Solar Cookers International Network (Home)



by Petri Konttinen

Thesis submitted in partial satisfaction of the requirements for the degree of Master of Science in Engineering, Espoo, September 25th, 1995


Faculty of Mechanical Engineering
Laboratory of Energy Technology
Laboratory of Industrial Psychology


1. Purpose of the study

1.1 Methods used

2. Brief history of solar cooking and future prospects

2.1 Earliest experiments

2.2 Different types of solar cookers

2.2.1 Box type solar cooker

2.2.2 Parabolic type concentrating solar cooker

2.2.3 Flat plate collector systems

2.3 Brief review of solar cooking projects

2.3.1 India's national solar cooking project

2.3.2 Development and dissemination of solar cookers in China

2.4 Estimate of fuel saving potential of solar cookers

2.5 Conclusion of present situation and future prospects for solar cookers

3. Thermodynamic review of solar box cookers

3.1 Introduction

3.2 Heat gain into a solar box cooker

3.3 Heat loss from solar box cookers

3.3.1 Heat loss from walls and floor

3.3.2 Materials used to prevent heat loss, experiences from Namibia

3.3.3 Heat loss from cover

3.4 Heat transfer from solar box cooker to cooking vessel

3.5 Structural materials used for a solar box cooker

3.5.1 Introduction

3.5.2 Moisture resistance: using a vapour barrier

3.5.3 Practical experiences of materials in Namibia

3.6 Materials and design of the transparent top cover and reflective lid

3.7 Size of cooker and volume of cooking chamber

3.8 Estimate of efficiency of solar box cookers

3.9 Conclusions (and sources of error)

4. Transfer of technology from North to South

4.1 Appropriate technology

4.1.1 The appropriateness of solar cookers in general

4.1.2 The appropriateness of solar cookers in local conditions

4.2 Participatory methods in development co-operation

4.2.1 Action Research

4.2.2 Participatory Action Research and Participatory Rural Appraisal

4.2.2 Connections between the practice and the organisational level of Participatory Action Research

5. Project plan: Solar cookers for use in Namibia

5.1 Purposes of the M. Sc. Thesis

5.2 Background of the project

5.2.1 History

5.2.2 Planning of the field study

5.2.3 Methods used in the field study

5.3 Concrete plan and schedule

5.4 Conclusions

6. Field study of the project in Namibia

6.1 Creating a support and contact network in Namibia

6.1.1 The authorities

6.1.2 Private companies

6.1.3 The University of Namibia

6.2 Evaluating the usability of solar box cookers by interviewing their users in Ovamboland

6.2.1 Solar cookers in use in the Oshakati region Jan. 1, 1995

6.3 Organising solar cooker building courses in Ovamboland

6.3.1 The first course for technical teacher - students from Ongwediva College of Education

6.3.2 The second course for people from different local organisations

6.3.3 The third course for rural women

6.3.4 Conclusion of the solar cooker building courses

6.4 Teaching methods used and transferring of information

6.5 Introduction to the evaluation of teaching and appropriateness of solar cookers

6.6 Participatory evaluation of solar cookers with the rural women, means and results

6.6.1 A daily calendar of a rural woman.

6.6.2 A Venn-diagram

6.6.3 A matrix ranking and scoring

6.6.4 Conclusion of the participatory evaluation

6.7 Present situation and future

6.7.1 Solar cookers in the Oshakati region April 15, 1995.

6.7.2 Prospective actions in the near future

6.8 Conclusions

7. Discussion


1. Map of Namibia and general information about the country

2. 'Something new under the sun' - booklet


Faculty of Mechanical Engineering

Laboratory of Energy Technology

Laboratory of Industrial Psychology


Petri Konttinen

Thesis submitted in partial satisfaction of the requirements for the degree of

Master of Science in Engineering

Espoo, September 25th, 1995

Supervisors: Professor Carl-Johan Fogelholm

Professor Veikko Teikari

Instructor: M. Sc. (Eng.) Anneli Pulkkis



Author of the thesis            Petri Konttinen                                
Title of the thesis             SOLAR COOKERS FOR USE IN NAMIBIA               
Language                        English                                        
Number of pages                 68 & appendices                                
Date                            September, 25th 1995                           
Faculty                         Mechanical Engineering                         
Chairs                          Ene-47 Energy Technology                       
                                Tuo-53 Industrial Psychology                   
Supervisors                     Professor Carl-Johan Fogelholm (Ene-47)        
                                Professor Veikko Teikari (Tuo-53)              
Instructor                      M. Sc. (Eng.) Anneli Pulkkis                   

In this study solar cookers have been examined from a socio-technical point of view concerning their introduction to Namibia. The appropriateness of solar cookers in practise has been tested in Owamboland, Namibia.

The purpose of the study has been to develop the best suitable solar cooker model for local conditions and users. This includes transformation of theoretical, manufacturing and serial production information to Namibian small-to-medium scale serial production. The project has been critically evaluated from the local users' point of view. To reach these goals the history of solar cooking has been examined both in Namibia and the rest of the world. A thermodynamic review of a solar box cooker has been made to find out the most important factors affecting its performance and design. All this information has been combined in a way suitable to the Namibian climatic conditions and combined with the local people's knowledge of their daily life. The method of doing this has been participatory action research.

Nineteen people from local organisations and the countryside have been taught in three courses how to build and use a solar box cooker. The courses were held in the city of Ongwediva, in Owamboland, Namibia. At the moment four local organisations are to begin a small-scale serial production of locally acceptable solar box cookers.


This thesis is a result of a long interest in the field of utilising renewable energy into the needs of people of developing countries. It is the first of a kind for both of my Laboratories; Energy Technology and Industrial Psychology. I would like to express my warm gratitude to my Professors of both Laboratories, Prof. Carl-Johan Fogelholm and Prof. Veikko Teikari, and the Rector of the University, Paavo Uronen for the possibility, facilities and support for this work.

The number of people involved in this thesis is too large to mention here. I want to thank you all together and separately. Some of these persons have given me a very special help. First of all I want to mention my instructor, M. Sc. Anneli Pulkkis, who guided and supported me, and sometimes also strongly criticised (for which I am especially in debt to her) from the very first initiation of the idea to the end of the writing. I could not have had an better instructor for this work. Other persons in Finland I am especially grateful to are Mr. and Mrs., Risto and Helena Kekkonen and Mr. Ari Lampinen for being the backbone of the project. I have had the pleasure to get to know them better while doing this thesis, as well as my colleagues in room Ko234 at the University.

