This book presents the papers from the 2nd International Conference on Sustainable Technologies, Energies and Materials (STEM 2025) held during February 19-21 in Bangkok, Thailand. The papers discuss the latest developments in sustainable technologies, renewable energy sources, and eco-friendly materials with the aim to address global challenges related to sustainability. Topics covered include green energy solutions, sustainable materials, waste management, energy efficiency, and the integration of sustainable practices in various industries. Its content caters to researchers, academics, students, and industry practitioners who are interested in the development of technologies and materials that promote environmental stewardship and sustainable development.