CEDESOL Cocinando pollo con una cocina solar Cocinando pollo con una cocina solar, Cooking Chicken in a Solar Oven David Whitfield, CEDESOL, www.cedesol.org Bolivia maio de 2007 This short video starts out showing chicken cooking in it’s own juices. If you look closely you can see that the juices are slowly bubbling, not in the form of a hard boil most of us are used to but a slow roiling boil just the same.
The picture pans away and suddenly you see more chicken and before you realize it, you are looking at chicken inside of a solar box cooker. This picture shatters the myth that solar cookers don’t work, and shows that they can work very well!
As we look around in the video, notice the 2 blue baskets to the left. Freeze the picture there a moment. Those are an example of a home made retained heat cooker or thermal cooker. In all of our workshops and demonstrations we try to give away the thermal cooker technology. It is truly the lowest cost, quickest solution to reduce indoor air pollution and fuel consumption. Sadly it is also the hardest for most folks to develop the habit of using.
Next the earliest model of our 2-burner rocket stove comes back into view. Even though this is a solar cooker workshop, we demonstrate the efficient wood stove, because we know the solar cooker is not a stand-alone device. In the background you can hear hammering and a woman talking. She is saying that the 2-burner rocket stove they want too, but “in proyecto” which refers to the stove program with the GTZ subsidy. This video was made in June of 2006 when an ETHOS team came down to do their BOLIVIAN PROJECT jointly with Sobre la Roca (On the Rock), Ruth Whitfield’s small business. Last week CEDESOL signed contracts for 2 burner rocket stoves with around 40 people, many from this course.
Ana Maria, the girl in yellow now has her rocket stove she learned about a year ago while building her own solar cooker. Rosemary, the woman doing the talking in the background has had here solar cooker since 2003 and now she helps promote solar cooking whenever she can. She is pointing out to me that in one of the solar cookers someone is baking empanadas!
As Tom Miles has stated, CEDESOL promotes integrated cooking, defined as the combined use of efficient biomass, solar and retained heat technologies. We coined the term "ECOLOGICAL COOKERS”.
Years of working with stoves and solar cooking has helped have mature our attitudes so that long ago we abandoned the "one size fits all" solution mentality.
Solar cookers work, work very well and have the abilities to make a major contribution to the betterment of lives and reduce environmental degradation. Solar cookers are not the solution for every situation. Just like in the stove business, too often too many try to use a super low cost solution like the $5 cardboard box solar cooker and when it doesn't work as well as they thought, then "solar cooking doesn't work”.
Please take a moment to read the results of a master thesis, 6 months of investigations in the field here in Bolivia by an independent researcher. ---
Research was conducted in the central highlands of Bolivia in 2005 to assess the continuing impacts of solar cooking on participants of these solar cooking courses conducted by the Whitfield’s. The researcher, Chris Pell of the University College London, interviewed 170 people with and without solar cookers to determine whether their use affected household fuel consumption.
The data showed that 92.7% of the solar cooking course participants continue to use their solar cooker three to five years after the course ended. In fact, 62.4% of all participants use their solar cooker at least once a day during the dry season, demonstrating a lifestyle change that incorporates solar cooking into their daily lives.
The solar cooker now supplements their other energy sources: gas, wood, or a combination of gas and wood.
Solar cooking provides numerous advantages, including health, environmental, and economic benefits. For families in developing countries, the strongest of these may be the economic benefit of buying less fuel for their other cooking methods.
Pell found that there was a significant difference (at the 95% confidence level) of the monthly fuel expenditure per household between families with a solar cooker and those without one for those households that purchase but do not forage for their fuel wood. These families reduced their fuel expenses by 40.1% and 35.5% in the dry and wet seasons, respectively.
See: Lasting Impacts of a Solar Technology in Bolivia 2006 -----
Scientific collaborating data, which has been hard to come by.
Now, if market factors are also evidence,:
Just last week I spent 5 days in the rural municipality of Saipina (fotos to come later) where we had introduced about 100 - 2 burner rocket stoves with chimneys and around 50 solar cookers, depending on what the "client" wanted. While finishing up an interview and doing full set of water boiling tests and the CCT with members of a local university who contracted by GTZ to evaluate our work, the stove owner asked, "When will you bring more solar cookers?" "Now that we know our stove works like you said, we want a solar cooker too because our neighbor has one and they are really saving time and fuel".
In the context of this GTZ project the client chooses what device they want and of the 600 (+/-) devices delivered under this contract so far, 40% are solar cookers.
Let me repeat something important. Solar cookers are not THE solution and should not be purported to be. They must be utilized in the areas where they have advantage.