A very special person, Ms. Hilia Imalwa in Namibia was my partner at work during the whole time in Owamboland. I am looking forward to meeting her, Mrs. Shivute and the other women from the 'Green Namibia Community' again at the beginning of October. I hope we will continue our intercultural co-operation as before. I learned a lot about life in Namibia from these people. Mr. Veijo Koskenkangas and the other Finns were a great help and mainstay in orientating me to the work in Owamboland. Dr. John Strijdom and his family in Windhoek gave me the greatest hospitality I have ever met. When the University of Namibia has persons like him and Dr. Tjipangandjara in its service, the future of Namibia seems brighter than ever.

There is still my very personal sunshine, Mai. Thank you for all the loving letters you sent me while I was in Namibia and understanding the pressure while writing the final version of the thesis. Those letters and your pure existence gave me hope and strength to continue my work in Namibia even on those days, when nothing worked out. Now we are both going to work together there.

Last but not least comes Mr. Harvey Benson, whom I remember as the most encouraging English teacher I have ever known (and a jolly old chap!), who also kindly checked the grammar of the thesis.

1. Purpose of the study

The main purposes of this study are:

1. To critically evaluate the solar cooker situation and possibilities in rural Namibia, especially Ovamboland.

2. To develop the best suitable solar cooker for Namibians with local co-operatives, such as local organisations, users and the authorities.

3. Transformation of information (theoretical, manufacturing and serial production) to Namibian small-to-medium scale serial production.

The present solar cooker situation evaluation was done in the field in Namibia, by interviewing the users. This information is related to previous experiences in Namibia. According to information gained, a suitable solar cooker was chosen for future development, which will be carried out in co-operation with local organisations, institutes and individual users. Three solar cooker building courses were organised and held for people from local organisations and the countryside.

The transformation of information is done by taking the local users' experiences and references into account at every stage of the project. The women of the 'Green Namibia Community Project' in Ongwediva, Namibia, form the core of the solar cooker development and use network, which will be extended to other interested organisations.

1.1 Methods used

The way of writing this study is to 'lift' the generally applicable aspects from the everyday life by critical examination. This means that things done by an organisation, for example, are separated from the things done by an individual.

For the sake of illustration, I have included my own interpretations of some events and/or some actions by individuals between the text in this format. Sometimes it has been impossible to choose to which category some borderline cases belong. In those cases I have followed my best judgment.

2. Brief history of solar cooking and future prospects

2.1 Earliest experiments

The history of solar cooking goes far back in time. The first known solar cooker pioneer was a Swiss, Nicholas de Saussure (1740-1799), who built his black, insulated box cooker with several glass cover more than 200 years ago. Even without reflectors he reached a temperature of 88 C (191 F) (Cheremisinoff and Regino 1978, Meinel and Meinel 1976).

In Africa the first user was an Englishman, John Fredrick Herchel, in 1837. The place was the Cape of Good Hope (South Africa). He used a black box made of hardwood with a double glass window (without reflectors). He buried the box in sand for insulation and reached a temperature of 116 C (Cheremisinoff and Regino 1978, Meinel and Meinel 1976).

In Asia the first experiments were also carried out by an Englishman, William Adams, in India (Bombay) 1878. He used glass planar mirrors arranged in the shape of an inverted eight-sided pyramid that focused light through a cylindrical bell jar into the food container (Meinel and Meinel 1976). He proposed that dead Hindus could be cremated by the sun. This proposal fell into disfavour (Cheremisinoff and Regino 1978, Meinel and Meinel 1976).

In America, Samuel Langley (an American), was the first solar cooking pioneer in 1884. He used a box-type cooker on Mount Whitney, California, at an altitude of over 4 km (Cheremisinoff and Regino 1978).

After these early pioneers there have been other equally influential solar cooker disseminators and researchers in this century. To mention some of the many: Dr. Maria Telkes, Dr. Edvin Pejack and Mrs. Barbara Kerr of the USA, Mr. Ulrich Oehler from Switzerland, Mr. Klaus Kuhnke from Germany and Dr. Michael Grupp from France, for example (Solar Cooking International, 1995).

2.2 Different types of solar cookers

Since the days of the earliest pioneers, hundreds of different types of solar cookers have been invented and tested (Grupp, 1991). Still, the laws of thermodynamics determine (and have always determined) those factors that make a solar cooker fit for use (see Chapter 3).

The solar cookers in use usually belong to one of the three main categories:

a) box type solar cookers b) parabolic concentrators c) flat plate collector systems. (For other types of solar cookers see Grupp 1991 and Kuhnke 1990). For practical reasons the field study of this thesis concentrates on the box type solar cookers. The thermodynamical review of a box type solar cooker is described in Chapter 3.

2.2.1 Box type solar cooker

A typical box type solar cooker consists of an insulated box with a transparent cover made of glass or plastic (Fig. 2.1). Usually the box also includes one or more adjustable external flat reflectors ("boosters") in order to enhance solar radiation into the cooker (Grupp 1991). The operation of a solar box cooker is based on the greenhouse effect. The maximum temperature is about 150 C.

Fig. 2.1. A classical solar box cooker used in Karachi (Kuhnke et al. 1990).

Classical box cookers are more practical in use than concentrating cookers, since they do not need tracking. On the other hand, their thermal performances are often quite poor, mainly due to a bad heat transfer into the pot. Also, basic quality requirements were often not met in the past, resulting in short lifetimes (Grupp, 1991).

2.2.2 Parabolic type concentrating solar cooker

A parabolic concentrator solar cooker has a collector, which consists of either a reflecting or transmitting concentrator concentrating the solar irradiation onto a focal point (Fig. 2.2). The cooking pot is placed at the focal point. The advantage of this type of concentrator system is that they can reach high useful temperatures: on the other hand, the need for frequent tracking forces the user to work in the sunshine under particularly strenuous conditions of heat and glare.

Fig. 2.2. A collapsable transportable aluminium reflector cooker

(Kuhnke et al. 1990)

Parabolic concentrators have good thermal efficiency and reach high temperatures, but require frequent "tracking" (that is, changing the position of the device according to the sun's position). Also, these cookers have a tendency to get knocked over by a strong wind and suffer from dirt deposits on the reflective material (Grupp, 1991).

