors as well as how to use them to estimate wood supplies.
Wood is the most widely used resource that provides thermal energy in the world, so high conversion efficiency into energy is a key issue. Utmost care should be taken when using conversion factors, as this is a major cause of serious miscalculation. Foresters in general distinguish between ‘standing stock’ measured in solid cubic meters, and ‘harvested woodfuel’ measured in stacked cubic meters (containing air spaces between the pieces of wood), which are often called stere. A well-piled stacked cubic meter may contain 0.65 m3 solid (e.g. products from plantations) whereas a poorly stacked one may only have 0.33 m3 solid (e.g twisted branches of sahelian shrubs); just half as much as the well-stacked wood.
Energy content is proportional to the dry-weight of wood; so higher density woods have higher calorific values. The reported range in wood densities is between 100 kg/m3 and 1200 kg/m3. Species used as woodfuel are generally from 650 kg/m3 to 750 kg/m3. The moisture content plays a crucial role in determining the calorific value (Table 3). The moisture content of wood is around 50 % (of total weight) when first harvested, whereas air-dried wood contains between 12% to 20% of moisture yielding a calorific value between 14 MJ/kg and 16 MJ/kg. To evaporate one kilogram of water takes about 2.5 MJ. In the case of charcoal, the calorific value is around 30 MJ/kg. In its statistics, the FAO uses a conversion factor of 165 kg of produced charcoal from one cubic meter of fuelwood (see also chapter on charcoal).
Table 2 shows characteristics of woodfuel compared to other fuels. Table 3 depicts the influence that wood moisture has on calorific value. Source: Steve Sepp, eco-consult
-> To harmonze definitions and conversion factors for adequate data collection and estimation, the FAO has published a 'Unified Bioenergy Terminology' located here.[4]
