More than half of the world's populationthree billion peoplecooks their food indoors using open fires or rudimentary stoves. Indoor burning of solid fuels releases toxic pollutants including particulate matter and carbon monoxide. These harmful cooking practices cause an estimated 1.9 million premature deaths annually (Global Alliance for Clean Cookstoves, 2010). As the household members most likely to cook family meals, women and children are most affected. The reliance on biomass fuels in developing nations has put considerable pressure not just on the safety of families, but on the environment as well, increasing both deforestation and greenhouse gas emissions.
In Sudan's war-torn region of Darfur, women must walk for hours to find firewood, risking attack every step of the way. In 2005, the U.S. government asked Dr. Ashok Gadgil, Deputy of Lawrence Berkeley National Lab's Energy Technologies Area, for a solution to this grave problem. His team designed a fuel-efficient cookstove which is tailored to Darfur's climate and cooking. The Berkeley-Darfur Stove requires less than half the fuel of traditional cooking methods, decreasing women's exposure to violence while collecting firewood and their need to trade food rations for fuel. (2011 BERC Symposium poster)
Building on this work, the Lab has extended its cookstove research and development to other regions as part of a larger effort to develop affordable and appropriate technology for the world's poorest households.
Researchers use comparable quantities of firewood and food to compare the efficiency of improved cookstoves with the traditional cooking method in the majority of developing countries, the three-stone open fire. In each stove test, researchers cook a fixed quantity of food on a three stone fire and the improved cookstove to compare fuel usage between the two. Efficiency tests allow researchers to compare different design alterations to estimate impact, predict the reduction in firewood use, and determine the carbon emissions reductions that will result from substituting an improved cookstove for a three-stone open fire.
How much less wood does a Berkeley-Darfur Stove or Berkeley-Ethiopia Stove use than a three-stonefire?
Efficiency tests allow researchers to:
How much soot does the Berkeley-Darfur or Berkeley-Ethiopia Stove produce compared with the three-stone fire?
Reducing CO2 emissions: Each stove saves a little over 1.5 metric tons of CO2 per year. According to the US Environmental Protection Agency, the average US car (traveling 12,000 miles per year and getting 20 mpg) emits 5.2 metric tons of CO2 per year. With stoves lasting an average of 5 years, each stove in the field reduces more CO2 emissions than removing an average US car off the road for an entire year.
How much are the stoves being used and how efficiently are the cooks feeding the firewood?
How can we optimize how fast the stove gets hot?
What portion of the heating energy in the wood is transferred to the pot?
Supported through a Federal doctoral fellowship, graduate student Jennifer Jones is working to incorporate computer generated stove modeling into stove design testing. Most stove literature to date has focused on experimental testing on stoves to learn about stove performance to obtain necessary data. We are excited to launch this new component to our work and hope to build a computational stove model that guides stove design and can be used to determine tradeoffs between increased stove efficiency and reduced emissions.
Copyright 2015 Lawrence Berkeley National Laboratory.