The 3rd International Conference of Sustainable and Environmental Technology 2023 and Regional Conference on Environmental Technology 2023 (26-27 September 2023, Malaysia) on the theme: "Innovative Solutions for a Sustainable Future" were aimed to reflect the latest research results of the cutting-edge technologies and methodologies for promoting sustainability in energy and environmental engineering. The conferences provided researchers and practitioners a platform to share knowledge and research results on renewable energy, climate change mitigation, and environmental conservation. The research focused on the development of innovative solutions to enhance energy efficiency, reduce carbon emissions, and promote circular economy practices. The events have encouraged interdisciplinary collaboration, integrating science and technology to address global sustainability challenges.