We used several years data available on the websites of NGOs and institutions to achieve our projections and our solar cooking projects. For all countries of the Sahel environment ministries are almost all identical findings.
- The wood is 90% the only energy source used by families.
Over the past 10 years:
- The population grew by 35 % to 50% in each country
- wood energy applications are becoming increasingly important
- The desert areas are constantly expanding
- The price of wood has increased by 30% to 50% depending on the region

These figures project us towards an important energy crisis that will occur in all countries of the Sahel.

When conducted with associations Project Sur la Piste and Codegaz we conducted studies and projections on the development of solar cooking. We followed every day more than 100 families in Burkina Faso distributed in eight different areas. These studies have allowed us to make databases on the habits of users of solar cookers for their energy needs and their culinary habits.

Kera Energy took care of all the processing of these databases. More than 50,000 data were processed, analyzed and synthesized.

Some key figures obtained by this study in 2012 - 2013 in Burkina Faso:


In many reports the numbers are very different needs for Kilos of wood per day and per person. We must be very careful on the figures announced. In our study needs can vary from simple to double depending on the assessment of respondents. One explanation could be confusion between the needs kg of wood for cooking and wood needs for all family activities. (Meals, activities, food processing, dyeing, cleaning tools, etc..)
The figures reported in the reports are national averages including preparation of meals but also craft, commercial and industrial activities ... It is common to find wooden figures need more than 1.5 kg per day per person.
Our studies focus exclusively on the needs kg of wood for cooking and mainly operates in rural areas. Our estimates range between 0 75 kg and 0.9 kg of wood per day per person depending on season and region. needs wood energy for cooking would therefore 328kg of wood per person per year for an average of 0.9 kg per day . If this figure by the number of inhabitants of Burkina Faso, 17 million is multiplied, we can deduce that more than 5.5 million tons of wood are burned each year to cook meals.


Even in the heart of West Africa, it is not possible to cook with a solar cooker all day and any what time. A solar cooker is a complementary alternative energy.
Quite simply it is not possible to cook in the evening or at night. It is not possible to cook the days of cloud, rain or harmattan. Our average show that over a year it is possible to use a solar cooker 65% of the time is about 230 days a year.


The number of kg of wood that can be saved per year with a solar cooker is more difficult to treat since it will depend on the actual use of the solar cooker. With the same solar cooker and over the same period, a family of six people using it only for meals will not save the same amount of wood a family of 10 people using the cooker for these meals and activities sale or processing. When talking about saving wood solar cooker must therefore know the context in which the solar cookers were used.
During our study we found that the average number of families using the cooker was 6 people.
Our statements newspapers have allowed us to project an average of 0.75 kg of wood per day and per person saved to prepare meals with a solar cooker and a thermos Cart (Bitam Toré).
For a solar cooker and Bitam Toré used only for meal preparation, we can project the economy of one ton of wood per year per family of 6.
calculation is as follows:
0.75 kg x 6 people * 230 days = 1035 kg of wood
This figure may represent up to 65% less wood per year per person.
In the case of income-generating activity or community group we can achieve much higher percentages up to 80% savings. Some activities such as dyes can be made ​​at any time of the day and concentrated only on sunny days. FCFA SAVED It is important to know the financial savings that can make a solar cooker in a family. This allows to make projections on the flow capacity of solar cookers. By the micro-credit system a solar cooker can be completely self-financed. However it is difficult to project a figure. The criteria are many and important differences. Depending on the geographic area the price of wood is very different. North of the Sahel timber prices can be twice more expensive than in the south. In cities the price of wood is higher than in the countryside. Depending on the season and facilities supply timber prices also vary greatly. All families do not buy wood regularly, some will look directly into the bush whenever possible. All these variations complicate projections saving wood. In our studies we showed an average of 500 FCFA for a 10kg bundle of wood. In some areas the price of wood has doubled over the last 10 years. To determine the achievable cost savings with a solar cooker we project a broad range depending on the situation from 50,000 FCFA to 100,000 FCFA savings per year for a family of 6 people and solar cooker.


With the aim to set up a carbon credit we need to project the CO2 savings that can help make the use of solar cookers. The documents of the National Organization of Forestry and Environment Ministries and energy we can find equivalences Kg wood / carbon / CO2.
Equivalencies are as follows: 1 kg of dry wood produce 1.4 kg of CO2 during its combustion. So for a family of six people in Burkina Faso it is possible to save 1.4 tons of CO2 per year and cooker.
It might also be interesting to calculate the number of CO2 produced by the cutting and transporting 5.5 million tons of wood each year to cities and villages ...


