1. Introduction

Hopes: Some people see cooking with solar energy as a neat way to alleviate or even solve several development problems at once:

- women's exposure to unhealthful cooking conditions, and their hard, time-consuming work of collecting fuel

- shortage of firewood (read: the energy crisis of poor people in the Third World) with such devastating ecological consequences as deforestation, rampant soil erosion and subsequent desertification

- dependence on nonrenewable sources of energy, with attendant balance-of-payment problems for the nation as a whole

- a lack of future-oriented technologies that would be fit for small-scale application and therefore (could) have a gigantic global market.

Solar cooking also touches upon a basic need: nutrition. At first glance, cooking with solar energy has the appearance of a development-political stroke of luck.

Disappointments: While various solar cookers have been developed and tested, practically all attempts to get appreciable numbers of them put into actual service have been unsuccessful. Are solar cookers still technically immature, or do they constitute inappropriate technology? Why are they (still) not being accepted by people in developing countries?

Background: This report attempts to answer such questions. In addition to the results of an intensive study of pertinent literature, the report is based mainly on a cross-section analysis conducted on behalf of Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH* and the German Appropriate Technology Exchange (GATE). The analysis, conducted by the authors themselves in 1986/87, included taking stock by way of a worldwide postal survey - of all solar cookers developed by 1986/87, in addition to diagnosing solar cooker projects in India, Kenya, Mali, Pakistan and the Sudan. The cross-section analysis attaches special importance to the socioeconomic, psychosocial and sociocultural conditions of acceptance, although the technical aspects are also given due attention, of course.

Intentions: This report addresses development-political decision-makers as well as engineers and technicians engaged in innovative work aimed at harnessing solar energy. Its main objective is to draw attention to the many socioeconomic, sociocultural and psychosocial technical framework conditions that can be decisive for the dissemination of new ideas and/or the diffusion of innovations. In that sense, this report assesses the secondary effects of a soft technology and analyses its prerequisites, prospects and risks. The following interdependences are of crucial importance:

- Poverty: "A central function of development aid, one which in the past has been inadequately realized, is to reach the poorest social strata" /24,7/**. "Development aid provided by the Federal
Republic of Germany is directed primarily at the poor social strata" /24,20/. Thus read the Federal German Government's currently valid guidelines on development policy. Accordingly, any solar cooker project must stand judgment with regard to how much it can contribute toward those ends.

- Sources of energy: Substituting indigenous energy for imported energy can be very helpful for improving a country's balance of payments by lessening its dependences, reducing its foreign-exchange shortage and easing its foreign-debt burden. This is all very important for the country's overall economy. But when poor people are the subject of discussion, the question of household energy supplies is the crucial point ... "Cooperation in the field of new energy technologies within the energy sector in general as a means of expanding the technological capabilities of developing countries" /24,29/, which the Government of the Federal Republic of Germany both calls for and promotes, must - in order to be in line with that country's prime development-political objective - place first emphasis on decentralized forms of energy supply, "which stands to improve the living conditions of large sections of the population, first and foremost the rural population, while preserving natural resources, particularly forests and soil fertility. A broad effect should be achieved by offering uncomplicated equipment and appliances that can be kept in good working order by the native users and which prove to be cost-efficient at their respective places of use. To that end, the aid of suitable national-scale technoscientific and/or application-oriented sponsors is enlisted for improving basically economical technologies, field testing of technically mature technologies for inservice economy, and ascertaining the actual degree of sociocultural acceptance'' /22,22/. Thus stipulates the Federal Government's Program for Cooperation with Developing Countries in the field of energy technology.

- Diet: Some important forms of energy are often overlooked: manpower, for instance, i.e. the energy provided by human muscles and the energy content of the nourishment needed to replenish the strength of those muscles. Most people's thoughts tend to center on technical sources of energy. But when energy per se and its rational use are to be promoted via development-political considerations, then the links between primary, secondary and tertiary energies and between technically relevant and humanly relevant energies are necessarily of primary interest. In a joint statement, the Federal Ministry for Economic Cooperation (BMZ) and the Federal Ministry of Food, Agriculture and Forestry announced that the Federal Government attaches very special importance to "making a lasting, effective contribution toward improving the global nutritional situation and toward socioeconomic development in the Third World" /20, III. Solar cooker projects must be seen in that light and judged accordingly.

- Women: Practically everywhere, women, not men, do the cooking. Solar cooker projects therefore address women directly. Consequently, a general requirement for all measures is that they "contribute directly toward improving the situation of women in their role as housewife/mother and producer/employee'' and toward ''advancing their social self-determination and political participation" /43,23/, most notably through

- lightening their household workload
- improving their housekeeping methods
- family health and childcare
- promoting the economic/financial activities of women /43,23ff/.

Solar cooker projects therefore should display a high degree of relevance to women. Whether or not that is the case, and the extent to which solar cookers might even aggravate women's work, are issues of special importance.

- Technologies: Solar cookers are an example of technological innovation. In view of widespread negative experience in the past, appropriate technology is in increasingly high demand for the developing countries "Robustness, durability and easy maintenance" /49,33/ are prime criteria. Research and development in this area must include comprehensive field tests to determine how well or poorly a given technology fits into its overall system context: environment, engineering, economy, social aspects, politics, culture, values; assessing the impact of technology is a basic element and concomitant aspect of developing appropriate technologies/ as called for by GTZ /49,38/. For solar cookers, too, the main question is: Is the technology appropriate, i.e. does it fit the needs and living conditions of the target groups of development policy? Thus, according to the development-political guidelines followed by the government of the Federal Republic of
Germany, "development policy must have as close a tie-in as possible to the given cultural and social situation" /24,12/. Systems: Technological innovation needs integration into political, socioeconomic, cultural and ecological networks. To limit one's investigation to certain predetermined parts of that network would be scientifically unjustifiable. In other words, any evaluation must aim first for breadth - and even sacrifice depth if need be - in order to gain relevance. Then, in its second phase, it may begin to address other, rationally chosen matters. Since evaluative research on solar cookers is just getting started, its systematic, exemplary expansion in the sense of a technology impact assessment would be a worthwhile task for future development-political research.