Some thoughts on the future of photovoltaics

Abstract

Anyone's predictions for the future are intimately related with that person's perception of the world and his or her overall response to that perception. Personally, I am commit ted to the investigation, development and ultimate success of photovoltaics for a number of reasons: (1) it is a responsible way to react to energy needs for the future with the development of alternative renewable energy sources; (2) it promises many benefits for societies all over the world, perhaps as much for the developing nations as for the developed nations; (3) its use for destructive or inhumane purposes is not readily conceivable; (4) its development involves a host of fundamental and fascinating problems in materials science, solid state physics and device engineering, which form a challenging area for the application of understanding and for the education of a new generation of scientists and engineers. I believe also that the general adoption of photovoltaic technology could be a richly financially rewarding enterprise (thus also satisfying another of society's prime criteria) provided that political and social barriers can be overcome. The necessity of deriving appreciable quantities of energy from renewable energy resources, of which solar energy is the prime contributor, is a more certain characteristic of the future than is the survival of human civilization. It has been only 100 years since the chief source of energy in the world was the burning of wood. Developments of that century have led to an energy exploitation explosion so great that it seems certain to swallow up the energy reserves of oil and gas formed over the past ages in the next century, and the reserves of coal and uranium 235 over the next few centuries at the most conservative estimate. On the time scale of human history the curve of rate of use of fossil fuels is bell shaped with a halfwidth of a few hundred years, so small that it appears narrow indeed. On the scale of Earth's history such a curve would appear as no more than a ~ function separating the pre-fossil fuel era from the post-fossil fuel era. It is the partition between mankind's life-style with the renewable resources of the past, and mankind's life-style with adaptations and development of these same renewable resources in the future. The issue is serious. Given the present world political situation, it is not only the extreme pessimist who wonders whether mankind will prove adequate to the task of not destroying human civilization either in the midst of, or quite independent of, an energy crisis.