Cooking with Solar Electricity

– Cooking with Solar Electricity –


How can we apply a successful project to a community in another part of the world?
Last year, a group from Cal Poly designed and tested a solar powered cook stove as a part of an appropriate technology class. These students went on to apply for and receive a grant to travel to Uganda to work on actually implementing this stove in a real community that needed it. Their goal was to create the stove with resources that were readily available in that specific community in Uganda. The stove uses a relatively low-wattage solar panel to power an insulated stove. Once in the community, they explored the possible resources and re-designed the cook stove to use these materials. The group successfully implemented multiple stoves. However, the materials that they used were very specific to the community. Our group from the Fall 2016 Appropriate Technology: Development class asked ourselves:
“How could this design be implemented in different communities? How would it be adapted to fit the needs and resources of a community in a different part of the world?”

We chose the community of Teococuilco de Marcos Perez in Oaxaca, Mexico. One of our group members has family who reside there, giving us a solid connection to the community. In this community, many people use biomass fuels, such as wood, to cook with. While this has been tradition for thousands of years, using these stoves has led to numerous lung and eye problems due to the smoke and lack of ventilation in the houses. Recently, the Mexican government has implemented Deforestation Laws that have led to a severe limitation on the amount of wood community members can use. Therefore, we propose implementing Solar Powered Cook Stoves to not only decrease deforestation, but also to reduce the health risks associated with excessive smoke.

We believe that due to the steady decrease in solar panel prices, which are being cut in half every five years, this project could be monetarily feasible, and will be increasingly affordable in the coming years. In addition, it would allow for the community to harness the solar energy that abundantly exists in their environment. To help us with this project, we will be in contact with two former Cal Poly students who helped implement solar cook stoves in Uganda. We will look to them for assistance as we believe they will be able to provide valuable insight through their real-life experience in this project.

-Teococuilco de Marcos Perez, Oaxaca, Mexico-


map_of_mexico editted.jpg

Community Information

  • General Information:
  • Rural community in the south of Mexico about 21 miles away from the area’s major city, Oaxaca (
  • People use a wide range of stoves, but the traditional biomass stove is the most common.
  • Recently people have been confronted with problems with biomass stoves because of newly implemented deforestation laws, which make fuel harder to come by and more expensive.
  • To fix this problem, the government has handed out new stoves that burn less fuel, but these stoves have largely not been adopted. This could be based on the fact that the government did not help install or give much information on the stoves, so the residents of this community were rather unsure on how to use and install them.
  • The failure of these government stoves give us the chance to see where they went wrong, and make sure our stove addresses these failures.
  • Climate Information:
  • Relatively stable temperature throughout the year.
  • Climate is a tropical savanna- meaning it is both humid and hot.
  • These conditions of nearly consistent sunlight are ideal for a solar stove.


  • Demographics
  • Population density: 49 people per square mile.
  • Typical living situation: a grouping of houses in the same close area that house an extended family.
  • Population: 1,106 residents

Due to the very little information available about Teococuilco de Marcos Perez, we decided to talk about the Oaxaca state as a whole, which the pueblo belongs to.

  • Oaxaca is the 2nd poorest state in Mexico
  • Per Capita Income: $3,400 (USD) compared to $20,000 (USD) in Mexico City
  • 76% of its population live in extreme poverty (lack food, water, education, healthcare)
  • Contains 33% of the Mexican Indigenous population (who are extremely marginalized and often have less economic opportunities)
    • Lack of healthcare
  • 1 hospital bed/ 1000 residents
  • 10.3% infant mortality rate
  • Life expectancy in Oaxaca as of 2013: 72.5 years
  • 22% of population is illiterate.

-Gapminder Graphs-
This graph shows how Mexico compares to other countries in terms of GDP/Capita and Life expectancy. The size of each country’s bubble represents
the country’s Co2 emissions/capita. It is important to note that in Oaxaca, GDP/capita is much lower at just 3,400 USD.

gap 2.PNG
In this graph we see how Mexico stacks up with the rest of the world in terms of GDP/Capita and Child Mortality rate. The size of the bubble in this graph corresponds to the country’s total population.



-SWOT Analysis

    • Strengths
  • Educates the community on the dangers of smoke inhalation
  • Dramatically cuts Cost- The main cost of Solar Cookstoves comes from the creation of the stove, which is now less then $100. Once the stove has been implemented, there are no additional costs to use electricity. Electricity prices in Oaxaca average around $.132 USD per KW (you mean kWh, kiloWatt-Hour). We calculated that for an average 1000 watt stove, with a family that cooked for 2 hours each day- the annual cost would be a little less than 100$. For a family that makes much less than $4000 annually, this energy price is too high.

