PrefaceAt first, on behalf of the organizing committee of the 2019 3nd International Workshop on Renewable Energy and Development (IWRED 2019), I would like to express our deepest appreciation to all the participants who have attended the conference IWRED 2019 and have made great contribution to the conference. Besides, I strongly appreciate the contribution of the authors, who submitted valuable papers and agreed to do successive revisions of their papers, following the recommendations received from the reviewers.IWRED 2019 is organized by Taiyuan University of Technology, China. It aimed to bring together experts in renewable energy and development, to exchange ideas and make new connections to extend and develop partnerships between the researchers from home and abroad. This conference provided an excellent opportunity for everyone involved to learn and discuss about sustainable development and green technology to the following areas:Renewable Energy and Environmental Protection MaterialsEnergy Efficient Systems and Optimization TheoryPower System TechnologyGreen Building and Construction EngineeringSustainable Energy and Environment