The water-energy-climate nexus concept of “Hydrobattery”: Storing excess Variable Renewable Energy (VRE) at the Canyon Ferry Dam

Hydropower is the renewable energy with the highest power production worldwide. At the same time the output flow of the water that is being used for hydroelectric power production can fluctuate significantly. The ability to “recharge” the dams with water from excess variable renewable energy technologies (VRE) can be used for storage and as a buffer for smoothing the production peaks of VRE. This study presented the idea of the “Hydrobattery” scheme which combines the concepts of “open-loop” and “closed-loop” pumped storage technologies along with the concept of energy storage and water recirculation. The Canyon Ferry Dam was used as a case study and water was modelled to be recirculating back to the Dam from the Helena Valley reservoir. The hydropower production from the Canyon Ferry Dam is below the nominal value of 50 MW and has fluctuated from 34.74 MW up to 41.46 MW for the period between 2014 and 2018. The application of “Hydrobattery” would be able to increase the power output by 2.39–3.39 MW of additional power, and an increase of power production between 5.7% and 9.7%. Also, the concept of “Hydrobattery” can be used as a potential water management system for connected water reservoirs.