The heart of solar photovoltaic (PV) modules is a solid-state semiconductor device called a "solar cell" that converts sunlight into direct-current electricity. The technology was initially developed for the space program in the 1950s topower the first satellites. PV's extreme simplicity, high reliability, and durability were keys for space applications but its high cost precluded most other uses. The energy crisis in the early 1970s renewed mainstream interest in PV, and its development expanded to include terrestrial power applications. At that time, PV's RD goals and funding sources shifted away from the space program to private/public sector collaborative efforts, which over the past 30 years resulted in a 95 decrease in module costs and a concurrent doubling in the typical PV system energy conversion efficiency.
展开▼
