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
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 have been around for thousands of years. Users often make the stoves, customizing them to preferred cooking styles. In
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.
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.
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
Second Generation: Manufactured Components
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.
|Rare Photo of Original Lorena Stove by M. Tay.|
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|
Third Generation: Manufactured Stoves
|Justa Ecostove in Honduras: Credit E. Derby|
Another approach to manufacturing better stoves has been taken by companies such as Envirofit, International that make a wide variety of products for worldwide market. Envirofit International produces a line of cookstoves including portable wood, charcoal, and built-in designs. Their development was a result of a partnership with the Shell Foundation Breathing Spaces program, and requires all of their stoves to meet the industries’ most rigorous performance and emissions standards – largely possible through their patent-pending design and materials advances. The company mission is to achieve high sales volume and economies of scale by selling high-quality, low cost and durable stoves at a global level. Centralized production has allowed them to meet large initial demand in India and Africa, and they are pursuing localized assembly and production in key markets. The available 5-year warranty and approximately 30% efficiency levels make them attractive to carbon programs. The pricing for the stoves ranges from $15 to $30.
The Ecostove which is based on the rocket stove design was developed by a Nicaraguan nongovernmental organization called Proleña under the Pro-Tortilla program. The stove’s innovative combustion chamber design and chimney account for the removal of most smoke from the kitchen. More expensive than first- or second-generation stoves, the Ecostove sells for US$40–60. But because the stove lasts 5 or more years, the annual cost is comparable to that of a traditional mud stove. The challenge in these programs is to make the stove affordable through innovative financing to keep the monthly costs low.
Modern Fuels and Gasifier Stoves