  • Reduces environmental impact (look up how much carbon footprint decreases)
  • Complies with local deforestation lawsTakes longer to cook food- however, the solar cooker could be used similarly to a slow cooker where the food can be cooked all day and be ready in the evening.
    • Weakness
  • The taste of food will be different
  • It will take time to adapt to the new technology. Denise’s Grandmother mentioned that she thought the idea was crazy. However, we hope that through education about the health hazards of indoor pollution and education about how the technology works, more people may be willing to try cooking with these stoves.The stoves the government has implemented has not been appropriate for the community, therefore (??)
    • Opportunities
  • The lack of available healthcare means that many may have died from smoke related diseases without knowledge. Therefore, we have an opportunity to illustrate how the smoke can have an effect, and hopefully change someone’s view
  • The community is extremely unhappy with the government provided stoves- therefore we have a valuable opportunity to present new technology
  • Mexico is rapidly transitioning to the use of solar energy. It is estimated that the use of solar energy will increase by 562% by 2016 (560% over what year?)
    . Our solar cooker would be able to fit in very well with an emerging market.

    • Threats
  • Influential Community members/Church leaders that are resistant to the idea of solar cookers. They could have a very large impact on whether or not people would be willing to try the cookstove.

-What are the Problems We Need to Address?-

  • Currently 4 Million People die of Smoke Inhalation annually throughout the world.
  • This community mainly cooks with biomass cook stoves indoors, with no ventilation, causing significant lung damage.
  • The majority of the cooking is done early morning before work and in the evening after sunset, meaning that sunlight is often not available.
  • How to make sure the stove can heat food efficiently and can cook all types of food.
  • We hope that the use of a solar cook stove can lower the risk of lung damage and environmental impact.


How do appropriate Solar Stoves Operate?

  • Solar cookers use few materials: solar panel, insulation chamber, and electric heater.
  • Solar panels collect solar energy and convert it to electrical energy.
  • The electricity is ran


through and thin wire with a high resistance.

  • The high resistance creates more power

(turns electrical energy to heat)

, thus releasing more heat.

  • The wire stored in a metal container so that the heat reflects off the bottom and then have it sealed so that it heats the material on top.

(not necessary. If you insulate the chamber, the heat won’t leave)


  • The electric heater that was created is placed in an insulation chamber that is very thick so that less heat escapes to the environment.
  • Place what you want to cook in the insulation chamber to be cooked.
    • What have we adapted for the community?
  • The insulation chamber and stove will be made from the Regosol soil found in the community. This soil is made of deposits of sand and clay which is a very good heat insulator.
  • In addition, many people sell and grow corn in the pueblo. Corn husks can take up to 446 F°, and could be used as an insulator. Using corn would also be beneficial to the local economy.


-Cost Breakdown-

  • 100 watt solar panel in Oaxaca costs about $50
  • Wires: Wires are relatively cheap and easily available.
  • Corn husks: quite cheap. Normally used as a material to make tamales, so they are very readily available.
  • Total Cost: We estimate that in total, a 100 watt solar panel will cost less than $100 USD.

    (likely it will cost less than $5 more than the solar panels. I would estimate it to be around $55 now)

-Does this Stove Meet the Requirements?-
1. Is it easy to use?

  • While this stove is not as easy as traditional stoves, it is very simple to learn how to use it. Residents should have no trouble learning to use it.

2. Can it cook all foods?

  • Because the solar panel used is relatively low-wattage to keep costs down, it mimics more so the heat and power of a slowcooker. This type of stove is excellent for cooking certain types of meats and grains, because the food can be placed in the stove and left unattended to slowcook. However, food preparation that requires a lot of heat, such a grilling or frying, could not be done on this stove. Perhaps we could find a way to work around this but at the current design this would be a problem.
  • Many of the community residents use large pots for cooking, as they often make meals for a relatively large amount of people. These large pots don’t fit on the stove. Perhaps we could create a bigger-scaled stove to fix this problem. We could possibly provide two different stove sizes based on the individual’s needs. This would require some design work.
  • The stove is very efficient in heating water, and could be excellent for cooking rice or beans.

3. Is it mechanically effective?

  • At the current solar panel, the wattage is very low and it doesn’t give off very much heat. This could be solved by buying a higher-powered solar panel. Since solar panel prices are falling, a higher powered solar panel could really improve this issue. The implementation of a battery system (to store the energy), would increase the price, but could solve the problem of cooking early in the morning before the sun rises and at night after it sets.

4. Does it save fuel and burn efficiently?

  • These stoves should cause a significant decrease in fuel consumption, which would greatly help save money. Carbon monoxide

    (and CO2 and soot… the soot is carcenogenic and also a greenhouse gas because it turns the atmosphere black, which absorbs more sunlight)

    emissions would also decrease due to this stove.

