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| − | [[GIZ HERA Cooking Energy Compendium|--> Back to Overview GIZ HERA Cooking Energy Compendium]] | + | |
| | + | [[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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| | + | -->{{#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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| | = Main Principles<br/> = | | = Main Principles<br/> = |
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| | Freshly collected firewood contains up to 50% water. This water not only has no heating value, it is also consuming 25 - 35% of the energy of the wood to remove the moisture within the cooking process. Hence, wet wood has a low power output and a low temperature. Smoke is the visible indication of this wasteful practice. | | Freshly collected firewood contains up to 50% water. This water not only has no heating value, it is also consuming 25 - 35% of the energy of the wood to remove the moisture within the cooking process. Hence, wet wood has a low power output and a low temperature. Smoke is the visible indication of this wasteful practice. |
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| | == Increase the Surface of the Firewood<br/> == | | == Increase the Surface of the Firewood<br/> == |
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| | Firewood does not burn as such. It is the gasses generated in the process of its decomposition. For it to decompose, the wood has to be heated. Thick pieces of wood require a lot of heat to reach these temperatures. Hence, it takes a lot of time until the wood burns efficiently. Smoke is an indication that the decomposition of the firewood has not yet progressed sufficiently. | | Firewood does not burn as such. It is the gasses generated in the process of its decomposition. For it to decompose, the wood has to be heated. Thick pieces of wood require a lot of heat to reach these temperatures. Hence, it takes a lot of time until the wood burns efficiently. Smoke is an indication that the decomposition of the firewood has not yet progressed sufficiently. |
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| − | '''Recommendation:''' | + | '''Recommendation:''' |
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| | Splitting the firewood does not only allow for a faster drying process. It also promotes a faster decomposition of the wood into woodgas. Hence less heat is wasted for the decomposition process and the fire is more efficient. | | Splitting the firewood does not only allow for a faster drying process. It also promotes a faster decomposition of the wood into woodgas. Hence less heat is wasted for the decomposition process and the fire is more efficient. |
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| | == Avoid Excess-wood in the Cooking Process<br/> == | | == Avoid Excess-wood in the Cooking Process<br/> == |
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| | *Wood and air compete for the same space in the reactor. If too much wood is added, there will be at one point not enough space left to supply the air required for the combustion process. | | *Wood and air compete for the same space in the reactor. If too much wood is added, there will be at one point not enough space left to supply the air required for the combustion process. |
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| | In most cooking processes we can distinguish high-power phases (e.g. to bring a cold pot to boiling point) and low-power phases (e.g. for keeping a hot pot at the boiling point = simmering). Inexperienced cooks tend to use a lot of wood in the stove all the time, regulating the heat transfer through modification of the distance between the pot and the stove. This is a very wasteful practice. | | In most cooking processes we can distinguish high-power phases (e.g. to bring a cold pot to boiling point) and low-power phases (e.g. for keeping a hot pot at the boiling point = simmering). Inexperienced cooks tend to use a lot of wood in the stove all the time, regulating the heat transfer through modification of the distance between the pot and the stove. This is a very wasteful practice. |
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| | == Extinguish Surplus Wood at the End of the Cooking Process<br/> == | | == Extinguish Surplus Wood at the End of the Cooking Process<br/> == |
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| | It is a common observation that wood is still burning in a stove after the cooking has been completed. This wood should be extinguished once the fire is no longer needed. This applies as well for any burning wood which is removed from the fire e.g. at the start of the simmering phase. | | It is a common observation that wood is still burning in a stove after the cooking has been completed. This wood should be extinguished once the fire is no longer needed. This applies as well for any burning wood which is removed from the fire e.g. at the start of the simmering phase. |
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| | + | These are fuel-specific recommendations for firewood, but they apply as well for other processed types of solid biomass. |
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| − | These are fuel-specific recommendations for firewood, but they apply as well for other processed types of solid biomass
