The 2020 the 4th International Conference on Energy and Environmental Science (ICEES 2020) was held in Perth, Australia during January 8-10, 2020.The objectives of ICEES is to offer leading researchers, engineers and scientists in the domain of interest from around the world the opportunity to meet with colleagues and to provide a communication platform to exchange research ideas and share new knowledge, development and experiences in a friendly environment to gain the benefit from the latest developments in technology presented at the conference.ICEES2020 was held for 3 days including 3 keynote speeches and 4 authors’ presentation sessions. Three keynote speeches were delivered by Prof. Saad Mekhilef (IET Fellow) from University of Malaya, Malaysia; Prof. Danny Sutanto from University of Wollongong, Australia; Prof. Hee-Je Kim from Pusan National University, South Korea. Papers were presented in four sessions of the conference: 1) Energy Engineering and Sustainable Development, 2) Power System and Energy, 3) Battery Technology and Energy Storage Materials, and 4) Engineering Materials and Building Energy Consumption. Each presenter has 15 minutes (including Q&A).