5. Is it durable?

  • The stove itself isn’t incredible durable, but it’s very fixable. In Uganda, many of the families given the cook stoves were able to easily modify it to improve it. They mudded around the outside to improve insulation. This ability to be modified is a great quality. However, if the wiring comes undone, this could present a bit of a problem, since soldering is a bit more difficult.

    (should not be a problem. Actually, soldering is not necessary.)

  • However, soldering irons are quite cheap and can be bought for around $5-$10. Perhaps we could provide one member of the community with a soldering iron and materials and train them on how to repair the stove. He or she could be the designated reapairperson


    for the community’s stoves. Wires can also be bolted together to fix issues. If bolting wires is easier, we could train one member of the community on how to repair stoves in this fashion.

6. Non-cooking needs

  • This stove would be very useful for heating water. Usually the community wouldn’t spend the money to buy fuel to heat water, so this could be a big help in their lives. When the stove is not in use for cooking, heating water is a great alternative. If it seems the stove is mostly being used to heat water, we could buy black metal cans to fill with water and place in the sun during the day to heat the water. This way, the stove would not be “wasted” on heating water, and could be used primarily for cooking.


-Stakeholder Analysis-

  1. Members of the Community: Their health and general well-being may be dependent on this project. With the implementation of this project, community members’ health may improve. We believe that the effect of this project on the community’s interests will be positive. This stakeholder is the most important entity in the success of this project, because they will be the deciding factor on whether they would like to use the solar cookers. Lastly, the community members will have a large amount of influence on the solar cook stoves, because other members may follow their lead in utilizing the cookers.
  2. Church Leaders: While church leaders may not have interests at stake in the cook stoves, they could have a large impact on the success of the project. These leaders have a large influences in communities and could either influence people to use the cook stoves or to not.
  3. The Government: There may be a conflict of interest for the government to be working with our project. The Mexican government has already implemented new stoves in Teococuilco and may not be so happy with our project. However, they also may be appreciative of our solar design because it would decrease the need for biomass fuels, and further reduce deforestation. The government would have the greatest impact on whether the project could even be started in the community. Since they give their stoves away for free, it would not be taking money from them. we believe they would welcome our design, as it helps residents deal with the new deforestation laws. In addition, the Mexican government has been trying to increase use of solar energy. Due to this transition, they may welcome our efforts.
  4. Elders: In Teococuilco, elders are extremely respected. Therefore, their opinions on the solar cookers will be extremely important. We believe that if we explain the health risks associated with smoke, the elders would be supportive.
  5. Council: The council is a group of elected members from the community of Teococuilco. They are responsible for overseeing the pueblo and making decisions. The council would be responsible in deciding if the solar cookers would be appropriate for the community. We believe they would be interested in our idea mainly because they have had major problems with the government stoves.
  6. Doctor: The doctor in the pueblo, known as “The Doctor” is a trained physician that now lives in Teococuilco. He is also a very respected member of the community. Because he does understand the health risks associated with indoor cooking, he would be a major asset in making sure this project succeeds.

The community we explored definitely has a need for a solar powered cook stove. Deforestation laws and poorly-implemented government stoves have left this community in a unique place of need. Though we have foreseen problems with the stove, namely that it will not be able to fully replace a tradition stove in all its functions, we have hope for this stove. With rapidly improving solar technology, many of the problems our stove faces today could be obsolete in a very short amount of time. Solar panels are decreasing in price very quickly, and in a couple short years we could be able to buy a much more powerful solar panel for the same amount we are spending on a low-wattage one today.

A higher powered panel could completely revolutionize our stove, eliminating the problems we see with it today. A stove that heats up quicker and cooks hotter has to potential to completely replace a traditional biomass stove.

The design of this stove has incredible potential. Paired with a more powerful solar panel, the possibilities are endless.

(maybe an exaggeration?)

We believe these stoves could be successfully implemented in the community and greatly improve the lives of the residents if a higher-wattage solar panel is used.

About Us:
Aditi Vepa- Third year Business Administration major with an Information Systems concentration. I am extremely interested in seeing how our different interests and perspectives can tie into the Solar Cookers project.

  • Contact Information:

Denise Garcia- Liberal Arts and Engineering Studies major with an STS minor in Media Arts, Society, and Technology with concentrations in Computer Graphics and Graphic/Web Design. I am interested in the application of these stoves in other places and how they can be further developed to apply to other communities. (Note: Denise’s family comes from the community we chose, and many of her extended family still live there. Her connections and insight have been invaluable in our project).

Kalena HermesSecond year Modern Languages major (Spanish & French). I am excited to see how this project could change the lives and health of people beyond Uganda, and how my Liberal Arts background can be applied to this project.

  • Contact Information:

Nick Crawford-Third year Mathematics major with a Pure concentration and physics minor. I am really interested in how to make these stoves applicable to all different environments and situations.

Nick Wagner- Third year Economics major. I am looking forward to learning more about how these stoves work and how we can use them to help people all over the world.