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ENERGIA News Issue 2.1, February 1998

Solar Baking Under the Sonoran Sun

Laurie Stone

Walk down almost any city street in Sonora, Mexico and you're likely to see bakeries filled with sweet breads, empanadas and Mexican cookies.

Ciudad Obregón is no different. In a small poor neighbourhood on the outskirts of Ciudad Obregón (a city of 400,000), a group of women have started their own bakery. Along the dirt roads of Aves del Castillo and under the heat of the Sonoran sun, this small group of women have started to make and sell their own breads and empanadas. Yet, these women are taking a different approach; they're baking with the sun.

Two years ago, Ken Olson and myself, both of Solar Energy International (SEI), had the pleasure of visiting Aves del Castillo. Through the Tucson based Farmer to Farmer organisation and the Sonoran branch of Save the Children (FAI) we were introduced to a woman's group called Mujeres Activas (Active Women). And active they are. These women from one of the poorest neighbourhoods of Ciudad Obregón, are overcoming their economic problems in innovative ways. With the help of FAI, Mujeres Activas have held nutrition clinics, started a programme to sell soy products, have learned to build straw-bale houses and have been building and cooking with solar ovens.

There is a great need for employment in Aves del Castillo. The women of Mujeres Activas were looking for a micro-enterprise that could help support their families. Of all the different micro-enterprise possibilities presented before them, they felt a solar bakery could best meet their needs. And having solar-cooked for their families for months, they were already hooked on the idea.

For the next two years, while we looked for funding, the women worked out their plan. They decided who would be involved, what they would bake and how they would advertise. With the help of the Tides, Greenville and International Foundations, SEI was able to return to Ciudad Obregón to help the women with the technical part of the project: the solar oven. Ed Eaton, Cholla Eaton (Ed's daughter and our trusty photographer), Laurie Loeb and I, all of Solar Energy International, headed down to Sonora, Mexico to meet the women involved in the bakery project, teach them to build commercial size solar ovens, and to try out numerous solar-baked Mexican pastries.

The oven

Ed had designed a large commercial size solar oven which we used to bake cookies at our local summer fair. With a few adjustments to the materials used and the angle of the glass, we had a great model for the bakery in Sonora, Mexico.

We built two ovens for the Aves del Castillo bakery. The first one was built at our office in Colorado. We made this oven into a kit, for easy assembly. It made it much simpler to teach all the steps involved in building the oven, while we helped the women assemble the kit. It also helped the second oven, which was built from scratch in Ciudad Obregón with local materials, come together quicker than we could have ever imagined.

Each oven is 76" x 34" to accommodate a standard size glass unit. They are made of : plywood and ductboard insulation. The double pane tempered glass is angled at 30E (the latitude of Ciudad Obregón is 28E). There are two side reflectors (40" x 42"), angled at 60E and a back reflector (76" x 42") which hinges, so that it can be put at any angle depending on the season and time of day. The reflectors are covered with EverbrightJ, a shiny aluminium foil. The ovens are divided in half, with a door on each back side. We have found, in our cookie baking experience, that using a fan to circulate the air does wonders for cookies and pastries. So we included two PV powered fans, one in each side of the oven. The fans are run by one 6 volt, 5 amp photovoltaic module.

The ovens are on stands with wheels on the bottom to accommodate easy tracking of the sun. A local carpenter built the stands along with an adjustable rack on each to hold the PV panel. When the ovens are not in use the panel folds down to keep it out of the way, and when it is in use, it can be tilted at varying angles.

Building the ovens couldn't have gone smoother. There are four women involved in the bakery, but on the first day of the oven building eight women showed up. They told us they weren't all part of the official bakery group but were eager to learn about building ovens. They asked us if they could help. We were ecstatic that more people wanted to learn about solar cooking. During the next few days many people stopped by to pick up a hammer, sketch out the oven plans, or just to watch this huge solar oven being built.

On the first day we hardly had time to pull out the tools before the women were hard at work. Their energy and enthusiasm made the first oven come together in a day and a half. We thought that building the second oven from scratch would take much longer. Yet the women knew exactly what to do, and were so eager to get the oven built they didn't want to stop working. One day after getting the main box put together and the insulation put in, we left for our lunch break. When we came back three hours later (the Mexicans like long lunch breaks to avoid working during the hottest part of the day), we were surprised to see that Rosalinda and Lupita had not even left for lunch. They had worked straight through, and both of the side reflectors were now on the oven. At that rate, it only took two days for the second oven to be ready for cooking.

Empanadas and more empanadas. . .

