Introduction

Abstract

A solar energy system should seek to provide the optimal combination of efficient performance, low initial and running costs, robustness and durability. A solar energy system consists, at a conceptual level, of components for energy collection, distribution and storage. These may be discrete items, or so inextricably linked as to be synonomous. The system components are linked to the solar energy resource and to the nature and pattern of energy utilisation. Furthermore, resource and utilisation are in turn linked when deciding the need the system is to meet. For example, in temperate climates, large solar energy availability would tend to mean that solar cooling would be required, and smaller solar energy availabilities would be harnessed for the accompanying heating requirements. To complicate matters further, both the input resource (i.e. patterns of insolation and ambient temperature) and the utilisation of output energy (e.g. patterns of hot water withdrawal from a solar energy water heater) are stochastic, though to what extent depends on the time-frame considered (i.e. hourly, daily, monthly or annual behaviour). In contrast, collection, distribution and storage phenomena are more often deterministic. These conceptual inter-relationships are illustrated schematically in Fig. 1.1.