Hydropower operation in future power grid with various renewable power integration

•The study aims to understand the role of hydropower in a changing U.S. power grid with increasing levels of renewable using a production cost model.•Hydropower dispatch follows the net load pattern in all seasons providing higher ramping to compensate for VRE generation variability.•Hydropower revenue is sensitive to regional VRE contribution levels and hydrologic variation, and higher revenue potential by supplying various grid services.•Flexible hydropower operation with variable capacity factors and increased ramping noted in results might not be feasible with other water use and environmental constraints.