Low-head hydropower as a reserve power source for wind power

Abstract

Wind power generation faces intermittency challenges, typically requiring reserve power generation sources burning fossil fuels to maintain reliability of the electricity grid in the event of a decrease in wind. This study proposes an alternative hypothesis: that hydropower turbines installed at low-head dams can provide similar reserve power generation to support wind, thereby avoiding the externalities associated with fossil-fuel plants and conventional hydropower. Low-head dams, common across the United States, are used for flood control, securing municipal water supplies, and providing ample water depth for recreation. As a case study, hydropower potential at 13 such dams along a 150-kilometer reach of the Fox River (Northeastern Illinois, USA) was estimated using a HEC-RAS model calibrated with U.S. Geological Survey data. The output of the model was then analyzed to determine the capacity of the system and gauge its reliability both as a standalone generator and as a component in a coupled wind-hydropower system. Findings revealed that economic, environmental, and regulatory factors all affected the implementation of this low-head hydropower system. The system was found to perform reliably over a five-year time period in spite of significant long-term fluctuations in streamflow, thereby enabling it to offset the short-term variability of wind power. However, combining the low-head hydropower system with wind power limits the reliable output of the entire system to the lowest amount of power generated by the low-head hydropower system, regardless of how much wind power is deployed. The low-head hydropower system's relatively small capacity and inauspicious cost-benefit ratio suggest that this low-head hydropower system would be best suited for local applications rather than grid-scale operations, especially if environmental and regulatory considerations are included.