Ultra high cell efficiency on the path towards fossil-competitive PV economics

Introduction In exploring the path to ultra high efficiency solar cells, an important question we must ask ourselves is: “What will we do when we get there?” The path itself will hopefully open up an increasing number of niche markets that will keep Industry interested in PV along the way. However, if ultimately, PV will not be able to compete economically with fossil fuel, this technology will have failed its societal obligations. And, as I shall emphasize, high cell efficiency is not the whole story. In this talk I would like to take as a bench-mark, the present-day economic performance of a typical grid-connected PV system, located at an optimal site in terms of energy generation per capital expenditure (i.e. kWh/kWp). This bench-mark will point us in two possible directions, indicating the cost bounds that must be met in each case. It will thus become clear that if cost-effectiveness is the ultimate goal, at least two qualitatively different paths to ultra high efficiency should be considered.