Summer of Stoves (1/3)

Background

In June of 2010 I flew out of Portland, Oregon on a one-way ticket to Mexico City.  I bought a one-way ticket, not because I was planning on staying in Mexico forever, but rather because I didn’t know at the time when I was going to return or from where exactly I would be returning.  I was just finishing up my first year of graduate school at Humboldt State University.  The program I was enrolled in is called Energy Technology and Policy (formerly Energy Environment and Society) within the Environmental Systems graduate program in the Environmental Resources Engineering Department.  Students in this program have diverse backgrounds and interests, but all share an interest in issues related to energy.  My personal interest is in appropriate technology solutions for vulnerable populations in the global south with a particular focus on obstacles to scaling up dissemination of these technologies to the people who need them.  In simple terms, if these technological solutions are available and worthwhile, when then are they not being spread around the world like wildfire?  What are the barriers to bringing these technologies to more people?   With that in mind I developed a strong interest in pursuing one particular technology, improved biomass cookstoves.  Currently 50% of the world still relies on biomass as their primary household fuel source; wood, charcoal, dung, grass among others.  For these roughly 3 billion people, improved cookstoves can have a major impact on quality of life.

In June when I arrived in Mexico City I began what would be 2 months of intense research into everything related to cookstoves, from design principles, to testing methodologies, to dissemination strategies.  Over the course of the summer I visited 10 dissemination programs, conducted dozens of interviews of key players, stove users and program directors as well as conducted a random survey of household energy use patterns with a focus on individual perceptions of the issues surrounding cookstoves.

Patzcuaro, Michoacan, June 1-15

After landing in Mexico City I went straight to Patzcuaro, Michoacan.  There I spent 15 days working with and learning from the Interdisciplinary Group on Appropriate Rural Technologies (GIRA).  GIRA is one of the big players in the world of cookstoves.  Every year they, in partnership with the Autonomous University of Mexico in Morelia, UC Berkeley, and UC Irvine, publish journal articles focused on the cutting edge issues related to cookstoves.  The Patsari Cookstove dissemination program managed by GIRA is part of a new generation of cookstove programs. Having learned from previous programs’ successes and failures, the Patsari Project aims to address a range of complementary issues including: conservation of forest resources, improving indoor air quality, reducing household expenditures on fuel,  and reducing the global impacts resulting from the emissions of greenhouse gases and black carbon.  Their director is Dr. Victor Berrueta and the founder of the organization is the guru of stove programs in Mexico, Dr. Omar Masera.

On our way to repair Patsaris.  Tirian in the foreground with Ruben and Ramiro in the back.

On our way to repair Patsaris. Tirian in the foreground with Ruben and Ramiro in the back.

At GIRA I spent my first several days shadowing a team of stove technicians as they visited households that had received the first generation Patsari Cookstove. The first day I met the stove techs Felix, Ramiro, Ruben the engineer in charge Ebaristo at the field laboratory factory in the morning.  Ramiro is the most tenured stove builder who has been building stoves since the 1993, first starting with the Lorena stove.  Felix has 7 years of stove building experience.  We loaded up into the office truck and drove about 40 km outside of the town of Patzcuaro until we reached a village called Chihuerio where GIRA had installed 70-80 stoves.  I shadowed Ruben and Ramiro as they visited houses making repairs on stoves that were installed 5 years earlier.  Since that time improvements have been made to the design of the Patsari and the objective of this field work was to essentially bring the older stoves up to current design standards.  This is one of the distinguishing characteristics of GIRA.  In the eyes of GIRA, Victor Berrueta and Omar Masera, stove dissemination does not end with a stove being built in a home; that is when it begins.  Follow up is just as important as building stoves.  Their point is that without follow up, there is no way to measure the actual success of your program and therefore there is no evolution and adaption to accommodate the needs of the program beneficiaries.  Furthermore, stove adoption is an intimate process that takes place in one of the most sacred places in the world, the kitchen.  Without follow up programs, stove dissemination programs have no way to listen to the feedback of the most important constituent, the cook.  This is where GIRA excels.  For each stove they have built, they have conducted organized user feedback surveys.  According to GIRA this has been a cornerstone of their dissemination model.

Prototype Patsari with a custom clay and horse manure top coat.

Prototype Patsari with a custom clay and horse manure top coat.

Upon entering the first house I could see that it was a slightly different design than the Patsaris that I had seen previously.  Ruben and Ramiro informed me that this was one of the first prototypes, made completely of mud.  It was obvious that Rosa Elena, the homeowner, was proud of her new stove.  She had made modifications including adding a new top coat of mud combined with horse manure that gave it a smooth soft finish with the brownish orange color of the earth.  She was clearly happy to see us and immediately told us the problems she was having: smoke comes out the front, it’s difficult to light, and sometimes it goes out, she said.   Ruben and Ramiro were not surprised and had in fact anticipated these issues and were equipped with all the necessary materials to make the needed repairs.

