The intense current interest in the development of solar energy as a viable energy alternative comes as no surprise in view of the widespread awareness of impending world-wide energy shortages. After all, the magnitude of energy available from the sun is impressive, its diffuseness and intermittent nature notwithstanding. The fact that, as a source, it represents a constant and inex haustible supply of energy is alluring. The fact that most solar application schemes are nonpolluting in nature is an attractive bonus. In spite of these impressive attributes, research and development in the area...