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Last edited: 25 October 2024
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The Kakamega Solar Oven Project was initiated by the Lions Club of Helsinki Pohjois-Haaga of Finland in 2017 as a cooperative project for solar cooking in Kakamega, Kenya. They were joined by two Kenyan partner organizations: the Lions Clubs of Kakamega and Greater Nairobi. Funding for the project was provided by all the Nordic Lions Clubs together, and the International Lions Foundation.
Technical solutions for the design of the solar box ovens were based on earlier prototypes developed by the Technology for Life Association (TfL) (Tekniikka elämää palvelemaan ry.) in Finland and in Ethiopia.
First stage 2017-2021[]
Participants of the solar oven training session in Kakamega, 2019, Photo credit: Kakamega Solar Oven Project
The first phase of the project was completed in 2021, with a second phase scheduled to begin in 2023. About 1,500 solar box ovens were constructed in Kakamega township during the first phase and distributed to local households in Kakamega and selected villages in Kakamega County. Before distribution of the ovens, a two-day solar cooking training program was arranged for 40 members of local women’s associations and environmental teams, Also a solar oven user manual was produced to help with training new users.
About ten different local dishes were prepared during the training program, including the traditional Kenyan dish ugali (maize porridge) and cakes. The trainers have been responsible for the distribution of ovens to families and providing training for their use. A follow-up study of the use of the ovens was carried out in July 2022, and the women in the households receiving the solar ovens report being very satisfied with the performance and practicality of the ovens.
Solar oven construction and function[]
The Kakamega solar box oven, Photo credit: Kakamega Solar Oven Project
Image credit: Kakamega Solar Oven Project
The solar ovens constructed in Kakamega during the first stage of the project (2017-21) have a framework of thick (6,5 mm) film-coated plywood, which has been cut into interconnecting pieces, making for easy assembly. Part of the plywood was donated by UPM, a Finnish forest company. The bottom and exterior walls of the oven have 30 mm of hard rockwool thermal insulation, with the inside oven walls made from 0,5 mm aluminum sheets. The bottom panel is painted black. The transparent lid of the oven is 4 mm thick polycarbonate sheet. Also, tempered window glass can be used, but polycarbonate is more durable (does not crack or brake). A silicon rubber band ensures that the transparent lid rests tightly on the oven wall. It is important to prevent heat from escaping from the oven.
The covering lid is made of plywood. Its interior has a reflective (glossy) surface of aluminium foil. The other sides of the oven have removable reflective aluminum sheets (side reflectors). The lid (back reflector) and the side reflectors are adjusted occasionally during cooking, so that the solar radiation is concentrated inside the oven on the black-painted cooking pots.
The temperature inside the oven can reach 150 °C (302 °F) during midday in sunny weather. Effective cooking time in Kenya is from about 9 in the morning until 4 in the afternoon. The efficiency of the oven can be improved if thermal insulation would be made thicker, and the reflectors made from very glossy material. However, in Africa it is necessary to try to minimize the material costs. In Finland, Kari Silfverberg mentions he has built his own solar oven with thicker thermal insulation, and it is able to reach 170 °C (338 °F) degrees during sunny days in summer.
Second stage 2023-24[]
The Helsinki Pohjois-Haaga Lions Club received a private donation in 2021, which provided the opportunity to begin the second stage of the project. There have been some modifications made to the solar oven design during this stage. The framework of the new oven model is galvanized ironsheet, which is a strong material and reasonably cheap in Kenya, since it is a common building material. The outer shell is .8 mm thick and the inner shell .6 mm. The ironsheets are cut in a metal factory in Nairobi using their CAD computer program. This allows the sheets to be assembled almost without screws, which makes construction fast and easy. The thermal insulation of the bottom and side walls of the oven has been increased to 50 mm thick glasswool.
The targeted upper limit for the construction cost is 80 euros per oven. This is affordable for middle income families in Kenya, but too high for low-income families. For them a subsidy will be needed. It has however been estimated, that the cost of the solar oven can be recovered in about half a year due to less expenditure on fuelwood, charcoal, biogas, kerosene or electricity.
Advantages of cooking with solar ovens[]
Various types of solar ovens and solar cookers have been developed and used in the south since the 1970’s. But knowledge of solar cooking technology is still limited in African countries. Therefore it is important to initiate projects and distribute solar cooking knowledge to local communities all over Africa, particularly in areas where fuelwood and charcoal consumption is high and deforestation a growing problem. The main advantages of solar cooking - particularly using solar ovens, are environmental, economic and health related:
- The need for fuelwood and charcoal for cooking is reduced, and thus problems of deforestation and forest depletion can be reduced.
- No need for the time-consuming and laborious collection of fuelwood, which is often the responsibility of young girls
- Economic benefit: There is a significant reduction of spending on fuelwood, charcoal, kerosene, and electricity. Solar radiation is free of charge, and abundant in tropical areas.
- Cooking pots do not wear out as fast as when cooking is done with firewood.
- Health benefit for housewives: Cooking free of air pollution from smoke and soot. Air pollution is then decreased in the neighborhood or village.
- No risk for fire hazard or skin burns or burning up the food.
- Cooking with a solar oven is a safe slow-cooking method, which provides housewives possibilities to perform also other tasks while cooking.
- The solar oven has been quite functional for preparing the traditional Kenyan ugali porridge.
Experiences from the Kakamega solar oven project[]
The users of the solar ovens in Kakamega have expressed their satisfaction of the functionality of their ovens. Particularly important has been their experience, that cooking of ugali porridge has been easier with the solar oven than using the traditional fuelwood cooking method. Experience has also shown, that many dishes (f.ex. eggs, potatoes, carrots and other vegetables) can be prepared with only small amounts of water. Meat dishes are prepared rather slowly, but without risk of burning. Rice cooking is also easy with a solar oven.
The long-term target for the Kakamega solar oven project is to make it possible for local small industries to start producing their own solar ovens for sale, and thus create new employment. This can be possible once the use of solar ovens has become common and their advantages has become well known. The hope is that other environment and development institutions in Africa will increase solar cooking development and training activities. The Finnish NGO WaterFinns is planning to start solar oven development activities in Ethiopia, based on the experiences from the Lions Clubs cooperation in Kakamega.
Reports[]
Contact[]
Lions solar team in Helsinki
Kari Silfverberg
Email: karisilf@gmail.com
Kakamega Lions Club
Project coordinator
Rajinder Pape Sembi
Email: papesembi@gmail.com
Training and follow-up
Margaret Owino
Email: maggyowino@gmail.com