His main research interest is on Grid Integration of Renewable Energy (GIRE). In this research topic, he has been leading the research in two themes: Planning and Operational Planning of grid integration of renewable energy. His research has been used by industries and received high citations. Based on his research, he published over 320 articles, including one book, eight book chapters, technical reports, refereed journal and conference papers.

He had supervised 29 Ph.D. students (UQ, CQU, UNSW, UNITEN and AIT), 50 research Masters (at AIT) and over 170 thesis project students at both undergraduate and postgraduate levels to successful completion. He had been involved in over 30 projects (research, teaching and learning) with a total budget of over 3.6 million AU$, as a principal or co-principal investigator. His recent grants are from Australian Research Council (ARC), Government of India, Indonesia and Malaysisa and Sterling Wilson Company. Previous projects were funded by European Union (EU) and other international donor agencies such as Swedish International Development Agency (Sida), NORAD, ARC, CSIRO and Australian Power Institute (API). His research network includes most of the member nations in ASEAN, other Asian countries such as India, China, Bangladesh, Sri Lanka and a number of European countries (France, Germany, Sweden, Norway, Finland, Denmark, The Netherlands).