Study on the academic landscape of hydropower: A citation-analysis based method and its application

Hydropower, with characteristics of superior storage capacity and speedy response, can meet sudden fluctuations electricity demand. And its generation capacity could be doubled by 2050 according to IEA's recent estimation. Besides, hydropower doesn't require innovative technologies, and can be operated with minimal cost. However, no big picture of knowledge related to hydropower can be found in the preceding research. This paper aims to figure out the academic landscape in this field by analyzing the citation network of papers published in academic journals. We collected 7,521 target papers using specific search query from Web of Science. By utilizing a topological based method, all the papers were categorized into clusters by their own characteristic topics. Results show the existence of 6 principal research clusters: Renewable energy, Optimization of system operation, Environmental issues (greenhouse-gas emission), Environmental issues (fish management), Environmental issues (sediment) and Pumped hydro storage systems. As the keywords of some major clusters seem to be general, in-depth sub-clusters analysis was also conducted to gain better knowledge of those clusters. Combing the analysis results, (sub)clusters related to pumped-storage and small hydropower are considered to be developing, as indicated by the average publication year of papers and recent increasing trend.