Energy Storage at Groundwater Banks: Fid-Bau Portal

Energy Storage at Groundwater Banks

House, Lon W. / Beuhler, Mark / Ahinga, Zachary / Iqbal, Naheed / Ta, Tommy

This study investigated adding energy storage (pumped storage) at a groundwater bank, Willow Springs Water Bank, in Southern California. Two different technologies were evaluated. Aquifer pumped hydro (APH) uses reversible pump turbines, the aquifer as the lower storage reservoir, and a surface storage reservoir as the upper reservoir. APH and peak hour pumped storage (PHPS) can be used with or without demand response (DR), which deliberately curtails pumping to limit energy use at times when energy use and prices are high and shifts pumping to times when energy use and prices are lower. PHPS uses a surface storage reservoir as the lower reservoir, an upper elevation surface reservoir as the upper reservoir, and pumps and a hydroelectric generator to connect the two. Three different water bank operating modes were assessed (wet year—recharge, dry year—extraction, and neutral year—pumped storage). The results of the analysis are that APH was not cost‐effective. PHPS was, but the ability to curtail/adjust pumping and participate in DR was the most valuable resource, more valuable than the ability to generate electricity.