Colorado PUC approves new substation, 230-kV line by Xcel’s PSCo

The Colorado Public Utilities Commission (PUC) on Jan. 20 approved the application of Public Service Company of Colorado (PSCo) to add a new substation and a 250-foot transmission line extension in Arvada, Colo., to meet load growth and improve reliability in the area.

The item was on the agenda for the PUC’s Jan. 20 meeting, and an order is expected to be available in a few days, a PUC spokesperson told TransmissionHub Jan. 20.

The addition of the Moon Gulch substation and the short, 230-kV line, along with a new distribution transformer and feeders, is expected to cost $13.5m. Construction is expected to start in March 2017, and the project has a planned in-service date of June 1, 2018, according to PSCo.

PSCo, a subsidiary of Xcel Energy (NYSE:XEL), filed its application for a certificate of public convenience and necessity on Nov. 25, 2015, telling the PUC that the project would cost-effectively meet short-term and long-term load growth driven by two large housing developments and address reliability concerns in the area. The project is designed to provide back-up and load transfer services for the nearby Simms, Ralston and Quaker substations and to provide additional solar power hosting capacity in the area, PSCo said in its application.

That latter element raised concern from the Energy Freedom Coalition of America (EFCA), an advocacy group that promotes the use of distributed energy resources, which intervened in the case and said if the project is mainly needed to address increased solar power penetration in the area, lower-cost alternatives should be pursued by the utility.

PSCo responded to the comments on Jan. 8, clarifying that the project is driven by load growth and housing additions in the area, and that the additional solar hosting capacity is simply an added benefit.

EFCA then withdrew its motion to intervene on Jan. 15, satisfied with the utility’s answer, EFCA told the PUC.

The new Moon Gulch substation and related equipment are slated for the Leyden area of Arvada, bounded by 96th Ave. to the north, 72nd Ave., to the south, Highway 93 to the west and Indiana St., to the east, according to the PSCo application. The project is planned to interconnect with PSCo’s nearby Plains End–Valmont 230-kV transmission line, PSCo said in the application.

Among the options considered as alternatives were additions to nearby substations and constructing similar facilities on PSCo-owned land, PSCo said. But after applying criteria such as sensitive view corridors, distance between a planned site and existing transmission lines, distance between a planned site and load centers, geologic hazards and compatibility to adjacent land uses “we determined that the Moon Gulch project, as proposed, meets our needs in the most cost-effective and efficient manner,” PSCo said.

The substation will include a single distribution transformer and switchgear for five distribution lines, but it will be designed to accommodate up to three transformers and a total of 15 distribution lines without requiring an expansion of the project’s footprint, the utility told the PUC.

PSCo said it has negotiated rights to 4.3 acres of land for the substation, with perhaps an additional acre needed for storm water runoff management.