They took apart the top of the Patsari and added fabricated bricks with holes between the comal and the secondary comales in order to maintain constant cross sectional area throughout.  They added a new prefabricated chimney base that has larger entrance holes than the previous to facilitate cleaning. Finally they added a brick in the back of combustion chamber to act as a baffle to direct the hot gases towards the front of the comal and to reduce the overall volume of the chamber and thus fuel consumption.  After making the repairs and modifications they sealed the comales back in with a new layer of clay.

Rosa Elena lighting her repaired Patsari.

Rosa Elena lighting her repaired Patsari.

After the repairs were made, Rosa Elena was allowed to immediately try out her modified stove.  After lighting it she commented that she wasn’t sure if it was lit because usually some smoke comes out the front when it is getting started.  In other words, it had been repaired.  Smoke coming out the front is likely a result of having too small tunnels connecting the combustion chamber to the secondary burners and the secondary burners to the chimney.  Both of these passages were standardized with the new brick and prefabricated chimney base.

What I noticed in Rosa Elena’s kitchen, and later observed in many other kitchens throughout Michoacan, was that she had many distinct cooking technologies in her tiny home, she likes to have cooking options.  Besides the Patsari, she had a clay wood fired bread oven, a microwave, a gas range as well as a barbeque outside.

Rosa Elena's clay bread oven.

Rosa Elena's clay bread oven.

What was clearly missing from her house was the extremely inefficient but surprisingly common “open fire.”  Even with this impressively wide range of options, it was clear that she spent the majority of her time cooking with the Patsari.  Of course this is because the Patsari has been designed specifically for women like Rosa Elena who spend the majority of their cooking time dedicated to making tortillas, beans and soups.  She told me she makes at least 20 pounds of tortillas each week on her Patsari.

I asked Rosa Elena a few questions:

Me: Before you had the Patsari, what was your primary means of cooking?

Rosa Elena: I used an open fire in my kitchen.

Rosa Elena with her newly repaired Patsari.

Rosa Elena with her newly repaired Patsari.

Me:  In comparison to before, using the open fire, how much fuel would you say you use now with your Patsari?

Rosa Elena: I use about half as much now.

Me: Where do you get your wood?

Rosa Elena: They bring it here from the forest and I buy it.  It is from the dead branches they find in the forest.  They cut them into pieces and bring them here.

Me: For your Patsari, how do you know when the chimney needs to be clean?

Rosa Elena: When smoke comes out of the front of the stove.

Taco vendor in Plaza Chica.

Taco vendor in Plaza Chica.

After a day of shadowing the stove technician team around I was exhausted.  But I was in Patzcauro and could not simply go back to my posada without at least a little exploring.  I knew Patzcauro was famous for its bustling market place and I had heard that the casual wanderer will find themselves encountering dozens of new foods to try, not to mention a myriad of crafts hand-made by the vibrant local culture.  I spent a few hours walking around, taking in the new smells and sounds of life in a classically central Mexican pueblo magico.

The next day I went to GIRA’s field office, located 10 miles outside of Patzcuaro.  There I found Brenda Vertiz, industrial design engineer intern, just getting started with some tests on a series of Patsari stoves that were located in the lab.

Brenda Vertiz, industrial design engineer intern at GIRA, demonstrating the heat distribution test.

Brenda Vertiz, industrial design engineer intern at GIRA, demonstrating the heat distribution test.

She was happy to train me on a newly developed testing methodology that was designed to characterize the distribution of heat across the cooking surfaces of the stove.  The Heat Distribution Test, designed by GIRA, measures the surface temperatures at specific points on the stove.

Heat Distribution Test

Heat distribution is an important measure of stove performance. The distribution of heat across a stove cooking surfaces will determine what types of food can be prepared simultaneously. An ideal distribution of heat cannot be defined because it depends to a large extent on the preferences of the user. However, with respect to the Patsari Cookstove, users in Michoacan, Mexico have observed that when the primary comal is at optimal tortilla cooking temperature, the secondary comales do not have enough heat to boil water. Some users complained about this while other users said they like being able to use the secondary comales as warmers while they are cooking tortillas. Conversely, when the secondary comales are hot enough to boil water, the primary comal is too hot to cook tortillas. Although this may be a limitation with the stove design that has optimized for efficiency of fuel consumption rather than maximum heat distribution, it is nevertheless an example of why this is an important metric for understanding stove performance. There may be a tradeoff between efficiency and heat distribution, wherein more efficient stoves tend to have less uniform distribution of heat. This possible relationship is something that is being investigated by GIRA and is part of the reason why there is interest in a heat distribution test for cookstoves.

Prefabrication and the standardization of Patsari building

Prefabricated Patsari components in the field office of GIRA.

Prefabricated Patsari components in the field office of GIRA.

An ongoing project at the GIRA field office is an effort to standardize the building process as much as possible.  The first versions of the Patsari relied completely on the technician with limited success.  Studies found a wide range performance, with some stoves functioning quite well and others rather poorly.  The reason for this is that the Patsari, while simple and elegant looking from the outside, has been highly engineered on the inside.  Combustion chamber dimensions must be closely adhered to, ramps below the secondary comales must have precisely the right contour, and gaps below the comales must be exactly 2 cm.  Even slight variations in these key parameters can lead to lower combustion efficiencies, smoke coming out the front, or worse, the stove simply not working at all.  The first solution was to build molds and to use as many prefabricated parts as possible.  All new Patsaris are now built with molds that help to decrease the variation in these parameters between stoves.  The construction process however, still requires a skilled technician with a background and understanding in stoves.  GIRA is now working with local tile manufacturers to develop a prefabricated stove top that essentially eliminates the dependency on stove technicians for achieving optimal stove performance.  The hope is that these prefabricated components stoves can be assembled in the kitchen and stove performance will be standardized.

