This is the second volume of a 3-volume history of solar power generating systems covering the approximately 50 years of research and development surrounding the energy crisis of 1973. Volume 1 covered solar-thermal systems. The present volume covers photovoltaic systems in the 20th century. Volume 3 will cover photovoltaic developments from the start of the 21st century. The history is based upon keynote lectures given by international specialists at the Sede Boqer Symposia on Solar Electric Power Production, a series that commenced in 1986. The lectures document many technical details that have become hard to find, including some pertaining to technologies that were successfully demonstrated but subsequently discontinued owing to their not having been deemed to be cost-effective at the time. However, in the event that different economic considerations may ensue, these volumes can provide a valuable starting point, including references, for the re-investigation of some of those once abandoned ideas.