By Elizabeth Ingram, Hydro Review content director
Stantec announced it has been selected by Missouri River Energy Services (MRES) to conduct a feasibility study for the 1,800-MW Gregory County Pumped Storage Project located on Lake Francis Case on the Missouri River, near Lucas, S.D.
The proposed project will provide increased energy resiliency and grid reliability, while also addressing intermittent power generated by wind and solar, and aligns with the global transition to more sustainable forms of energy generation.
As part of the feasibility study, Stantec will develop the project to 5% design and perform technical and cost evaluations that consider alternative layouts of principal structures, their types, and basic designs to provide a more specific indication of the technical feasibility of the site.
Governments around the world are turning to solar and wind power to help meet aggressive renewable energy targets, but grid operators face challenges when the sun isn’t shining or the wind isn’t blowing, Stantec said. Energy storage helps to quickly bring large amounts of power online to fill the gaps.
“Energy storage options like pumped storage are a critical component of a resilient and sustainable energy future,” said Mario Finis, executive vice president for Stantec’s Energy & Resources business. “We are privileged to partner again with Missouri River Energy Services, a supplier of reliable cost-effective energy services, in studying the feasibility of this project, which will play a critical role in achieving their long-term renewable energy goals.”
For over a decade, Stantec has worked with MRES as owner’s engineer and designer of record for the 55-MW Red Rock Hydroelectric Project on the Des Moines River near Pella, Iowa. The project is now producing a portion of the power for 61 MRES communities in four states. The Red Rock Dam was originally built by the U.S. Army Corps of Engineers in the 1960s for flood control and recreation purposes.
Per the MRES website and dated February 2021:
The Federal Energy Regulatory Commission (FERC) has issued a preliminary permit to the Western Minnesota Municipal Power Agency (WMMPA) to study a pumped storage hydroelectric project along the Missouri River in south central South Dakota. (WMMPA provides financing for generation and transmission facilities that are used to serve the wholesale electricity needs of 61 MRES member municipalities.) The permit is to study the feasibility of the Gregory County Pumped Storage Project (GCPS) to be located on Lake Francis Case on the Missouri River in Gregory, Charles Mix, and Brule Counties.
If built, the Gregory County Pumped Storage Project would consist of a new upper reservoir, a powerhouse containing turbine/pump units, a new tailrace from the powerhouse to Lake Francis Case, a new substation and transmission lines, and other necessary facilities. This proposed pump storage project would pump water into an upper reservoir, and then use the water to operate several hydroelectric generation units when needed. This project could provide important energy services in a multi-state region and play a vital role in integrating wind and solar resources. While still under study, preliminary estimates are that there will be 31,200 megawatt-hours of energy storage, or 26 hours of operation at 1,200 megawatts at maximum — enough energy to meet the annual electric needs of 250,000 to 300,000 average homes.