Recommended, but not required:

1. J. O. McVeigh, "Sun Power: An Introduction to the Applications of Solar Energy," Pergamon Press: Pergamon International Library of Science, Technology Engineering and Social Studies: 1977, 208 pp., 250 x 176 mm, https://www.mragheb.com/Ragheb%20Sun%20Power.pdf
2. John A. Duffie and William E. Beckman, "Solar Energy Thermal Processes," 1974, 386 pp., 250 x 176 mm, John Wiley & Sons, Inc., Wiley-Interscience Publication.