2.2.3 Flat plate collector systems

A solar cooker is called a flat plate collector system if its collector part and its cooking vessel(s) are physically separated, either in different cases or in different compartments of the same casing, and if its collector system is of a flat plate type, with or without booster mirrors (see Fig. 2.3.).

Fig. 2.3. A flat plate collector (Kuhnke et al. 1990)

The advantages of a flat plate (as in Fig. 2.3.) collector are: they do not need tracking, they allow for unattended cooking and for cooking in the shade, if the kitchen part is situated in a building or under a roof. Also, there is no upper limit to size, contrary to box systems: even very big, institution size cookers can be designed.

Their drawbacks are that a supplementary heat transfer (between collector and kitchen part) has to be organised. So far, such systems have been more expensive, heavy and bulky than box systems of the same capacity (Grupp, 1991).

2.3 Brief review of solar cooking projects

The dissemination of solar cooking information has been carried out for more than twenty years now. The success has been less than satisfactory compared to the efforts made (Kuhnke et at., 1990) Why is this? Grupp (Grupp, 1991) gives some reasons. Technical problems have often occurred; the cookers have not been practical, or they might have demanded too much attention from the cooks, or they have not been versatile enough (unable to cook all of the traditional dishes). The earliest models have suffered from being ahead of the times: people have had enough low-cost or free fuel (usually firewood) to use. Socio-economic and cultural problems have also played a major role in these failures (Grupp, 1991, Pejack, 1990, Kuhnke et al., 1990, Alward, 1982, to name a few)

According to Solar Cookers International, solar cooking has been (or is currently being) introduced into 69 countries world-wide (Solar Cookers International, 1995). The largest number of cookers are in India and China: approximately 340 000 in India and 140 000 in China, at the end of 1993 (Nandwani et al., 1994). In both countries the solar cooking programs have been promoted by the government.

Countries like Pakistan, Kenya, South-Africa, the USA and Switzerland are far behind these numbers; there are less than 20 000 solar cookers in each of them. (Solar Cookers International, 1994, Pejack, 1992, Nandwani et al., 1994). The number of cookers in other countries can be counted in the hundreds or thousands. The sources for these numbers are in contradiction with each other concerning some of the statistics. Therefore it is impossible to give any up-to-date numbers. In addition, the number of existing solar cookers in some country does not mean that all of them are in active use.

I will have a short review of the two most visible solar cooking countries, India and China, which have had the solar cooking projects promoted by the government (For other countries, see the above mentioned sources and Strebel, 1992, Blankenship, 1990, Group ULOG, 1993, Blum, 1993?, Rodgers, 1992).

2.3.1 India's national solar cooking project

The solar cooking dissemination project has been a part of India's National Program for the development and use of renewable energy sources since 1982. Eighty five percent of the (mainly) box - type cookers have been distributed in six states: Madhya Pradesh, Maharashtra, Rajasthan, Uttar Pradesh, Gujarat and Delhi. The government has offered a subsidy of 33 % of the price of the cooker for potential buyers, the maximum being 150 Indian Rs. per cooker.

Some of the advertisements for solar cookers in India have emphasised their being like any other luxury article (radio, television or refrigerator). In this way the potential buyers are led to get a good image of solar cookers. This approach together with subsidies has sold the largest number of solar cookers in the world. Nevertheless, compared to the about 800 million inhabitants of India, the number, 340 000 cookers sold, can not yet be said to be a massive dissemination (Kuhnke et al., 1990, Garg, 1994).

2.3.2 Development and dissemination of solar cookers in China

The first solar cooker in China appeared almost 40 years ago, in 1956. Before 1975, when the first China National Solar Energy Congress was held, only a few people researched solar cooking. In 1983, at the Conference of National Comparison and Exchange of Solar Cookers, 48 institutions presented more than 100 models of solar cookers, of which 80 had been tested. By the end of 1983, about 50 000 solar cookers were in use in China.

About 100 000 of the solar cookers in use in China now are of the eccentric axis concentrator type. About 90 % of this type of cooker are in use in Tibet and nortwest China. The number of other types of cookers is unknown, but estimated to be much larger. The eccentric parabolic reflector was first made from conventional cement (160 kg), then from a thin layer of fiberglass reinforced cement (60 kg).

China today has a strong development and research of solar cookers. The need for primary energy is huge in China, which has almost a 1 billion rural population. The potential for solar cooking both economically (saving fuel), and in satisfying rural people's primary energy needs is vast (Liu, 1994 and Wang, 1992).

2.4 Estimate of fuel saving potential of solar cookers

UNICEF Evaluation Office had an estimate of the fuel saving potential of solar cookers (not only the box-type) made by SYNOPSIS in 1994 (Synopsis, 1994). The results are shown in Table 3.3.

Wood Consumption                                                               
Global Fuelwood Consumption in Million Tons per Year                  1200     
Estimated Percentage for Cooking                                      80 %     
Global Fuelwood Consumption for Cooking in Million Tons per Year      960      
Per Capita Ann. Fuelwood Consumption for Cooking, Tons                0.48     
Per Capita Daily Fuelwood Consumption for Cooking, kg                 1.32     
Typical "Expensive" Wood Market Price (US$/t)                         80.00    
Typical "Normal" Wood Market Price (US$/t)                            30.00    
Estimated Wood Savings by Solar Cookers                                        
Estimated Average Duration of Non-use, e.g. Rainy Season (Months)     4        
Estimated Economy During Use Period                                   90 %     
Average Year-round Fuel Savings                                       60 %     
Annual Wood Saving Potential by all Models of Solar Cookers in        346      
Million Tons                                                                   
Cost Per Ton of Wood Saved, Base Model (US$/t)                        2.89     
Pay-Back Time (Months), Base Model, "Expens." Wood                    4        
Pay-Back Time (Months), Base Model, "Normal" Wood                     12       
Market Estimated for Woodsaving (e.g. Solar) Cookers                           
Total Users of Wood for Cooking Worldwide (Millions)                  2 000    
Total Potential User Families (Millions)                              333      
Market Estimated for Base Model Cookers                                        
Estimated Market Penetration Base Model                               50 %     
Estimated Market Price Base Model in US$                              50       
Total Market Base Model (Million Units)                               167      
Total Market Base Model (Million US$)                                 8 333    
Estimated Functional Life (Years)                                     10       
Replacement Market Base Model (Million Units per Year)                17       
Replacement Market Base Model (Million US$ per Year)                  833      
Market Estimate for Elaborate Model Cookers                                    
Estimated Market Penetration Elaborate Model                          10 %     
Estimated Market Price Elaborate Model in US$                         300      
Total Market Elaborate Model (Million Units)                          33       
Total Market Elaborate Model (Million US$)                            10 000   
Estimated Functional Life (Years)                                     10       
Replacement Market Elaborate Model (Million Units per Year)           3        
Replacement Market Elaborate Model (Million US$ per Year)             1 000    
Total Market All Models (Million Units)                               
Total Market All Models (Million US$)                                 
18 333   
Replacement Market All Models (Million Units per Year)                20       
Replacement Market All Models (Million US$ per Year)                  1 833    

Table 2.1. Estimated fuel saving potential of solar cookers (Synopsis, 1994).

