The Seminoe Pumped Storage project is a proposed “reservoir-based energy storage project” that is being touted as a “modern energy hub for Wyoming wind energy”, with an upper reservoir proposed to be built on Bureau of Land Management lands, and Seminoe Reservoir (Bureau of Reclamation facility) to be used as the system’s lower reservoir.  

The project is being proposed by the project developer, rPlus Hydro (a Utah LLC), as an open-loop system. Open-loop systems such as the one proposed for Seminoe are capable of releasing significant quantities of water between reservoirs multiple times a day, altering the temperature stratification of the lower reservoir and increasing turbidity. Closed-loop systems have been studied by the Pacific Northwest National Laboratory to generally have lower environmental impacts than open-loop projects.

Concerns brought forward by federal, state, and local agencies, nonprofit organizations, and the public during the Federal Energy Regulatory Commission (FERC) scoping process include: long-term effects on water quality; entrainment of fish in Seminoe Reservoir; sport and ice fishing impacts in Seminoe Reservoir; premature dam failure; emergency spillway design inadequacies; North Platte system water rights; wetland loss; impacts to mule deer, bighorn sheep and sage grouse habitat; long-term impacts to recreation including fishing and hunting; construction-related impacts; and socioeconomic impacts to surrounding communities.