Now that the ovens were built, came the hard part; learning to run a business. The first thing that needed to be done was to test out all the recipes in the ovens. The next three days were spent making empanadas filled with squash or strawberry jam, cookies, breads, muffins, pizzas and coyotas (a Sonoran staple, a large flat pastry filled with brown sugar). We, of course, had to be the tasters to make sure all the recipes were up to par. They were all delicious! Every day the women also cooked lunch for everyone in the ovens, making rice, fish, pizza and steamed vegetables.

During those days, we also discussed the follow up to the project. We provided the women with a weekly form to be filled out. The forms were to be used for the women to keep records of the bakery, and for us to keep track of how the bakery was doing. The form asked questions such as:

• How many of each type of pastry or bread were made each day?
• How many customers did you have each day?
• How many people worked and how many hours were worked each day?
• How much money was spent on ingredients weekly?
• What was the weekly profit?
• What problems, if any, did you have with the oven?
• What new things were tried?

The women already had an advertising plan worked out. They hung up and handed out flyers throughout the neighbourhood and they advertised on the local radio station. Dora Elia, a woman working with FAI, taught some accounting. SEI provided the women with a loan to buy any baking equipment they might need such as bread pans and cookie trays. FAI provided them with a location for the bakery. Any profits they make, after they pay themselves a decent salary and pay off their loans, will be reinvested in the bakery to build more ovens, build a nicer space for the bakery or even expand to do a cafe. They are also thinking of building and selling smaller family size ovens to people in Aves del Castillo and neighbouring communities.

Solar baking significance

The bakery is now open for business. The women of the bakery are not only earning much needed salaries, they are also be spreading the word about solar cooking. Each day they have baked they have sold out of their baked goods. On an average day, they gross twice what they spend on baking ingredients. 10% of their earnings go to pay off the loan for the baking materials, and the rest is shared as salaries.

Micro-enterprises like the Aves del Castillo solar bakery have far reaching consequences. Now that the women are earning money, they say that their children can go to school, they can provide their families with shoes and clothes, and they don't have to worry about whether they will be able to put food on their plates.

This model micro-enterprise also has significance world wide. The women of Aves del Castillo have proven that with some will, determination and sunshine, people can improve their quality of life. There are people all over the world who could benefit from a solar business such as this bakery. Although most solar projects in developing countries focus on rural areas, there is also great need in the cities. Unemployment is high in many cities throughout the developing world. Often people from rural areas flock to the cities in search of employment, only to find themselves living on the streets with the rest of the unemployed. Reducing the appeal of urban life by bringing electricity to rural areas is one way solar energy can improve people's lives. But creating employment in cities is another way to better people's lives and should not be overlooked.

The Sonoran commercial size solar ovens will bake hundreds of empanadas and coyotas. However, there is much more to running a successful solar bakery than a hot solar oven. The enthusiasm, competence and devotion of these women are what will make Ciudad Obregón's (if not Mexico's) first solar bakery a huge success.

Laurie Stone teaches renewable energy technologies at SEI/USA. She has worked on numerous development projects throughout Latin America, installing photovoltaic systems in rural areas and training women in building and using solar ovens.

For more information, please contact:
Laurie Stone, Solar Energy International, P.O. Box 715, Carbondale, CO 81623, USA; Tel. +1.970.963.8855, Fax +1.970.963.8866, Email sei@solarenergy.org, http://www.solarenergy.org/sei

Cocinando con energía solar bajo el sol de Sonora

Laurie Stone

En Aves del Castillo, un barrio pobre en las afueras de la Ciudad de Obregón

(400,000 hab.) en Méjico, un grupo de mujeres ha comenzado a hacer y vender empanadas pero bajo una nueva propuesta; ellas hornean con energía solar. El grupo de “Mujeres Activas” con la ayuda del Energía Solar Internacional (SEI) construyó dos hornos calentados por energía solar. Uno de ellos fue traído a Méjico en partes para ser ensamblado, de esa manera al momento de ser armado las mujeres aprenderían su construcción y funcionamiento. El segundo horno, entonces, fue construído de una manera rápida y sin complicaciones en la Ciudad de Obregón con materiales de la localidad.

Una vez construidos los hornos vino la parte difícil; aprender a iniciar y llevar el negocio. Esto fue logrado a cabalidad mediante un plan de promoción, degustación y selección de productos. El éxito de la panadería en Aves del Castillo no solamente permite a las mujeres tener un salario respetable sino que también hace posible la difusión de la idea de cocinar con energía solar. Micro-empresas como esta panadería solar tienen consequencias de largo alcance. Las mujeres de Aves del Castillo con su fuerza de voluntad, determinación y entusiasmo han puesto en evidencia que la gente puede mejorar su calidad de vida.

Así mismo la gente a nivel mundial podría beneficiarse con empresas a base de energía solar no solamente en zonas rurales sino también, como lo demuestra esta experiencia, en zonas urbanas.