This world-wide estimate concludes that the annual wood saving potential is 346 million tons (346 000 000 000 kg) of wood, and the total market of solar cookers is more than 18 billion US$ (18 000 000 000 US$). These numbers may be criticised. Especially the Estimated Market Penetration of the Base Model of 50 % seems very high. Still, if even a small fraction of this will come true, the effect will be tremendous.

2.5 Conclusion of present situation and future prospects for solar cookers

According to latest available information there were more than half a million solar cookers in use in the world at the end of 1993 (Nandwani et al., 1994, Solar Cookers International, 1994). Three hundred forty thousand of these were in India and 140 000 in China alone. This is still not a lot, when it is compared to the estimated total market of 200 000 000 units (it makes 0.25 % penetration, roughly).

There remain many obstacles and hindrances in the way. Solar cookers are not like microwave ovens, which spread like wildfire in industrial countries because of their easy, fast and convenient use and adjustability. Solar cookers have to be made similarly attractive. They have to be efficient enough, robust, convenient to use and sufficiently cheap for rural people in developing countries. This formula is difficult to solve, but not impossible if enough people will carry out their work on the subject. Reaching the critical mass always takes a lot of time at the beginning, but after it has been reached the exponential growth will come. The future will show, if solar cookers will ever reach that point. The signs are good (see Nandwani et al., 1994, for the latest world-wide information).

4. Transfer of technology from North to South

4.1 Appropriate technology

A definition of appropriate technology says: 'Appropriate technology is now recognised as the generic term for a wide range of technologies characterised by any one or several of the following features: low investment cost per work-place, low capital investment per unit of output, organisational simplicity, high adaptability to a particular social or cultural environment, sparing use of natural resources, low cost of final product or high potential for employment' (Carr 1985). This is surely not the only definition, and maybe not the best one, but due to its comprehensiveness I took it here as an example.

The basic question concerning the transfer of technology is: Which technology is appropriate? And, appropriate for whom? There is no simple answer to this. Always someone gains and someone loses. In the worst case the only winners are the well-paid employees of the development organisations and the local elite. A good (transferred or not) technology helps and empowers the local people to enhance their quality of life. This concerns especially the poorest of the poor, who usually have little or no chance to affect their own lives.

4.1.1 The appropriateness of solar cookers in general

Let us look at the appropriateness of solar cookers from different points of views. Then, in which ways do the solar cookers fit the above definition of an appropriate technology? Previous experiences from Namibia (Ekroos and Nurminen 1993) show that the solar box cookers fulfil the needs of low investment cost per work-place, organisational simplicity, sparing use of natural resources and high potential for employment. The tools needed are very cheap and simple, construction needs just work (no machines) and the cookers can be built mainly out of waste material.

The more complicated questions are those of low capital investment per unit of output, low cost of final product and high adaptability to a particular social or cultural environment. To start any kind of industrial manufacturing of solar cookers, the manufacturer needs some money for the initial purchases. These include glue, paint, aluminium foil, galvanised metal sheet, etc. It depends on the concerned person's income, if he or she can afford these. For example, if the materials for one cooker cost 35 US$ when purchased in a ten cooker kit, then the materials for only one cooker might cost 70 US$. The reason is that there might not be a small enough amount of an item (e. g. paint) for sale, or it is much more expensive.

The low cost of the final solar box cooker is a relative matter. In most developing countries, some people's salaries are about the same as averages in Europe. For them 35 US$ is peanuts. At the same time a vast majority of the people live practically at a subsistence level. These people can not afford any price. This makes it of prime importance to develop the solar cooker so, that those who need it, can afford it themselves. So far I have not seen such a cooker, which is extremely low-lost, as well as effective and robust. In developing solar cookers one always has to make compromises between quality and price.

4.1.2 The appropriateness of solar cookers in local conditions

To make the solar cooker appropriate (anywhere), one needs to take into account the local user's conditions. First of all there is climate, including solar radiation and precipitation. These alone determine a lot: which type of solar cookers can be utilised, and which materials are good enough? For example in Namibia cardboard is a reasonable building material due to low precipitation in the country.

Even more important are the users and possible customers' opinions, needs and expectations. Do they want the most effective model, or do they have enough time to wait for their food to cook? In the first case a paraboloid (concentrating) solar cooker proves satisfactory for most people, but there are costs (in materials and work needed to build such a cooker). If the customer can wait for the cooking coming to an end in peace, then the choice becomes easier. She (or he) can choose among a variety of box-type cookers, depending on which size, materials and quality she/he prefers. But, quality also costs here. It is possible to construct a cardboard solar box cooker which will last for 10 years. It just takes expertise and great care.

A big question is, does solar cooking suite the local culture? Maybe the use of fire in cooking is a taboo? Or, if people are so accustomed to the taste of the burned food, maybe they do not even want to hear about any other cooking method. The Namibians, for example, commented frequently that the taste of solar cooked meat was tender, delicious and easy to chew and swallow. On the other hand they did not care so much about the taste of the millet-porridge (Ekroos and Nurminen 1993). People's diet determines to great extent, if they enjoy solar cooked food or not.

All of the questions concerning solar cookers are impossible to answer, or even to know. The best would be to pin-point the most important questions, and to operate according to the answers given. Likewise, the number of different types of solar box cookers alone is huge. How can one choose or design the best model for a certain place and people? The environment and eating habits give some clues, but it is good to just begin with some models of solar cookers, that both sides consider as a proper. Later on one can adjust the model of the cooker more to local conditions or change it completely if necessary.

