Hydropower is a major renewable energy source, and improving the operational efficiency of existing hydropower systems has become essential. The objectives of this study are to (a) develop a specific energy-based hydropower efficiency method at a daily scale; (b) establish a comparable and general indicator for hydropower reservoir operation planning; (c) propose an operational strategy and practical decision support tool that maximizes generation performance under identical generation discharge constraints. We develop a method to estimate specific energy for different power output levels using the power output and discharge relationship and construct operating combinations based on the output range with the highest specific energy. We applied it to a single day and extended it to an entire month, using Hwacheon hydropower dam in South Korea. The results show that the daily increase ranged from 2.73 to 18.4 MWh, and the total monthly cumulative increase was 177.39 MWh. This corresponds to a potential increase of about 2.1 GWh in electricity generation. This approach achieves higher energy generation than observed operational performance. A specific energy-based operational strategy can consistently improve generation performance across varying hydrologic conditions. Specific energy provides a practical decision support tool for improving generation performance under water resource constraints.
Lee et al. (Thu,) studied this question.