Southern Maryland Reliability Project Completed
Southern Maryland Electric Cooperative completed its Southern Maryland Reliability Project on Nov. 3 when it energized the under-river portion of the 230,000-volt line that creates a transmission loop through the cooperative’s service area.
According to Ken Capps, SMECO’s Senior Vice President of Engineering and Operations and Chief Operating Officer, “The entire loop, which has been built in sections, has been a part of SMECO’s vision since the early 1970s. In 1973, SMECO started the process of applying for the necessary permits, and the first section of the 230-kilovolt (kV) line from Ryceville to Lexington Park was energized in 1990. As the population and the demand for electricity increased, the necessity for a complete 230-kV loop increased.”
SMECO’s announcement for plans to upgrade the line to include 230,000-volt circuits officially began in 2008 at a meeting of the Calvert County commissioners on Apr. 15 and St. Mary’s County commissioners on April 22. After holding a series of open houses for the public and receiving customer-member comments about the project, the cooperative applied to the Maryland Public Service Commission for a Certificate of Public Convenience and Necessity (CPCN) on Nov. 21, 2008, and the Commission granted the CPCN on Sept. 9, 2009.
The culmination of the project was crossing under the southern portion of the Patuxent River from the Navy Recreation Center in Solomons to Town Creek in St. Mary’s County. During October, construction was completed and the line was tested before it was energized and put into service on Nov. 3.
According to SMECO, although the project greatly enhances reliability for all of the cooperative’s customers, it is vitally important to Calvert County and lower St. Mary’s County, including Naval Air Station Patuxent River. SMECO President and CEO Austin J. Slater, Jr., said, “Electric utilities are obligated to maintain the highest standard of reliable service and provide the most up-to-date technology to improve economic and operational efficiency. By completing this 230,000-volt loop through our service area, customer-members are assured of improved reliability.”
Mr. Capps highlighted the crowning achievement of the project: “We faced considerable challenges associated with engineering the river crossing. A year ago, we used a horizontal directional drilling technique to bore under the riverbed, and then pulled two bundles of five fusible PVC pipes through the bored holes. This was a first for the industry; no previous installations using fusible PVC come close to the length and complexity of this project. In October 2014, we completed the under-river crossing when we pulled cable through the conduit.”
SMECO’s other construction highlights include: five miles of PVC conduit and 6.9 miles of cable were used to complete the river crossing; 19,543 cubic yards of concrete were used for the foundations of 291 steel poles, replacing 430 poles used for the previous 69-kV line; 5 miles of roads were graded along the right-of-way and for construction access; and 15 helicopter flights were used to install 181 of the 197 miles of conductor for 28 miles of overhead spans. Additionally, SMECO has received accolades from environmental and permitting agencies that hold this project up as an excellent example in completing a project the right way: using existing right-of-way and working with customers along the route to minimize the line’s impact.
“Our previous peak demand record was set on Jan. 17, 2009, at 848.8 megawatts (MW). In January, when the polar vortex brought us unusually cold weather, we surpassed that peak on six different days, and we set a new peak of 941.3 MW. We expect this new line to provide enough capacity to see us through the next 50 years,” Mr. Slater said. He concluded, “I am immensely proud of the creative and gifted engineering, project management, and skilled execution exercised by our team in delivering this critical component of our electric system. And I am delighted that it was completed on time and under budget.”
