•AE mechanisms in RE systems were firstly classified.•AE sensors, signal processing and fault diagnosis and leading advances across representative RE fields were summarized.•Challenges and development trends of AE in RE systems were proposed. Renewable energy (RE) does not pollute environment at the point of energy generation, and generally has a much lower pollution footprint than traditional energy from installing to decommissioning, and can diversify the power generation technology. Because of the high operation and maintenance (O&M) costs, it is necessary to build remote, online, credible monitoring and inspection techniques. Acoustic emission (AE) technology is effective and efficient to monitor and detect mechanical damage, deterioration, and failure, etc. Over the recent years, a remarkable number of scientific papers demonstrate the capability of AE in nondestructive testing (NDT), structure health monitoring (SHM), condition monitoring (CM) and fault diagnosis for RE generation, transmission, transformation and storage systems. Most of work focusing on detection principle, sensor design, signal processing and diagnosis has provided a lot of valuable contributions for academic and industrial fields. Nevertheless, all this valuable information is scattered over many sub-fields of literature, and the knowledge is not systematic. This paper is dedicated to analyze the different AE principles in RE systems, and to comprehensively summarize and clearly highlight the advanced methods and challenges. Development trends in research, application and standard are also discussed and suggested.