Dr. O.S. Sastry obtained his Doctor of Philosophy (Ph.D.) in physics from India's most prominent Thin Film Laboratory, Department of Physics from the prestigious Indian Institute of Technology, Delhi. During the initial period of his career, he joined Defense Research Development Organization (DRDO) at Visakhapatnam. In 1989 he joined the Ministry of New and Renewable Energy, Government of India as a senior scientific officer, and involved in countries` Solar Energy Programme execution. During 1992 he joined Solar Energy Center (SEC) as in-charge of National Photovoltaic Test Facility. He is responsible for design, establishment and accreditation of the photo voltaic test facility (PVTF) of SEC as per IS 17025, quality system of NABL. He is also responsible for setting, development and up-gradation of additional test centers for PV module and systems testing across the country. He has also established SPV modules outdoor test beds for long term performance evaluation of different PV technologies at SEC. As a part of long term performance of PV modules he also executed joint collaborative projects with NREL, USA and AIST Japan. He is an accomplished technical expert for technical auditing testing laboratories for PV modules and systems. He is also the technical member of the BISET-28 committee for development of Indian SPV standards. At present he is reviewing the IEC standards with view to modify them to be suitable to Indian conditions. Dr. Sastry is responsible for all testing and certification activities in Solar Photovoltaics in the country. 

He is Project Leader from SEC in STAPP project, and is responsible for WP1 (Power and Energy Management) and WP6 (Performance and Potential). As a part of this he is establishing comprehensive test beds for long term performance, monitoring, evaluation and analysis for different technology PV modules.