In January, 1989 Bob Metcalf of Solar Cookers International traveled to Sierra Leone to introduce solar box cookers (SBCs) there. The following article contains highlights from his report on the trip:
My plane arrived in Freetown, Sierra Leone before sunrise Sunday morning, January 8, 1989. The US-AID office in Freetown had dispatched Mr. Komrabai to meet me at the airport and guide me through the maze of bureaucracy.
I learned about the rapidly deteriorating economic condition in Sierra Lone. Their currency, the Leone, has been devalued so much in this last decade that it is very difficult for people to buy imported goods. A pediatrician said that malnutrition was common among children in Freetown.
On the ride to Njala we saw several trucks loaded with fuelwood which is brought to Freetown for sale. In rural areas, people stack the small bundles of firewood by the roadside. Buyers pay from 2 to 4 Leones per bundle, depending on the proximity to Freetown. This great demand for wood in the urban area is resulting in deforestation of the surrounding area. Now and then people would be seen along the roadside carrying fuel on their heads.
By 4:30 pm we had assembled our materials at the conference room of the Institute for Agricultural Research (IAR) and met 20 people for our first session. I gave an overview of Solar Box Cookers (SBCs), including my personal use for 11 years, the international projects which have recently been stated, and the significance of this project for all of West Africa. I then covered the basic construction principles of SBCs, and had the group assemble the first SBC kit. Quickly the men and women took over measuring foil pieces, painting thin layers of diluted glue on cardboard, attaching the foil, making the boxes, side insulators, and toppers. They estimated that the price of foil to make this size SBC was 150 Leones, and the glass would cost 400-1200 Leones. By 6:00 pm Sierra Leones's first SBC had been assembled and photos of the group were taken. I told them that they really wouldn't believe it could cook until they saw food coming out of it, which we would do the next day if the weather cooperated. Already there was great anticipation.
On Tuesday, January 10th we started the workshop shortly after 9:00 am. This included Dr. F. Dahniya and now about 30 workshop participants. I reviewed SBC construction principles and then two groups were formed to assemble their own SBC kits. This time they needed only minimal supervision, as participants from the first day did most of the teaching for the new participants. There was something for everyone to do and this hands-on approach was thoroughly enjoyed.
Dr. Dahniya had arranged for food to be cooked in the SBCs and I saw the nutritionists prepare the popular local dishes: fish rubbed with a hot tomato paste, short grain white rice, and groundnut soup (more like a stew, with fish & chicken, peanut butter emulsified in water, a Magi cube, pepper, and the hot tomato sauce). These three pots were placed in the first SBC about 12:30 pm, with all the workshop participants observing. Despite the relative low sun angle and harmattan (dust from the Sahara in the air), oven temperatures without food were well over 95 °C (203 °F), which would be able to cook this food in about three hours.
The home economists told me that they could never actually cook food in the classes they taught, as electric and gas appliances were generally unavailable in schools as well as in the general population. SBCs will open an entirely new dimension to them. Not only can SBCs be used to cook and bake, but the classes can actually build the SBCs they later will use.
I was told that in rural areas, many houses have flat rooftops where foods are dried. SBCs would be ideal there. Women will love to come home from the fields and have their meal already cooked. They will also like not having to walk for miles to collect firewood.
Around 1:00 pm the groups had completed their SBCs and had autographed one topper piece to witness their work in building the SBC. We moved one pot of food from the first SBC to each of the newly made SBCs about 1:15 and faced these cookers to the southwest. We then took a break and returned to our guest house for lunch and to prepare for the afternoon session.
We reconvened at 3:30 pm. The food was probably cooked by this time, but it wouldn't hurt to keep it in the SBCs until we were ready to eat it. By 4:30 pm we were ready to sample the solar cooked food. The crowd had swollen to over 50 people to see the lids being lifted from each SBC and then the lids taken from each pot. Cheers rang out when a nutritionist lifted the lids and steam came out. First the groundnut soup, then the fish, and finally the rice were presented. The nutritionists soon served samples of the food to all participants, whose excitement was great now that they too knew that these solar boxes worked.