4.2 Participatory methods in development co-operation

The history of using participatory methods in development co-operation is long. The systematic use and analytical theories of participating, however, have been developing mainly from the 1980s, and it is still continuing (Chambers 1994). The reason for this change from the previous practice arises mainly from the need to empower the local people's knowledge into the projects. Talking a larger view, the last decades have shown that misunderstandings, failures and completely disastrous projects have constituted a big part of the world's development co-operation (see Smillie 1991 or Cernea 1985, for example).

4.2.1 Action Research

Action research does not have any generally accepted definition. However, some general elements can be found in most of the definitions. For one thing, action research has two objectives: to develop work practices and to contribute to scientific theories. Secondly, action research is usually defined as having the following four special features: 1) real problems of work life as a starting point 2) wide participation of organisation members in the development process 3) a cyclic process including identification of problems, interventions, reflection on the experiences and evaluation of the process and 4) a special, co-operative and equal relationship between the researcher and the researched (Kauppinen and Lahtonen 1994)

The methods of action research are widely used in all kinds of socio-technical and socio-economic research in industrialised countries. However, fulfilling these features still does not satisfy the need for getting the participation of the local people and using their knowledge. The kind of problems development planners, development agencies and development workers deal with are inherently different from the problems that other scientists and engineers deal with. These types of problems are "wicked" compared to the "tame" problems which can be handled by rational and instrumental planning models (Lindøe 1993). The word "wicked" means in this concept that things are entangled in each other: Planning of the expanded mega-cities, global environmental issues and poverty are examples of problems that seem incongruous to rational planning instruments.

People concerned with development co-operation in both industrialised countries and developing countries, have been looking for a more satisfactory method. The local people's position in decision making and the whole process was not satisfactory. Slowly, this led to the development of the participatory action research methods.

4.2.2 Participatory Action Research and Participatory Rural Appraisal

Participatory Action Research (or PAR) is a common name, an umbrella, for several different participatory methods. These include Participatory Rural Appraisal (PRA, Chambers 1994), Rapid Rural Appraisal (RRA), Participatory Assessment, Monitoring and Evaluation (PAME, Case 1995), etc. From these especially the PRA has disseminated like an explosion during the last five years. It has developed from the need to 'move away from extractive survey questionnaires and toward new approaches and methods for participatory appraisal and analysis in which more of the activities previously appropriated by outsiders are instead carried out by local rural or urban people themselves' (Chambers 1994c). This means that the local people will analyse their own situation themselves, together with the outside development co-operative worker. What does this mean, then? Dr. Chambers divides PRA into three equally important pillars (Fig. 4.1., Chambers 1992).

Fig. 4.1 The three pillars of PRA (Chambers 1992).

From the viewpoint of the outsider the three pillars of behaviour and attitude, methods and sharing form the base of PRA. Our (donors, co-operative workers, etc.) behaviour and attitude are the determinant factors in the whole development process: we have to consider local people as equal, not only at the operation level, but also in analysis and proposals. The methods used are numerous and the ones that are most applicable vary from case to case (see Chapter 6.5 for the ones used in this study). Whichever method is used, the results must be shared immediately with the locals, not taken away and statistically analysed somewhere else.

In this study I used some PRA methods (see Chapter 6.6). I could have used more of them, but the primary importance was attached to teaching how to build and use the solar cookers. Still, I tried to follow the attitude of PRA throughout the whole project. Especially I passed the responsibility of evaluation of the solar cookers' appropriateness to the locals.

Dr. Chambers asks, quite justifiably: Whose knowledge counts? Is it the 'donors' knowledge or is it the 'recipients' knowledge? He demands shifts in our professional views (Fig. 4.2).

Fig. 4.2. Shifts in our professional views by Dr. Chambers. (Source: Chambers' lecture, Helsinki, December 1994)

Dr. Chambers points out in Fig. 4.2. that the most acceptable knowledge has been our (that is, foreign "experts," governments, etc.) knowledge. He demands that the concept of development of the professional view needs to be changed from our knowledge counting to mutual knowledge counting. He also demands that the local people are accepted (they O.K.) as decision makers when the decisions concern their situation.

Traditional development co-operation methods (see table 4.1) have not proved sufficient in enhancing the rural people's possibilities to contribute to the development programs. The "specialists" get their views taken into account, as do the influential locals. But what about the poor and illiterate locals? Most of the PRA methods are planned to be visual, so that illiterate people can also participate. Still, it is our attitude that needs correction.

To illustrate the need of change in development Dr. Chambers compared two methods (Source: Chambers' lecture in Helsinki, Finland, December 1994), the one centralised and non-participatory, the other localised and participatory (table 4.1).

                          Method 1                   Method 2                   
(non-participatory)        (participatory)            
Point of departure        Things                     People                     
and reference                                                                   
Mode                      Blueprint                  Process                    
Keyword                   Planning                   Participation              
Goals                     Preset, closed             Evolving, open             
Decision-making           Centralised                Decentralised              
Analytical assumptions    Reductionist               Systems, Holistic          
Methods, rules            Standardised               Diverse                    
                          Universal                  Local                      
Technology                Fixed package              Varied basket              
                          (table d'hôte)             (à la carte)               
Professionals'            "Motivating"               Enabling                   
interactions with                                                               
Clients seen as           Beneficiaries              Actors                     
Force flow                Supply - Push              Demand - Pull              
Outputs                   Uniform                    Diverse                    
Planning and Action       Top-Down (targets)         Bottom-Up (demands)        

Table 4.1. Two methods of development (Source: Chambers' lecture, Helsinki, December 1994)

By this comparison Chambers points out that these methods represent two realities: the old, non-participatory and the new, still developing participatory. The course of change is from the fixed, universally applicable to diverse and local. How then can a researcher derive conclusions from any possible participatory development project so, that the conclusions could be generalised to a similar project elsewhere? Here comes the question about applying the idea and methods of participation at the organisational level.

4.2.2 Connections between the practice and the organisational level of Participatory Action Research

Lindøe (1993) changes the focus of participatory action research from the individual to the organisational level. He uses a double loop learning cycle as a basis (see Fig. 4.3).

