Amazing Photovoltaics: From Research Curiosity to Technology Reality

The recent technical, commercial, and market progress of photovoltaics (PV) has been amazing. This paper examines the progress of PV technology over the past 70 years from a research curiosity to a valid electricity source—from the viewpoint and insights of someone who has lived the early PV evolution to the current revolution. PV has emerged as a world’s primary electric power candidate to meet economic, reliability, climate, and versatility expectations. In early 2022, the world cumulative installations surpassed 1-TW. This year, the PV industry is shipping more than one-third terawatt more product into the world markets. Prices for PV modules are near $0.40 USD (2023 USD) in most markets. Worldwide, PV accounted for more than 60% of the electric power added to our grids the past 2 years. Factories have production capacities exceeding 10-MW/year. However, the beginnings of this technology were somewhat modest, starting with the announcement of the first modern research solar cell by Bell Telephone Laboratories in 1954 having 6% solar conversion efficiency, ~2 cm2 in area, producing about 10 mW of power. In contrast, current commercial PV cells in the range 20–25% efficiency are common, with areas above 20 cm2, and fashioned into modules delivering 500–700 Wp. The technology advancements from simple p-n junctions to current complex cell structures, from monofacial to bifacial devices, and the ability to engineer at the nanoscale to optimize the performances at the macroscale are exampled. Innovations with artificial intelligence (AI) or machine learning (ML) that have accelerated the progress of every step in the value chain of PV technology from materials through systems are highlighted. And the fact that PV research and development are not “over” is emphasized—with innovation driving this technology toward its next levels to meet the expanding requirements for our coming 100% renewable energy future. Recent R&D advancements are discussed including high-efficiency hybrid perovskite and some other thin-film technologies that are at the cusp of high-impact commercial reality—giving evidence for continued progress. Also discussed are some of the barriers encountered and mistakes made over this long timeframe in bringing this technology to reality. The current trend in diversifying manufacturing locations is discussed as mandatory for continued PV cost reductions and product delivery. And the potential for expansion of PV from mainly the electric power sector into buildings and mobility applications is forecast. PV advancements have been amazing—as has living and experiencing its birth and inclusion into our daily lives.