| + | Find other recommendations on how to efficiently manage the cooking process |
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| − | -> [[Cooking_with_Non_Timber_Solid_Biomass_Fuels|Cooking With Non Timber Biomass Fuels]] | + | -> [[General Kitchen Management Practices|General Kitchen Management Practices]] |
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| − | Find other recommendations on how to efficiently manage the cooking process
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| − | -> [[General_Kitchen_Management_Practices|General Kitchen Management Practices]]
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| | = Further Information<br/> = | | = Further Information<br/> = |
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| − | '''Fact Sheet Firewood Management''' | + | '''Fact Sheet Firewood Management''' |
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| | This fact sheet is a compilation of energy-saving practices and was developed by the Integrated Food Security Project in Malawi. Every practice is explained in detail and addition is provided regarding the reasons of fuelwood savings and additional benefits. | | This fact sheet is a compilation of energy-saving practices and was developed by the Integrated Food Security Project in Malawi. Every practice is explained in detail and addition is provided regarding the reasons of fuelwood savings and additional benefits. |
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| − | | [[File:GTZ 2a FS firewood management 2010.pdf|RTENOTITLE]] | + | | [[File:GTZ 2a FS firewood management 2010.pdf|180px|RTENOTITLE]] |
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| | = References<br/> = | | = References<br/> = |
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| − | This article was originally published by [http://www.gtz.de/en/themen/12941.htm 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|Imprint]]. | + | 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|Imprint]]. |
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| | <references /> | | <references /> |
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| − | | + | [[#Main_Principles|Top of the page]] |
| − | [[Firewood management techniques#Main_principles|Top of the page]] | + | |
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| | [[GIZ HERA Cooking Energy Compendium|--> Back to Overview GIZ HERA Cooking Energy Compendium]] | | [[GIZ HERA Cooking Energy Compendium|--> Back to Overview GIZ HERA Cooking Energy Compendium]] |
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| − | [[Category:Cooking_Energy]] | + | {{#set: Hera category=Cooking Energy System}} |
| − | [[Category:Cooking_Energy_Compendium]] | + | |
| − | [[Category:GIZ]] | + | [[Category:Cooking_Energy_Compendium_(GIZ_HERA)]] |
| | + | [[Category:Firewood]] |
| | + | [[Category:Energy_Efficiency]] |
| | [[Category:Wood_Energy]] | | [[Category:Wood_Energy]] |
| | + | [[Category:Cooking_Energy]] |
Firewood is a valuable source of energy, whether it is collected or bought on the market. It involves financial or time resources of the household to obtain it. Even users of traditional cookstoves can save firewood by applying the following firewood management techniques. Clever firewood management can save approximately 20 - 30% of the total cooking fuel requirement.
Freshly collected firewood contains up to 50% water. This water not only has no heating value, it is also consuming 25 - 35% of the energy of the wood to remove the moisture within the cooking process. Hence, wet wood has a low power output and a low temperature. Smoke is the visible indication of this wasteful practice.
Firewood does not burn as such. It is the gasses generated in the process of its decomposition. For it to decompose, the wood has to be heated. Thick pieces of wood require a lot of heat to reach these temperatures. Hence, it takes a lot of time until the wood burns efficiently. Smoke is an indication that the decomposition of the firewood has not yet progressed sufficiently.
A wood-fire is fuel regulated. To increase the heat output, more fuel can be supplied to the combustion chamber. In short:
However, in any kind of stove with enclosed combustion chamber one can observe a point where this equation does come to its limits. Instead of an increase of heat, one can suddenly observe more smoke, a darker flame colour and less heat. There are several effects which can contribute to this observation:
In most cooking processes we can distinguish high-power phases (e.g. to bring a cold pot to boiling point) and low-power phases (e.g. for keeping a hot pot at the boiling point = simmering). Inexperienced cooks tend to use a lot of wood in the stove all the time, regulating the heat transfer through modification of the distance between the pot and the stove. This is a very wasteful practice.
It is a common observation that wood is still burning in a stove after the cooking has been completed. This wood should be extinguished once the fire is no longer needed. This applies as well for any burning wood which is removed from the fire e.g. at the start of the simmering phase.
These are fuel-specific recommendations for firewood, but they apply as well for other processed types of solid biomass.