Fig. 4.3. The double loop learning cycle (Lindøe 1993)

The learning cycle consists of four stages or phases:

Phase 1: Searching internal and external information

Phase 2: Comparing information with existing values, e.g. norms and standards

Phase 2a: Questioning the norms and standards in the real context

Phase 3: Implementing the plan with the revised values

In this process the "instrumental" part (the single loop) is connected to the "value" part (the double loop) as shown in Fig. 4.4. The single loop represents a standard procedure in any project. What makes this interesting, is the double loop; questioning the norms and standards in the real context. This gives the original information it's real value in real life. Connecting these two makes it possible to "pull back", to draw generally applicable conclusions from a project implemented according to the principles of the participatory method. This is the idea of writing this study also.

The operational part of this project was planned according to this double loop learning cycle. First I collected all available information about solar cookers, Namibian climate and present situation. Then I interviewed the Finnish people with experience of solar cookers in Namibia and sent a proposal plan to the Namibian counterparts. We revised the plan together, both before my departure to Namibia and after arriving there (before implementation). I interviewed local people and got information concerning local cooking habits and facilities. Together with local people from different organisations we estimated the possibilities of solar cooking to contribute in different ways and levels. Then, according to the results of my interviews and observations of the solar cooker users there, we made and implemented the final operational plan.

The people's own, local technologies provide a base upon which new innovations can be implemented (for examples see Gamser 1990). The new technology must be questioned in the real context (Phase 2a in Fig. 4.3) to find out its real possibilities and threats. The local people might not have the knowledge of those new innovations, but they will know if they will work (after pilot implementation and trying, of course).

PRA enhances the stage of pre-assessment of a possible introduction of a new method or technology: PRA methods can be used to empower those people, who are normally not heard in decision making, (women, older people, children) to contribute to the discussion and analysis. This has worked fine in many cases (see Chambers 1994, RRA Notes 1991, 1994, Devavaram 1994, for examples). But, these results are local and not necessarily applicable worldwide (or even countrywide), just as the participatory method (table 4.1) claims. Therefore there is still need to 'use your best judgement at all times ' (Chambers; his lecture in Helsinki, December 1994).

5. Project plan: Solar cookers for use in Namibia

This M. Sc. Thesis has been carried out in a Namibian solar cooker project conducted by a Finnish non-governmental organisation (NGO), Technology for Life (TFL). The project began in 1992, when the first solar box cooker was built in Finland by TFL and donated to the women of the 'Green Namibia Community Project' in Ongwediva (Ovamboland), Namibia. The cooker's design is practically similar to the one presented in Appendix two.

Since 1992 about 50 cookers have been built in (or sent to) Ongwediva. At the moment there are four local organisations in Ongwediva who are interested in beginning small scale local manufacturing of solar box cookers (see Chapter 6.7).

5.1 Purposes of the M. Sc. Thesis

The main purposes for the Thesis are:

1. To critically evaluate the solar cooker situation and future possibilities in Namibia.

2. To develop the best suitable solar cooker for Namibian conditions with local organisations, users and the authorities.

3. Transformation of information (theoretical, manufacturing and serial production) to Namibian small-to-medium scale serial production.

The development method used in the field study was Participatory Rural Appraisal, or PRA, as described in Chapter four. The idea was to generate a developing learning process controlled by the participants. The learning demands that technical, practical and social aspects of the solar cookers be taken into account.

The experiences of earlier users were utilised for the development process. Those experiences (and previous experiences elsewhere, see Kuhnke 1990 for example) indicate that the best suitable cooker has to be reliable, durable, cost-effective and to be adaptable to local people's lives, customs and eating habits.

5.2 Background of the project

5.2.1 History

The history of the solar cooker project has been a result of co-operation with one Namibian NGO and two Finnish NGOs. Together these organisations, the Green Namibia Community Project in Namibia, and the Espoo-Namibia Committee and Technology for Life in Finland formed a base for the future solar cooker dissemination in northern Namibia.

The 'Green Namibia Community Project'(referred to later as the Green Namibia) was originally a tree nursery in Namibia's Ovamboland. It was founded in 1984 by the Espoo-Namibia Committee. The Green Namibia is a so called NGO - development co-operation - program, which is a citizen's organisation in Espoo, Finland. The purpose of the project is to prevent desertification in northern Namibia by founding nurseries, planting trees and organising environmental counselling.

The Espoo-Namibia Committee has rented a one hectare site from Ongwediva for 25 years and established stable tree and vegetable nurseries there. Local women in Oshakati then founded a co-operative society. They took charge of the nurseries with the help of the Espoo-Namibia Committee. Later on they organised courses concerning building different types of stoves, such as advanced mud stoves and Kenyan Jiko stoves. They sold and delivered more than 20 000 plants to the local residents in 1993, at a reasonable price, too.

Technology for Life (TFL) is a Finnish non-governmental organisation of engineers and scientists concerned with the responsible use and development of technology (see Appendix four, page 3). Some active members in TFL (especially Mr. and Mrs. Kekkonen, who were also members of the Espoo-Namibia - Committee) got the idea of solar box cookers from Solar Cookers International (SCI, previously Solar Box Cookers International, SBCI). They modified one of SCI's models to suit Namibian conditions better. They visited the Green Namibia and left the cooker there for test use. Some women liked the idea and wanted to learn to build these cookers. Due to lack of resources, building courses could not be organised then.

The next activities concerning solar cookers were put into effect in 1993, when two Finnish home economist students, Ms. Regina Ekroos and Ms. Tarja Nurminen, wrote their final paper about the solar box cooker project (Ekroos and Nurminen 1993). They organised demonstrations and explained to people how the solar box cooker worked. Local people in Ongwediva showed a lot of interest to the solar box cookers and some of them wanted to buy the cookers straight away. Unfortunately, Ekroos and Nurminen did not have enough cookers to sell.

Ekroos and Nurminen cooked several different foods and compared different types of pots. Their information about the local conditions and foods was used for the continuing development process towards the most suitable solar box cooker models. The solar box cooker seemed very appropriate to Namibia's excellent sunshine conditions. At the same time, the amount of firewood is decreasing rapidly and people need alternative cooking methods.

It was as late as mid-1994, (two years after the first solar box cooker) when the first local solar box cooker building course was held in Ongwediva. At that time Ekroos and Nurminen returned to Ongwediva to continue the project. They taught some women from the Green Namibia how to build the solar box cookers. Organising the building course was not the easiest thing to do; finding suitable materials (especially glass and cardboard)! took a long time, not to mention difficulties to teach people without any technical background how to measure and cut materials for the cooker.