Cheranastico Village Visit with Ana, Ramiro and Ruben

A view of Eagle Mountain from a street in Cheranastico, Michoacan.

A view of Eagle Mountain from a street in Cheranastico, Michoacan.

On June 10th I accompanied a group of GIRA staff on a day of one-month follow up visits.  We left from the field office in the morning.  There were four of us, Ramiro and Felix, both stove builders, and Ana Berrueta, the wife of Victor who works with women’s groups.  She has extensive experience in facilitating community meeting and focus groups.  I was told we were heading to a town called Cheranatizikurhini, or (Cheranastico) for short.  Cheranastico is located high on the Meseta Purepecha.  The population of 5000 speaks primarily Purepecha, a distinct indigenous language of the pre-Colombian indigenous inhabitants of Michoacan.  Both Ramiro and Felix are indigenous Purepechans and are fluent in the language.  After driving for an hour and a half from Patzcuaro we arrived in Cheranastico and were met by GIRA’s local contact and community organizer Roselio Joaquin Lopez.  The objectives for the day were to check in with new stove recipients and see how they are doing with their new Patsaris.

Felex and Ana waiting for permission to enter a house to do an interview.

Felex and Ana waiting for permission to enter a house to do an interview.

One month earlier Ramiro and Felix had installed Patsaris in 10 houses, the first recipients of improved biomass cookstoves in the village.  The primary cooking method for the villagers is the open fire and GIRA is looking to change that.  Following our local guide we made a surprise visit to each stove recipient’s house.  This was in order to observe what their normal usage patterns are.  If we had scheduled the visits with the group of women then it is likely we would have discovered different situations upon arrival.  Ramiro and Felix had a short survey to fill out at each house called the “Ficha de Revision” or Review Index, a survey that they complete approximately one-month after stove installation.  Ana was doing open interviews with the stove users, asking them about their general impressions, obstacles and challenges they had been experiencing in the adoption process and giving out informational brochures with maintenance and usage instructions.

On the way back to Patzcuaro I asked the group what their overall impressions were of the stove adoption in the community.  They told me that overall the women that we encountered on this day were satisfied with their new stoves.  They reported average reduced fuel consumption of 50-75% while most of the “negative” user feedback was associated with the heat distribution on the cooking surfaces.  While some of the households were completely satisfied with lower temperature on the back burners, the majority explained to us that they would like the heat to be more evenly disbursed from front to back.  Anna asked each stove user about her challenges to switching from the open fire to the Patsari.  Without exception, each stove user reported that for the first 6-10 days they were burning their tortillas a common occurrence with new stove recipients.  This would continue until they realized that they needed half the amount of wood as before in order to accomplish the same task.  Each house reported that they no longer use their open fire for cooking.

Open fire being used to boil a pot of water while a Patsari stove sits idle in the background.

Open fire being used to boil a pot of water while a Patsari stove sits idle in the background.

However, based on our observations it was clear that two of the women were attempting to mislead us.  Based on the fact that at the time of the visit two of the women were currently cooking with an open fire in their kitchen while the Patsari sat idle in the corner, we were able to easily determine that they had not adopted the new stove yet.  In summary, according to the GIRA team, eight of ten stove recipients had adopted the new stove or were at least in the process of switching over.  Many of the users also reported that their friends, neighbors and family members wanted one too.

When we returned to Patzcuaro I was surprised by a massive street party where groups representing each nearby village were marching and dancing in colorful costumes each representing the culture of their own village life.  The holiday was Corpus Cristo Thursday and each community comes to Patzcuaro with dancers, musicians and small samples of the local products.  To give thanks to God for the previous year’s harvest and bounty, and to ensure a plentiful coming year, each community gives away miniature versions of their local crafts and products.

Local fishermen performing their traditional dance on Corpus Cristi.

Local fishermen performing their traditional dance on Corpus Cristi.

First there is a parade with music and dancing that traverses the central part of Patzcuaro.  Then when each village group arrives at the main square, Plaza Grande, they do one final dance and then throw their gifts out into the crowd.  Simultaneously local leaders and dignitaries are standing on the balconies of the municipal building throwing cheap plastic baskets down to the eager open hands of the participants.  It was quite a site to see.  I certainly was not standing on the side observing like a confused tourist.  I was out there in the crowd with extended arms, a cheesy grin on my face and grasping at flying trinkets.  In the end I was able to snag a woven reed sombrero that came flying in my direction.

Two days later I sadly had to leave Patzcuaro.  But my sadness was assuaged by my excitement about my next destination, San Cristobal de las Casas in the mountains of Chiapas.  I had a meeting scheduled with the Tania Gonzalez, project coordinator at Otros Mundos Chiapas.

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