We studied the energy that powers the family had at their disposal with traditional homes. The ownership of an energy alternative is easier if it is not a constraint or a decrease in the current comfort. With some calculations (see "Calculating the power of solar cookers") we determined the wattage of homes used by families. For families of 6 to 10 people families generally have at their disposal the powers of 1000 to 1500 Watts with their wood burning fireplace. To help ownership of solar cooking is relevant to propose solar cookers are as close as possible to these powers.
In case families would have no other alternative, solar cookers same less powerful would be used despite the change of habit that require cooking.
Families use between 2 and 3 am their homes to prepare meals per day which is a need of about 2.5 kWh per day per family of 6 . A solar cooker 1000w for the best periods of sunshine can give up 6kWh day.


There are several ways to calculate the power of a home or a heat source. We can use these formulas for solar cookers. Theoretically there is 1000 watts per square meter of sunshine, but the factors of restitution of this power is much more complex. A solar cooker with an area of 1m2 never restore 1000 Watts. The quality of the film mirrors the accuracy of the concentration, the opening of the parabola are very important factors for the return of power.
Relatively simple tests exist to calculate the power of a solar cooker. The most widely used method with water as follows:

The power P is equal to the heated M x C x specific heat the temperature of the final water mass TF - the initial temperature TI, divided by the duration D seconds.

P = (MXC) x (TF-TI) / D

A solar cooker that is boil 3 liters of water at 20 ° to the origin (specific heat of water is 4180) in an aluminum pot 1.5kg (specific heat of aluminum 850) in 15 minutes ( 900 seconds) will have a capacity of about 1200 watts.

(3 x 4180 + 1.5 x 850) x (100-20) / 900 = 1228

We used this method for testing solar cookers is a reliable and relatively easy to implement in accordance with the same protocol and the same metrics technique.
Other techniques exist, it is possible to measure the amount of evaporated water for a given time in order to calculate the power of a stove. The method seems a bit more complex to make, but it allows to compare the results and performance.
A boiling, the water temperature is constant, the container also. The energy provided by the cooker no longer serves to raise the temperature but to vaporize the water. M1 calling an initial mass of water to the boiling temperature of the mass M2 after a duration t bp, H the enthalpy of vaporization of water (2 260 The power of the cooker can be obtained by: P H = (M1-M2) / t


cookers remain inexpensive to manufacture, however all equipment materials can not be found. locally
reflectors film or aluminum plates that allow the reflection of sunlight are complex to manufacture materials. They are often three-component or four-component that can not be produced using traditional or local.
Some solar cookers use glass tubes with walls and vacuum coated aluminum nitride, it is also difficult to manufacture these parts locally.
To achieve solar concentration, satellite antennas steel very large sizes can be used. In this case the local manufacturing and small amounts will be almost impossible. It will necessarily be importing these parables.
Certain parts often require to be imported from China or Europe to manufacture in Africa.
manufacturing costs are highly uncertain based on the quantities and import product costs but also on the basis of expected solar cookers requirements. We can consider the cost of € 75 150 € to achieve an efficient solar cooker Burkina Faso can be used daily by a family Sahel and this over several years.


We have in our projects involve different products to allow optimization of wood savings. The most interesting formula is a combination of three complementary products. A solar cooker, a Bitam Toré and cooker Wood Peeler (EPC or home improvement). We thus arrive at more than 75% of wood per year per person savings for cooking meals. We estimate a 30% savings possible through the use of an EPC.


Solar cooking when used with cookers with a very specific focal point can be just as dangerous as cooking over a wood fire or gas. The temperature at the focal point can exceed 500 ° and burns or fires can happen. There is no flame or embers with solar cookers, the heat source is invisible to the naked eye if the focus is not focused on a pot.
During the pilot project support 139 families We follow users for almost seven months and carried out important work of raising awareness about the risks he may be with a solar cooker. Through this work we have obtained encouraging results, we reported only one minor accident. A figure of 0.6% of accidents on the project . This result is relatively low while the women cooked almost every day with their solar cooker.
however it was a pilot project with an almost daily user support. Solar cooking with cookers with a very specific focal point must be developed carefully and carried out in the framework of projects supervised by experts and people who know the properly functioning cookers and risks.

Specializing in the development of solar cooking in the Sahel Company:
• Advocacy, communication and training
• Support NGOs and businesses in their development projects sustainable and inclusive
• Feasibility studies, consulting



44 rue Emile Raspail
94110 Arcueil
Tel : 06 42 61 09 77

N°SIRET : 539-319-129 00062


*Les chiffres clés sont tirés des études et des projections de Kera Energy.
Aucune autre entreprise, association ou personne ne peuvent être tenues de responsable pour ces données.