This study presents the life cycle energy consumption, emissions, and environmental impacts of flat plate and evacuated tube domestic solar hot water system manufactured and used in Thailand. The results presented in this article show that the life cycle energy consumption for the flat plate system is 5% lower than that of evacuated tube system. The application of flat plate system is useful over evacuated tube system for 8 out of 12 emissions are examined. The global warming potential is 3% lower for the flat plate system than that of evacuated tube system. The average reduction of energy consumption and environmental impact by reusing materials are 65 and 50%, respectively for the flat plate and evacuated tube system. A comparative study with other systems available in the literatures based on few performance indicators shows that the energetic and environmental performance of domestic solar hot water system in Thailand is quite attractive. This article is useful to enhance the local production in line with energy and environmental sustainability in home and Asian neighboring countries. © 2015 American Institute of Chemical Engineers Environ Prog, 35: 271–283, 2016