Before people left for the day, I invited them to take a Colilert MPN tube home with them to fill to a mark with their family water supply. The Colilert MPN tube contains reagents which water quality indicator bacteria metabolize to give distinct results after incubation. The Colilert MPN system was much simpler and more precise than the tests I had used when sampling local water supplies in Guatemala and Mexico. I also encouraged workshop participants to bring in scrap cardboard which we'd convert to SBCs at our next workshop.
On Wednesday Dr. Jonsyn numbered and logged in the Colilert water samples people brought in during the morning. These came from wells, reservoirs, streams, and even supposedly boiled and filtered supplies -- the sources of water these people used. Our agenda for the workshop was to build SBCs from scrap cardboard using our empty boxes and boxes others brought in. I showed how paper templates for pieces could be used, and how smaller pieces could be taped and glued together to make the appropriate sizes. I had anticipated that the group would make one box, but the group which started on the inner box wanted to make their own outer box and the group which started with the outer box wanted to make their own inner box, so two SBCs were made. Instead of glass for the lid, we used polyester oven cooking bags which were cut open and attached in a cardboard frame. The frame was then attached to the underside of the lid. The main box was completed by about 12:30 pm and the lids were finished at 2:00 pm when we adjourned for two hours after taking photos of each group with its SBC. The reason for experimenting with polyester instead of glass was that glass can be expensive and difficult to obtain in many countries. I wanted to experiment with inexpensive and easily transportable polyester, which my tests in Sacramento had indicated was about 80% as efficient as glass. I'm not sure of polyester's durability or long-term survival in equatorial UV light. An engineer at the workshop said he would experiment with a double layer of polyester and make comparative studies.
The nutritionists had prepared a large amount of fish soup, rice, and a Pillsbury banana bread to bake in the SBCs during the afternoon. The harmattan was less intense this day and oven temperatures were running up to 120 °C (248 °F).
A large crowd was present at 4:00 pm when the SBCs were opened and the foods were examined. Cheers went up for the fish soup, then the rice, and the banana bread. Very few people in Sierra Leone have baking abilities, and the SBC offers them a new dimension. I was told that a local rice bread would do very well in the SBC. Again, the nutritionists distributed samples of the foods and the high quality of the taste was noticed.
Dr. Carpenter then led the ceremony where we distributed certificates of participation to each workshop participant. In just 48 hours, these people had gone from knowing nothing about SBCs to knowing how to build them from scratch and how to use SBCs to effortlessly cook their main dishes. Dr. Barrett told the group that he had been involved in many projects in developing countries, but never had he seen such enthusiasm and ability as here in Njala, Sierra Leone.
Thursday morning, Dr. Jonsyn and I recorded the results of the water tests and shared them with the people who brought in the samples. The yellow color indicated the presence of coliform bacteria, a possible cause for concern and a water which would not pass USA water quality standards. Ninety-five percent of local water samples contained coliforms, and 61% contained E. coli, a genuine cause for concern. Drs. Barrett, Jonsyn and I conducted an experiment to demonstrate the ability of SBCs to pasteurize contaminated water. We sampled local water with both Colilert MNP and Millipore Samplers. This water was then heated in a clear quart glass jar. We started heating at 10:30 am and by 12:30 pm the water had reached 67 °C (152.6 °F). We again sampled the water with Colilert and Millipore Samplers. Both samples now tested negative for E. coli.
The nutritionists again cooked a large quantity of fish soup and rice in the SBCs, which was served to many people later in the afternoon, following a closing ceremony. At this ceremony, Drs. Barrett, Moland and I expressed our thanks for the excellent workshops so many had participated in. Dr. Moland, the highly esteemed leader of the ACRE project said: "I believe we are making history with this project."