Ms. Hilia Imalwa, one of the members of the co-operative of the Green Namibia, proved to be very enthusiastic and capable of taking care of the solar cooker project. Hence she was later hired as a solar cooker advisor besides her own tree selling job at the co-operative. After the course the women at the co-operative built and sold several cookers themselves without any external help.

Later other Finnish students from the University of Oulu contributed to the project by visiting several schools in Ovamboland and demonstrating the use of solar box cookers. This way the local people became more interested in the idea and knowledge of the cookers spread.

5.2.2 Planning of the field study

The field study was planned between September 1994 and February 1995. The practical part was carried out between the second half of February 1995 and the beginning of May 1995.

The first tasks were to contact the key organisations both in Finland and Namibia and to collect all available information of the project. This refers to Phase 1 of the double loop learning cycle: Searching internal and external information (Fig. 4.3).

I contacted the Ministry of Mines and Energy of Namibia and got legal permission for the project from the Permanent Secretary; Dr. Leake Hangala.

The most important contact organisations in Finland were the Helsinki and Jyväskylä branches of TFL. I also contacted many students and individuals, who had been in Namibia and/or had experience of the Green Namibia Community Project. To my surprise, it was very hard to find any written material about solar cookers from Finland, except articles published in science magazines, such as Solar Energy and SunWorld. With the contacts to TFL I obtained some books (see Bibliography) from different sources. I compared solar cooker programs of several NGOs in different countries during the last 20 years. I tried to figure out, what those factors are that make a solar cooker project a success, or a failure, and why. Later on in Namibia I used this information as a guide-line (together with local conditions, of course).

The following procedure was according to Phase 2 of the double loop learning cycle: Comparing information with existing values, e.g. norms and standards (Fig. 4.3). I wanted to know, how such a project as ours could be carried through in reality. By this I mean, what kind of schedule, for example, is realistic in planning and implementation, or, how many hours per day people are prepared to work in a course in Namibia.

I did not have any previous experience of working in developing countries, but I had done some development studies at the Institute of Development Studies in Helsinki. I was prepared for a long planning time before anything would happen in practise, but even so it took almost one year after the first agreement with TFL before I actually set my foot on the ground of Namibia. There were several reasons for this, but by far the most important reason was money: FINNIDA supports TFL (as a NGO like any other in this field) from the budget of government funds. FINNIDA could not promise (not to mention, grant) any money before the budget was completed. This caused several months delay for the departure and a lot of difficulties in planning the schedule. The other main reason for delays was poorly operating communication channels between Finland and Namibia. Letters took weeks or months before the answer came and telephones and faxes were out of order for long times in Namibia because of flooding.

5.2.3 Methods used in the field study

For this kind of solar cooker evaluation and development project it is vital to plan together with the local participants. It has to be done from the very beginning to guarantee their commitment and targets, which are not always the same as the outsiders' targets. To plan the project fruitfully for both sides takes a lot of open communication between the partners and exchange of views.

The methods used in the field study of the project were:

1. To create a network for supporting the project. This network includes local institutes, such as the University of Namibia, the authorities and companies and organisations involved with solar cookers.

2. Evaluation of the solar cooker situation in the Oshakati area. This includes interviews and close follow-up of the people using solar cookers.

3. Organising solar box cooker building and using courses in Ongwediva. The contents of the courses are based on the process of adult learning by Engeström (Engeström, 1992). The phases of the process include learning and understanding of the technical and theoretical background of a solar box cooker, obtaining personal experience of practical teaching and learning, and evaluation and feedback.

Participants are taught to build a solar box cooker according to the basic rules (Appendix four, pages 16-17). The idea behind teaching is to give the participants an applicable idea of what a solar box cooker is, and how it can be constructed using available materials.

4. Using and evaluating the completed solar cookers. The main idea behind this is to evaluate their appropriateness according to the knowledge of the teaching courses. Participatory assessment methods are used for evaluating the possibilities for future use and dissemination of solar cookers (See Chapter four for participatory research and Chapter 6.6 for actual methods)

5.3 Concrete plan and schedule

The concrete plan of the project consists of four stages, which refers to the double loop learning cycle (Fig. 4.3). The stages are:

1) Searching literature, experiences and applications of solar cookers (Phase 1: Searching internal and external information)

2) Making an initial plan together with Namibian participants and organisations in Finland and refining it in Namibia (Phase 2: Comparing information with existing values, e.g. norms and standards)

2a) Interviewing the solar cooker users in Namibia and introducing some new cookers. Organising solar cooker building and using courses to determine the possibilities to begin to manufacture them by means of small scale industry (Phase 2a: Questioning the norms and standards in the real context)

The solar cooker project will be closely co-operating with the Green Namibia. Their Co-ordinator Hilia Imalwa has been demonstrating cookers successfully, so she is the most suitable contact person between the researcher and the locals. At Walombola Technical Training Centre in Ongwediva they have already manufactured some cookers, and they have a workshop suitable for beginning production. These two will be the core of the developing net, which will also include other schools, organisations, etc. The cookers can be introduced by touring villages and telling people about them, making demonstrations and selling cookers either as do-it-yourself-kits or assembled models. Also it is essential to teach people how to use the cookers.

At the beginning we will find out the availability, usefulness and cost of local materials. Later we will organise solar cooker building and using courses for the local people.

3) Writing the research report and refining the following plan according to the results of the first three phases. (Phase 3: Implementing the plan with the revised values)

(It can also be seen in this way: Phase 3 was already implemented during the building courses, and this is the second double learning loop going on)

The last stage (stage 3) of the concrete plan will be implemented after completing this study. The reason for this is purely due to the delayed schedule. The results of that part will be connected to the revised edition of this study during 1996. The final schedule of the project is shown in Table 5.1.

1.9. 1994        The beginning of the research. Collecting literature about    
                 solar cookers, previous experiences and applications.         
                 Planning of the field stage.                                  
14.2 - 2.5       Field study in Namibia. Defining the plan with local          
                 authorities and organisations. Collecting information by      
                 interviewing the users of solar cookers. Introducing          
                 different solar cookers to determine their usability.         
                 Planning and organising three teaching courses for            
                 development and use.                                          
3.5 - 24.9.1995  Processing and writing the research report. Making decisions  
                 for the future of the project together with Namibian          
                 co-operators. At the same time Namibian co-operators          
                 continue their part of the project, including small scale     
                 manufacturing of the cookers in four organisations.           
25.9.1995 -      Second field work stage in Namibia. Concentrating on          
25.1 1996        enhancing the small scale industrial manufacturing.           

