Status of flat-plate photovoltaic systems for applications in developing countries

This paper discusses the status of flat-plate photovoltaic (PV) system technology, performance and cost for applications in developing countries. Comparison of key electrical service performance factors is made between PV and conventional generating systems. PV module reliability results from 23 field tests are summarized and the effect of failure on system performance is discussed. Cost algorithms, drawn from historial data, are defined and applied to obtain PV system selling price as a function of worst-month insolation and for several values of loss-of-energy-probability, (LOEP), an index of performance. Comparison is made of levelized energy cost between PV and diesel-generator systems. Projections of PV system selling price, major component costs and system levelized energy cost to the mid-1980s and 1990s are displayed and the implications discussed. It was concluded that PV system technical viability had been confirmed and commercial development is well advanced. PV system electrical service performance is generally superior to service performance provided by the electric grid or diesel in rural and remote areas. At present, for many applications having an annual electrical demand of up to 4 to 10 MWH, the levelized energy cost of PV systems in regions of good insolation is less than for diesel generators. Within 20 yr, if cost projections are borne out, photovoltaics will become the least expensive and most reliable source for most decentralized electric power in the developing world.