“Application of textiles is not only confined within apparels and wearable anymore. The application of textiles and textile articles in various technical purposes are evident. But application of textiles in cooking to reduce energy consumption is a completely new idea which has been innovated by some researchers from Institute of Energy of University of Dhaka with the help of German based development organization GIZ. The author was a member of the team and he shares the properties of the textile E-bag and its cooking performance.”
A.K.M. Monjurul Haque, Lecturer,
National Institute of Textile Engineering and Research (NITER)
Introduction
The E-bag is a simple insulating technique to retain heat during cooking to reduce the amount of energy consumption. It is a standalone, non-electric insulated bag designed to reduce the amount of fuel required to cook food. Instead of being placed on a stove for the entire duration, food is heated to a boiling temperature and transferred to the cooker. It uses the principle of thermal insulation to continue the cooking process without requiring any additional heat. This cooker is an emerging solution to increase energy efficiency in the cooking process that employs the retained heat for cooking in a rural kitchen or elsewhere. All sorts of food items can be cooked in this cooker, including rice, potato, chicken, vegetables and beef etc. It also can be used as a cooker, hot-pot, ice-box and yogurt maker. The limitation of this bag is that it can be only used for cooking or boiling but nor frying.
Background
Cooking of most food item require application of heat which is obtained generally by burning various types of fuels in cooking stoves. Around 24 million households in rural areas and 5.8 million households in urban areas use biomass fuels for household cooking. The families in the urban area and the rural area alike have to pay for the fuel they use for cooking and this expenditure has a significant market share of their income. The cooking from commonly used open stoves is responsible for indoor air pollution causing severe health hazard for the women as well. According a study by WHO this hazard is responsible for 46,000 deaths every year in Bangladesh mostly children and women. In many rural areas, women have to walk a long distance to collect fire-woods for cooking. The collection of firewood also poses threat to the forest of deforestation leading to increase of greenhouse gas emission and acceleration of climate change impacts. However, the use of fire woods or fossil fuels cannot be eliminated from cooking especially when the rural areas are in concern. The detrimental effect of the wood burning to the environment and people’s health will remain as an insoluble issue unfortunately. But at least some relief can be attained if the use of fire-woods can be reduced to an extent. The E-bag is introduced to do the same. It is capable of reducing around 30% of the fire-works and the use of fire-woods for cooking daily food items.
E-bag’s insulation allows food to retain required cooking temperature, to continue passive cooking or keep warm while in the bag. Different types of cooking need different time duration to complete the cooking. E-Bag uses the principle of thermal insulation to continue cooking, and keeps food warm without needing additional heat energy. It is a hassle free cooking process because there is no need to plug in or control the heat of the stove to complete the cooking. The food never gets overcooked or burnt, because it is not placed on direct heat. So no fuss, no tension and no monitoring required.
Construction of the E-bag
E-bag looks like a hollowed bag with a separate bag lid and a draw string. The fabrication process of E-bag starts with collection of raw materials and other purchased items. The E-Bag consists of an inner layer of insulation containing recycled polystyrene balls or other insulation materials, with an outer, draw-string covering of poly-cotton textiles or other fabrics. The Concept of E-Bag is similar to the Thermal Cooking pots which has been available on the market since the 1990s. The benefit of the E-Bag is that in theory, it can work with various pot sizes as opposed to the traditional thermal cookers where a supplied pot is used.
Process of Cooking
The process of cooking using the E-bag is very simple. The E-bag cannot initiate the cooking by itself as it does not generate any heat and uses no energy. The pot of food have to be heated on a stove or any other cooking oven until it reaches the boiling point. After few minutes simmering the stove is put off and the pot is placed inside the E-bag. The pot must be kept inside the E-bag until the cooking is finished. Different items will require different cooking times in the E-bag. After the speculated time the pot have to be brought out from the E-bag and food can be readily served. The food in the E-bag is never over-cooked so the nutrition is reserved in the food whereas the continuous cooking under fire often reduces the vital vitamins and nutrients from the food. Due to slow cooking the food becomes tender, hygienic, tasty and easily digestible.
Benefits from E-bag
The E-bag is a simple insulating idea innovated for cooking. As it is not meant to generate any heat rather retains the heat generated from the pre-heat from the stove, the main idea is to increase the heat efficiency and reduce energy consumption. The benefits can be grouped as follows:
- Simple and easy cooking process
- Saves up-to 50% of the required cooking energy
- Can keep food or cold up to 10 hours
- Portable and safe
- Reduces stove time by two-third
- Cost effective
An investigation by GIZ estimated that every E-bag can save up to 1.7 trees, 1000 liters of water and 1250 hours of time spent in collecting fire wood. So the use of E-bag help immensely to conserve the environment if it can be made popular especially in the rural areas.
Conclusion
The E-bag project was patronized by GIZ who eventually marketed it with the name Wonder-bag in different countries of the world. It was an initiative under their Sustainable Energy Development (SED) program. They are supporting manufacturing organizations to develop their capacity and providing promotional support by training the stove users. The program is aimed to introduce at least 100,000 wonder-bags by 2018. GIZ has a plan to develop at least 10 manufacturers and distributors in Bangladesh. The bag is made with different compositions to examine the insulation power. Among the derivatives apart from the coconut fiber insulation showed lower heat retention compared to the polymer insulation ones. As the surge for energy is ever increasing in the world any small initiative to conserve it must be appreciated. The E-bag has a great potential to reduce energy usage in cooking hence can be termed as a great innovation.
Sources:
- ‘Retained Heat Cooker (RHC) Reduces Cooking Energy Consumption and Carbon Dioxide Emission’- GIZ Report
- ‘Reduction of Cooking Energy and CO2 Emission using Heater Retention Cooker Rice Cooking’- Paper Published in IEEExplore by Sayedus Salehin, A.K.M. Sadrul Islam and A.N.M. Zobayer
