During 11-14 December 2019, JGSEE-CEE at KMUTT, Thailand in collaboration with the Center of Inter-Integration (CII, NIU), Taiwan, the Centre for Energy Sciences, University of Malaya and the Center for Vehicular Technology (UTAR), Malaysia, the Research Center of Energy Conservation for New Generation of Residential, Commercial, and Industrial Sectors (NTUT), Taiwan, and the United Nations Environment Program (UNEP) organised the International Conference on Sustainable Energy and Green Technology 2019 (SEGT 2019) at the Millennium Hilton Bangkok in Thailand. During the opening ceremony, welcome remarks were delivered by Assoc Prof Dr Suneerat Fukuda, Director of JGSEE, Ms Isabelle Louis, Deputy Regional Director and Deputy Regional Representative for Asia and the Pacific of the United Nations Environment Program (UNEP), and Assoc Prof Dr Suvit Tia, President of KMUTT, who also delivered an opening address. Plenary keynote presentations were delivered by Prof Ibrahim Dincer, Ontario Tech University, Canada and Prof Jiří Jaromír Klemeš, Brno University of Technology, Czech Republic. Overall 300 papers were presented at SEGT 2019 in parallel sessions that also included 3 special sessions coordinated by the United Nations Environment Programme (UNEP). The event was a great success involving the contribution from over 400 participants worldwide.