Pumped Storage Project explained
Studies will determine the feasibility of turning about 2,300-acres of farm/ranch land in South Dakota into a storage battery for wind and solar energy.
According to Joni Livingston of Missouri River Energy Services, the Gregory County Pumped Storage Project, in simple terms, would act like a huge battery using water to store the energy produced from regional resources. In times of abundant energy generated through wind towers and solar panels, water would be pumped from the Missouri River through an enclosed tunnel to the upper reservoir. Then when additional energy is needed, the water would be released where it would run down to the turbines where it can produce clean hydropower for the grid.
Missouri River Energy Services and MidAmerican Energy are working together to study the Gregory County Pumped Storage Project.
It is a huge project, located about five miles south of the Platte-Winner bridge. Depending on all studies, the costs will range between $5 to 10 billion. Built on the high bluffs on the west side of Lake Francis Case, the newly excavated upper reservoir would be created by installing an earthen embankment levee. This creates the opportunity for 700-plus feet of elevated difference needed to store energy. The reservoir itself would be 2,310 acres with additional acres needed for embankment and protected area. That will mean a total of 2,525 acres needed from tillable land and ranch land.
“Certainly, giving up their land is a number one concern for landowners who may perhaps sell part or all of their farm,” Livingston said. “It’s a hard thing to consider as some of the lands are generational. The parents want their kids to inherit. It will be a huge sacrifice, but our company will work with landowners to compensate them for this heritage land. Some will relocate or change their livelihood. Resources will be provided to make it right with them. That doesn’t encompass all of the sentimental value attached but we’ll try to do our best with each landowner, to give them the best deal that we can.”
Livingston emphasized that the company is seeking input from the community. “We’ve had listening sessions with landowners and stakeholders to gather information about studies which should be done before proceeding. We’re in the process of revising our study plan and will be submitting our new plan to the Federal Energy Regulatory Commission on Dec. 10 with meetings on Jan. 5 to review the plans.
“We are in the early stages as we look at the studies that need to be completed,” she said. “Nineteen different studies are identified to review every aspect of the project to understand the degree of impact and how to mitigate effects. A decision whether to move forward with the project will likely not be made until 2026. If at that time the project moves forward, there would be another two years of design and six years of construction. So, the earliest the project would be online would be in 2035.”
In addition, “We have talked with landowners in the impacted area where we will construct a transmission line from the powerhouse 22 miles east through Charles Mix County to connect into the electric system.”
Livingston said, “I might add that the project will be subject to property taxes, which is expected to generate significant tax revenues for the counties and school districts affected by the project. Those taxes, along with local spending during construction, can support roads, bridges, schools, local businesses, and more.”
She said this project will be cost effective as the price to generate wind energy is very low. The need to store wind and solar energy was shown when the electric grid failed due to severe weather conditions.
“This project can mitigate higher priced resources to stabilize utility prices in times of high demand. With the advent of regional transmission, this has changed energy dynamics. The life of the project, from 80 to 100 years, is what makes it cost-effective. That’s a much longer lifespan than traditional wind or solar projects. This reservoir would have enough capacity to store energy for 46 hours of operation at 1,800 megawatts or 82,800 megawatt-hours.”
Adding wind towers is not a part of this project as Livingston said the generation of additional wind energy is available in the region. On some days when the wind is blowing strong, the wind towers are shut down as there isn’t a call for energy and there isn’t a way to store it. There is plenty of wind energy in the southwest power quadrant that could be used to provide new opportunities.
The concept of pumped storage was used in the 1960s and 1970s, working with nuclear plants. Times have changed and there is a need to capture wind energy. Livingston said “there are currently 92 pumped storage projects at various stages in the development pipeline of the Federal Energy Regulatory Commission (FERC). Three of these projects have received all permitting authorizations, including the FERC license, but have not yet started construction (but could any day).”
FERC is the nonpartisan oversight body that will handle the licensing of the proposed hydropower project. The final licensing application from MRES and MidAmerican for the proposed reservoir and transmission line is due by the middle of 2025.
When asked, Livingston said drought will have no impact on this system as the water will be pumped to the reservoir and then pumped back out through the raceway. The intake is in a cove that sits back from the Missouri River which is a good place for the powerhouse. The tailrace allows the water to slow down before it gets into the river. The length of the tailrace from the powerhouse to Lake Francis Case, which includes a stilling basin, is currently designed to be 1,900 to 2,000 feet or about .38 miles.
Livingston said this idea was devised and a study permit submitted without any knowledge of potential tax credits. While there is now an emphasis on clean energy tax credits and incentives, the company is not counting on them at this point.
“We do think this project is needed for the region,” Livingston said. “Reliability of energy is our top concern. The polar vortex was a wakeup call. We need to store power so when the wind isn’t blowing, we have those resources to back up those gaps.”
The company has reached out to those in the Yankton and Rosebud Sioux tribes to carefully consider the potential disturbance of cultural artifacts when preparing the sites.
“The reason we are pursuing this project is to provide reliable energy for the region,” Livingston said. “We want to keep the lights on for homes and businesses. People rely on our industry. When renewable sources are available but intermittent, this is a project that has to be done for the entire region. We wouldn’t be pursuing it if the overarching need wasn’t there. It is a needed project.”
Livingston said, “People have a lot of questions and concerns that they are expressing. We appreciate that. It will be a huge change for landowners in the region of the reservoir. It’s hard to give people answers which is why studies will be conducted. We want this to be a good solid project. Their concerns are our concerns as well.”