CHAPTER 1

INTRODUCTION

Of the many problems which a new project for milk collection and processing faces in a developing country, the most important are the shortage of the necessary capital and the difficulty in keeping all costs at a sufficiently low level. The specific costs of collection, transport and processing are usually abnormally high because supplies of milk are inadequate to utilize fully the installed machinery. Small quantities of milk delivered by individual producers, long distances between the production areas and the markets, bad road conditions and high ambient temperatures make the development of a dairy industry a particularly difficult task.

Dairy development policies in such countries are most often based on foreign patterns. They include establishment of a number of collecting centres and processing plants whose basic feature is the technology prevailing in industrialized countries. That technology is marked by processing costs often too high for markets in developing countries and machinery often too complicated for locally available skills. The capacity of equipment normally available often greatly exceeds the quantity of milk which can be obtained, particularly in the early stages of development.

In recent years new trends are becoming evident in applying technology to food processing in developing countries. This involves simple processes better adapted to the special needs of these markets. These ideas now need study and applied research, primarily by establishing pilot schemes in which feasible projects are tested. Consistent with these trends is the examination of the feasibility of using solar energy for small-scale operations.

The well-known world energy crisis justifies active search for alternative energy sources of which solar energy is a particularly attractive choice in countries situated in the sunnier parts of the world. If utilization of this energy is feasible and could be combined with simple technologies, the aim of reducing capital inputs and processing costs might well be met.

Conventional fossil fuels from known resources are estimated to last, at present consumption trends, for:

While these estimates may be conservative because future discoveries and more efficient methods of utilization may extend them, such resources are finite and their cost must steadily increase. The technology of nuclear energy is still in its early stages but where it is based on naturally occurring elements such as uranium it is subject to similar limitations.

The solar energy reaching the world's surface is practically inexhaustible and, in 1980, was about 20 000 times greater than all the manconverted energy from all fuels. Technologies for trapping solar energy and converting it into industrially useful forms are undergoing development, and research and development work on this subject enjoys high priority all over the world. Modern processing industries, however, including food processing require a continuous energy supply. This presents serious problems in the application of solar energy systems which, by their nature, can accumulate energy only during daylight. Difficulties in resolving the problem of storage of the accumulated energy and making this continuously available in the required quantities at the necessary levels are the main reasons why solar systems have not yet become an attractive proposition in modern industry. However, there is a chance that small-scale industries will adapt themselves much more quickly to energy supply from solar systems than would be possible for large-scale operations.

Small-scale industries already have difficulty in applying modern technologies due mostly to complicated and expensive equipment with capacities far exceeding those required by small plants. The latter need new and better adapted designs. Their energy requirements are relatively small and can be compared to those for domestic use such as water heating and air conditioning where application of solar energy has already begun.

No attempt has been made to present an exhaustive survey of the solar systems currently available or of research and development work currently in progress. The relevant literature is very rich indeed and it seems unnecessary to repeat it in this study. However, a bibliography is included. The survey of solar systems given in Chapter 3 is therefore limited to basic principles and information related to their feasibility in smallscale milk schemes.

Chapters 4 and 5 provide suggestions for pilot projects which could be successful for schemes up to 1 600 litres of milk per day. There is no single ideal solution and only by pursuing projects such as those suggested can real progress be achieved.