Sunday, May 25, 2014

From Traditional to Modern Stoves: A Chronology of Development


By Doug Barnes

India Traditional Stove: Credit C. Carnemark
Recently I participated in a very interesting workshop at Yale University. The workshop was called The Adoption Gap: Design, Development and Diusion of Household Energy Technologies. The focus of the conference was to examine why improved biomass cooking stoves have not achieved widespread adoption even after over 25 years of promotion. Many of the presentations were very innovative. Included among the speakers was Rema Hanna, who is the author of the controversial study Up in Smoke. She talked about her well designed stove impact assessment. Unfortunately, the stove being evaluated was from India's legacy mud stove program, some of which are still being promoted. Hanna made the valid point that many current programs are still supporting such stoves. While this is true, today there are many  better designed stoves compared to those from the 1990s (see commentary on the paper). Unfortunately, public monitoring and evaluation studies of these new stoves are still fairly sparse. The presentations from the conference are not yet available on line, but I will update this blog once they become available.
Fortunately or unfortunately, I am one of a small number of people that have been involved in improved stove development for almost its entire history. I say fortunately because it has been a very interesting to observe the evolution of the programs over the years. I say unfortunately, because even today with the many innovations taking place, most poor households in developing countries still use open fires or primitive stoves for cooking.  Also, in many countries well meaning non-governmental organizations are still promoting the stoves designed in the 1990s.
I prepared a presentation for the conferences with the title, Improved Stoves:  What Have We Learned, How Do We Move Forward? The ideas for this presentation were taken from my recent book Cleaner Hearths, Better Homes: New Stoves for India and the Developing World. For those interested, a free digital copy of the book is available, or for those more interested in print, copies can be purchased online. The book describes the positive and negative aspects of India's legacy improved stove program that was abandoned in 2002. This legacy program now is universally criticized, but most people really don't understand the pros and cons of the old program. Some aspects of the legacy stove program were quite innovative, including working with NGOs, including women's groups, assigning technical agencies to evaluate design issues, and developing commercialization strategies. Many of these innovations are relevant for the promotion and sale of improved stoves today. 
As part of my presentation, I had one slide on the development of stove programs. For those just now becoming interested in the new stoves, this slide provides a historical overview of the 25 year history of improved stoves.  The text below the break is from a glossy insert in the center of Cleaner Hearths: Better Homes that was published in 2012. The rest of the book is based on empirical findings from short questionnaires and focus discussion groups carried out at the very end of India's program. The book takes a more objective approach identifying both what went wrong and also positive contributions of the program for people in India. Anyway, continue after the break to read my short history of improved stoves.

A Short History of Improved Stoves
Stoves have existed since the beginning of human history.  They have come in various sizes and styles, having been adapted to myriad cultures and food preparation methods.  As society has progressed, more sophisticated stove models have been developed.  Today’s modern kitchen reflects the many types of standardized and specialized cooking devices available, from coffee and tea pots to toasters and gas cooktops. 
In developing countries, the pattern of stoves development has ranged from traditional stoves to gas or LPG.  Over the last 30 years, various programs have promoted improved stoves as a bridge between traditional and modern ones.  The development of better stoves has witnessed several overlapping stages, which are chronicled below.
Traditional Stoves
Traditional stoves have been around for thousands of years.  Users often make the stoves, customizing them to preferred cooking styles.  In South Asia, traditional stoves are commonly made of mud, but many households use three-stone, open-fire stoves.  It is common practice in South Asia to use straw, leaves, and dung as cooking fuel.  The outdoor stove at left is being fed small twigs.  Such fuels require constant attention.
Unless the kitchen is well-ventilated or the stove is located outdoors, cooks are exposed to massive amounts of smoke emissions.  Even outdoor stoves may expose cooks to high levels of pollution.  Stove efficiency varies widely, depending on use, ranging from 10 to 20 percent.  The indoor stove at the beginning of the blog uses small blocks of wood.  The black substance visible on the back wall is tar, the product of incomplete combustion.  Carbon also covers pots and pans, making them difficult to clean. 

First Generation: Custom Built
At the outset, India’s National Program on Improved Chulhas focused on producing and disseminating stoves that the poorest households could afford.  With the exception of the chimney, these first-generation stoves were made of mud and clay, as illustrated by the Parvati stove .  Indentations in the pot opening helped to channel heat around the pan and prevent smoke from entering the kitchen.  From 1980 until about 2002, hundreds of such models were developed.  As one might imagine, with repeated heating and cooling, these stoves easily cracked and degraded.  The estimated two-year life span proved too optimistic; in practice, most stoves failed within a year. 

Lorena Original 2
Rare Photo of Original Lorena Stove by M. Tay.
The Lorena stove, whose name is derived from mud (lodo) and sand (arena)—the primary materials used to make the stove—was originally developed in Guatemala.  This picture, taken in the early 1980s, depicts one of the myriad models developed throughout that decade.  Popularity among Latin America’s nongovernmental organizations, governments, and donor agencies increased.  But use of varying sizes and low-quality construction materials reduced reliability, leading to user dissatisfaction.  Today the Lorena stove is only rarely produced in Latin America. 

Second Generation: Manufactured Components
In the 1990s and early 2000s, the trend to make stoves of more durable materials also made them more expensive.  In India, the Laxmi, like the first-generation Parvati, was originally made of mud.  But in the last years of the National Program, many stoves were constructed of cement or a mixture of clay and cement, which increased the cost.  With the exception of the stove pipe, these models were made from prefabricated molds.  But the efficacy of this approach was never proven because, only a few years after adopting it, stove dissemination under the National Program ended. 
Plancha Stove: Credit Fundacion Solar
In Latin America, the Plancha—so-named because of its prominent metal griddle (plancha)—was disseminated under Guatemala’s social fund program.  A more expensive, durable stove lasting 10 or more years, the Plancha has a metal top used for roasting corn and preparing tortillas and other staple foods, a shelf for feeding wood, space on top for placing cooking utensils and equipment, and a chimney for venting smoke.  For local communities, who had other development options under the social fund program, the Plancha was a popular choice.  If a community decided on the stove option, then virtually every household  received a Plancha in return for contributions of labor and local materials.  The combination of having a durable stove along with many convenient features led to a high degree of popularity and continued stove use.
Third Generation: Manufactured Stoves