This directory is designed to help the researcher and developer, the manufacturer and distributor, and the general public communicate together on a mutually beneficial basis. Its content covers the wide scope of solar energy activity in the United States primarily, but also in other countries, at the academic, governmental, and industrial levels. This survey consists of five major sections: Section 1, A Compilation of Computerized Data, provides descriptions of the interests, activities, or products of particular individuals, companies, or organizations; Section 2, An Inventory of Solar Projects, is a compilation of brief descriptions of solar heated and/or cooled buildings presently in existence, under construction, or planned for the near future; Section 3, An Annotated Bibliography, surveys the type of published material available on the subject of solar energy; Section 4, Appendices, includes Abbreviations, Late Additions, NSF/RANN Solar Energy Research Grants and Contracts in Fiscal Year 1974, Solar Energy Legislation, Solar Energy Courses, Money, and Environmental Actions of Colorado; and Sections 5 and 6, Indices for Section 1. Section 5 is an index of all companies and organizations and Section 6 is a listing of all individuals listed. Instructions for the use of each section are provided in the text. (BT)