Table 5.1. The final schedule of the project

5.4 Conclusions

The purposes for the solar cooker project are to develop a suitable and very acceptable solar cooker for the Namibian conditions. The co-partners include the authorities, local organisations and final users. To reach these goals three solar cooker building courses for local people and organisations are planned and organised. The aim of the courses is to integrate their knowledge of the local situation and habits to my theoretical knowledge of the solar cookers. The plan includes interviews of the solar cooker users before the courses in order to identify possible problems and their solutions. After the courses those organisations and groups or individuals, who are the most capable and interested, are helped to begin small- scale manufacturing of solar cookers.

7. Discussion

This thesis has been done for two totally different laboratories, Energy Technology, and Industrial Psychology. As a first of a kind for both of them, I had to make my own balance between them. At the moment, when I am finishing the thesis, I feel that there are many things left out both from the technical and socio-technical point of view. Pure engineers might say that there is some absolutely essential information missing concerning the technology aspect. At the same time, technology-transfer people might blame me for making generalisations and simplifications. This situation is very difficult to avoid in a cross-scientific study. From my own choice (and with my professors' approval) it turned out to be more socio-technically emphasised, because I felt that the technology in itself was a smaller problem than the dissemination of some type of solar cookers.

To give the occasional reader some background to the subject I included a brief retrospective view of (some) previous solar cooking projects, and also an estimate of the fuel saving potential of solar cookers. The chapter on the transfer of technology from North to South seems to be just a scratch on a vast surface. I must admit, that its theory is the weakest part of my knowledge in this thesis because it has not been included in my formal studies. Still, it is the area I am the most interested in for the future; the connection of theory and practise. I love to work in the field of solar energy, although I do not know if solar cookers will ever be a breakthrough or not.

The thermodynamical review area alone would have been enough for a thesis. Unfortunately, we do not have valid scientific research on solar cookers in Finland, and therefore I had to lean on the literature. I hope I managed to somehow collect covering information of the most important factors concerning the operation and design of a solar box cooker. Likewise, I did not make many measurements while in Namibia. The reason for this was that I was totally overbooked in teaching people how to build and use solar box cookers. Besides, the users' earlier experiences proved the model we used to be good, so I just mainly collected information for minor modifications.

Still, the meaning of this thesis is not to be a complete manual about everything concerning solar cookers and their dissemination. Instead I had in mind to introduce a solar cooker project; its history, planning, implementation and evaluation. I used my best knowledge, common sense and intuition, all together, in estimating which factors need to be taken into account when carrying out this kind of project. I have learned enormously from doing it, both in Namibia from working with those wonderful people, and in Finland while planning the project and finally writing the thesis. For the latter I am in deep dept to my instructor, Mrs. Anneli Pulkkis, who has helped, guided, critisised and encouraged me, especially in shifting my thoughts and the way of writing this thesis from an individual point of view to the institutional point of view.

I wanted to write a thesis which would connect three things: solar energy, developing countries and the interface between the Northern technology and the Southern reality. The latter is the point where my studies of Industrial Psychology could be utilised. After all, people tend to be similar everywhere in the world, when it comes to new technical devices and their use. If they consider the new technology is useful for them, according to their own criteria, they will accept the idea easier. If not, it will be very difficult, or impossible to make a break-through. Anyway, it is those people's own decicion. My role is to help them by offering my skills and information, if they want it. In a way I could say that this thesis is a beginning for me. I could do something I believe is good to do; even if solar cookers would not be THE thing for me in the future, they are a practical and attainable means of rising the quality of life for many people.


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Appendix 1. Map of Namibia and general information about the country

Fig. A1. A map of Namibia. Ongwediva is located in the north in the Owambo area, 10 km. east of Oshakati

Note: This information is based on several sources. Some of it is already out of date, but due to lack of more valid data I present this information here as a reference (Sources: Erkkilä and Siiskonen, 1992, The World Factbook 1994 by the CIA (USA), private conversations with Dr. Strijdom, in Namibia).

Namibia is a republic (became independent March 21st, 1990, president Samuel (Sam) Daniel Nujoma) located in the southwestern corner of Africa. It is bounded on the north by Angola, Zambia and Zimbabwe, on the east by Botswana, on the south and southeast by the Republic of South Africa, and on the west by the Atlantic Ocean. Namibian climate is mainly desert; hot, dry; rainfall sparse and erratic. Terrain is mostly high plateau; the Namib Desert along the coast; the Kalahari Desert in east. Land use: arable land 1%, permanent crops 0%, meadows and pastures 64%, forest and woodland 22%, other 13%. The territory of Namibia covers an area of 82.4 million ha. Namibia is almost three and half times the size of the United Kingdom and two and the half times the size of Finland. Namibia covers nearly 3 per cent of the total land area of Africa and contains about 0.2 per cent of the whole population of Africa. About 60 per cent of the population live in the northern part of the country (about 50 per cent of the population belong to the Ovambo tribe). Current estimates place the present population at 1.8 million, and the population growth rate is estimated to be 3.5 per cent. The average population density in Namibia is only 1.5-1.7 inhabitants per km2 (one tenth of the average in Africa). The largest urban city is Windhoek, which is the capital of Namibia. The official language of Namibia is English. Several other languages are spoken, e.g., Oshiwambo, Herero, Nama, Bushman (San), Afrikaans and German.

The Namibian GDP was officially estimated to be US $ 1 000 per capita in 1991. Namibian agriculture accounts for about 15% of the GDP; mostly subsistence farming; livestock raising the major source of cash income; crops - millet, sorghum, peanuts; fishing. Namibia is not self-sufficient in food. The Namibian economy is heavily dependent on the mining industry to extract and process minerals for export. Mining accounts for almost 25% of the GDP. Namibia is the fourth-largest exporter of nonfuel minerals in Africa and the world's fifth-largest producer of uranium. Alluvial diamond deposits are among the richest in the world, making Namibia a primary source for gem-quality diamonds. Namibia also produces large quantities of lead, zinc, tin, silver, and tungsten. More than half the population depends on agriculture (largely subsistence agriculture) for its livelihood.