Bolivia is located between 15 and 20o South latitude and is in prime solar cooking location. On the other hand, Tom Sponhiem in Seattle Washington uses a HotPot solar cooker from April through October. Many of you heard a paper on the HotPot at the last ETHOS meeting. We use wooden box solar cookers with a sloped solar window. We have found that the box cooker can be used as a retained heat cooker when it is not possible to use it with sunlight and teach people to do so. Perhaps that is one reason we have such a high usage rate.
In India, they report 600,000 solar cookers in use. In China, a parabolic type is the preferred cooking method for nearly 2 million families.
Back in Bolivia, a French organization runs projects like ours (they learned from us) and have delivered several thousand solar cookers around Bolivia. (They also learned rocket and retained heat technology from us and exported it to their projects, along side the solar cookers to many African countries) Sobre la Roca has about 3,000 solar cookers delivered over the years.
At the recent Stoves and Solar cooker International Conference in La Paz, at least 30% of the people were solar cooker promoters. One organization claimed to have a demand they will be filling for 5000 solar cookers in the high plains area.
As chairman of the steering committee for Solar Cookers International Association, I get to hear about a lot of solar cooking and can assure all of you skeptics that solar cooking is maturing along with stove technology and many, many thousands around the world are currently using a completely non polluting energy source.
Now as to power or energy used to cook, cooking with wood provides too much energy compared to solar cooking. At sea level 1000 watts per m2 is the norm (here it is more because of the altitude). Our box cooker has .25m2 window and one .25m2 reflector so we estimate a possible energy gain of 300 watts per hr. Those 900 watts is usually plenty of energy to cook for a family of 5 to 8.
Our cookers can average 140 to 150oC empty, but the cooking occurs from 70o to 100o C, above 100o C you are just wasting energy. While it is true that cooking times are longer, in our case the average is 2.5 to 3 hrs cooking time. Just like in learning to use a rocket stove, one must change cooking habits. If the solar cooker is loaded around 8:30 or 9 then by 12:30 they have a well cooked meal but did not have to feed the fuel or stir the pot and end up saving 15 hrs or so a week that often are used productively to provide for the family.
As you look again at the chicken cooking in this solar box cooker, remember there are many health benefits of slow cooking. I have often enjoyed the surprise of folks when they bite into that juicy chicken, not dried out from too much heat and exclaim that it is even cooked all the way through to the bone. Folks used to eating fried chicken here complain about the chicken not cooked next to the bone and use that as a test to see if the solar cookers “really do cook”.
I urge you to reconsider the information you based your opinions on if you are discounting the value of solar cooking.
Once again I join Dean and others in stressing the importance of combining technologies like retained heat, solar and efficient biomass. We are just an email away if you would like more information.
Warm and sunny regards
David Whitfield
www.cedesol.org
info@cedesol.org

COOKING WITH CORN COBS IN SAIPINA, BOLIVIA David Whitfield, CEDESOL, Bolivia, June 2007 Marlow (Corn cob)

Saipina Valley Saipina is located about 1346 meters above sea level, a little more than 1200 meters below Cochabamba. Usually the climate is hot but the day after arriving a southern wind brought cold air in from Antarctica and everyone had to find some warm clothes. The trip from Cochabamba takes between 6 to 8 hours depending on the climate and fog that can be encountered in some parts of the trip. Carlos, the GTZ chauffer really did a great job of getting us there quickly and safely. Right after arriving we went to look for candidates for the series of test we would be performing. In a small town called San Rafael, right out side of Saipina, a city counsel woman guided us to her house and it was emotional to drive down a road and see CEDESOL stove chimneys on all sides! One of the high lights was finding a stove so shinny that it was difficult to believe the stove had been used. It even looked better than when it was delivered! Doña Corina Montaño assured us that she used her stove for every meal and in fact it was so clean and shinny because she just loved her stove so much! Another exciting moment was walking into a kitchen and finding a stove in operation on a beautifully made cane pole and mud base, using corncobs to cook with. I asked Doña Veraranda if she had any problems with her stove. After a lot of urging she said the only thing negative she could think of was that if you put a big pot on it (30 to 50 liters) it took a while to boil. She said it never smokes not even with corn cobs as fuel. She normally cooks for a family of 4. Marlow is the Bolivian word for corncob. When you check out the video notice how the pot is boiling but no smoke is coming out from around the pot even though it is significantly smaller than the hole the pot sits in over the combustion chamber. Doña Veraranda Sapina Corn Cob Stove Test results will be published soon. Una estrategia de la lucha contra la pobreza y protección de medio ambiente You may also be interested in the GTZ Waterboiling Test Video and the CEDESOL Stove Assembly Training Video