Sioux Valley Energy’s history goes back to 1938. Three electric cooperative groups were organized that year; the first was the Sioux Valley Electric Association of Brookings and the other two organizations were East Central South Dakota Electric Association and the Sioux Empire Electric Association. All three had taken preliminary steps towards seeking a loan from the Rural Electric Administration (REA). The three organizations held a joint meeting in December of 1939 and voted to merge together. The new cooperative was named Sioux Valley Empire Electric Association, Inc.

The new Sioux Valley Electric served the area jointly covered by the founding groups, bringing electricity to rural people in Brookings, Lake, Moody, Minnehaha and a portion of Kingsbury County. The cooperative’s office was located in the back room of the Dakota State Bank building in Colman, then moved across the street to a building that earlier had been a hardware store. Efforts began to assure that Colman would be the permanent home of Sioux Valley Electric. The old office facilities soon became overcrowded and a new building was constructed just a mile east of Colman. Dedication ceremonies were held in 1955.

Sioux Valley Electric’s first line-pole went in the ground in eastern Moody County on May 17^th, 1940 and by January 1941 there were a total of 748 members receiving electric service from the cooperative. Line construction continued and by July of 1949, Sioux Valley Electric had 1,350 new members (with 3,800 already receiving service). Sioux Valley Electric was the largest rural electric cooperative in South Dakota, a position it still holds. In 1941, members paid an average of 7.3-cents per kWh. Monthly bills were lower, of course, since the average member was using only 50 kWh a month.

In May of 1951, Humboldt became the first town to sign a franchise agreement with the rural electric cooperative to provide service to the community. Today, Sioux Valley serves Brandon, Chester, Colton, Hartford, Humboldt, Junius, Lyons, Sinai and Valley Springs in South Dakota and Hardwick, Ash Creek, Beaver Creek, Hills, Kenneth, Magnolia and Steen in Minnesota.

Talk of merging Sioux Valley Electric and Southwestern Minnesota Cooperative Electric (SMCE) which served rural areas in Rock and Pipestone counties in Minnesota began in April of 1995. A merger feasibility study was completed and on June 21^st, 1995 the boards of Sioux Valley Electric and SMCE voted unanimously to recommend a merger. Approval of that merger came on September 25^th, 1995 at special membership meetings in Colman and Pipestone, Minnesota. Sioux Valley Electric and Southwestern Minnesota Co-op Electric (SMCE) joined forces to become Sioux Valley-Southwestern Electric Cooperative, Inc. effective January 1^st, 1996 serving 17,000 members.

Sioux Valley-Southwestern Electric Cooperative, Inc. began doing business as “Sioux Valley Energy” in June of 2002. The official name remains Sioux Valley-Southwestern Electric Cooperative, Inc.

The Sioux Valley Energy Operation Round Up program hit its $1-million milestone in December of 2012. Since the year 2000, SVE members have rounded up their electric bill the money rounded up is put into a trust which is then donated to worthy causes and organizations throughout the Cooperative’s service territory.

The Cooperative constructed its first solar array in April of 2015. The 80-panel, 24.8 kw array was energized in May of 2015. SVE employees constructed the entire array.

Sioux Valley Energy was one of 12 participating cooperatives that purchased and acquired a portion of Alliant Energy’s Minnesota service territory in 2015. The 12 co-ops joined together to create the Southern Minnesota Energy Cooperative (SMEC) to serve as the single point of contact for the purchase. Sioux Valley added nearly 900 new members with the acquisition. SMEC received state regulatory approval to acquire Alliant Energy’s Minnesota electric service territory in a verbal decision on Thursday, April 30, 2015, by the Minnesota Public Utility Commission (MPUC).

Also in 2015, a new service center was constructed in Pipestone, Minnesota replacing the old facility which was built by employees in 1945. The old facility was demolished, and a new building, warehouse and pole yard were constructed in its place. An open house for members to tour the new facility was held during the summer of 2015.

Sioux Valley Wireless (SVW) was sold to SpeedConnect and the sale was completed in 2016. Wireless customers had their services transferred from SVW to SpeedConnect in early 2016.

In a 2013 strategic planning session the Sioux Valley Energy Board of Directors made the decision to develop a youth leadership program. The program (EmPOWER) was launched in the fall of 2014. As of 2018 more than 200 high school students have taken part in the program and over $20,000 has been given to those students in the form of scholarships.