A Colorado Public Utilities Commission administrative law judge (ALJ), in a March 1 recommended decision, granted the March 2017 application for a certificate of public convenience and necessity (CPCN) for the construction of the Northern Greeley Area Transmission Plan Project filed by Public Service Company of Colorado (PSCo).
As noted in the filing, the estimated $65m project involves building about 25 miles of new 115/230-kV-capable transmission facilities, originating at the Western Area Power Administration (WAPA) Ault substation northwest of Greeley, Colo., and terminating northeast of Greeley at PSCo’s Cloverly substation. The project also involves building two new substations – Husky and Graham Creek – and modifying one – Cloverly – that would enable PSCo to retire and decommission three existing substations – Public Service Ault, Eaton, and Pleasant Valley.
The ALJ added that PSCo proposes to build the Husky substation to replace the Public Service Ault 44-kV substation. The Husky substation – which would include 230-kV and 115-kV transmission equipment – would also be built to accommodate a 115/12.47-kV, 50 MVA distribution transformer to allow for the existing distribution lines in the area to be interconnected at Husky and served by the 115-kV system. Adequate spaced would be maintained for the future installation of two additional distribution transformers, the ALJ added, noting that a new 230-kV termination would be installed at WAPA’s Ault substation.
PSCo also proposes to build the new Graham Creek substation to replace the existing Eaton 44-kV substation, which would be decommissioned. The proposed substation would include 115-kV transmission equipment, including a 115/12.27-kV, 50 MVA distribution transformer and line termination equipment, and it would be built with sufficient space for future installation of two additional transformers, the ALJ added. The Graham Creek substation would be built to accommodate distribution transformers to allow for the existing distribution lines in the area to be interconnected at Graham Creek and served by the 115-kV system.
Noting that PSCo also proposes modifications to the existing Cloverly substation, the ALJ said that PSCo built that substation in 2016 adjacent to the existing Pleasant Valley substation to interconnect a new customer retail load that was too large to be served by the 44-kV system from Pleasant Valley. The Cloverly substation would now be expanded in order to terminate a new line from Graham Creek and to allow for future load interconnection requests, the ALJ said. The Cloverly expansion would also accommodate new distribution transformers to allow for the existing distribution lines that are presently connected at Pleasant Valley to be interconnected at Cloverly and served by the 115-kV system. The ALJ added that PSCo would also modify Cloverly to leave room for the future installation of two additional transformers. Once the Northern Greeley Project is completed, the Cloverly substation would replace the Pleasant Valley substation, which would be decommissioned, the ALJ said.
Discussing the transmission line portion of the project, the ALJ noted that the approximately seven-mile, double-circuit, 230-kV-capable Ault-Husky 230-kV line would be built from the WAPA Ault substation to a new Public Service Husky substation, which is expected to be located near the existing Public Service 44-kV Ault substation. Only one circuit would initially be installed and operated at 230 kV.
The ALJ added that the Husky-Graham Creek 115-kV line would be about seven miles and built double-circuit, 230-kV-capable; PSCo proposes to install only one circuit in this project to be operated at 115 kV.
The Graham Creek-Cloverly 115-kV line would be about 11 miles long and according to PSCo, only one circuit would initially be installed and operated at 115 kV, the ALJ said. Eight miles of that new line would be built double circuit, 230-kV-capable, the ALJ said, noting that the remaining three miles are already built to be 115-kV-capable.
The ALJ noted that according to PSCo, the project would satisfy a current need to increase the reliability and load serving capacity of the existing 44-kV transmission system in and around Greeley, as well as address the need for additional future capacity for expected growth in a region where there is a substantial possibility that the load will increase beyond the current 44-kV system’s capacity as early as 2018.
The ALJ said that PSCo has provided substantial evidence of the present and future need for the proposed project and that existing facilities are not reasonably adequate and available to meet that need.
In addition, the ALJ noted that PSCo has established that the project would allow PSCo to coordinate with other transmission plans and thereby expand PSCo’s backbone transmission system from the Greeley area to Denver. The project would allow PSCo to coordinate with Tri-State Generation and Transmission Association’s Southwest Weld Expansion Project (SWEP) and PSCo’s Southern Greeley Project, the ALJ said.
As noted in the filing, the SWEP involves building a 115/230-kV transmission system roughly between Ft. Lupton and Kersey in Colorado, while PSCo’s preliminary Southern Greeley Area Plan project involves building 230-kV transmission lines between the Weld and Rosedale substations as well as the Rosedale and Milton substations.
The ALJ noted that PSCo plans to eventually provide a 230-kV path from Ault to the Denver metro area, and the project is a key component of that plan.
The ALJ also said that the fact that the project’s $65m projected cost is a “high-level scoping estimate” that could vary by plus or minus 30% is somewhat concerning. However, the OCC has reviewed, and conducted discovery on, those costs, and is satisfied that they are reasonable under the circumstances, the ALJ said. For that reason – and because PSCo has complied with a certain rule by itemizing the costs based on land costs, substation costs, and transmission line costs – the ALJ concluded that PSCo has carried its burden on this question at this stage. However, due to the fact that the identified cost is a “high-level scoping estimate,” no amount of expenditures is deemed prudent at this time, the ALJ said.
Among other things, the ALJ said that the expected magnetic field values and audible noise values from the proposed transmission lines meet the conditions of certain commission rules and are therefore considered reasonable and neet not be mitigated.
The grant of the application and the CPCN is contingent upon PSCo providing to the commission the information relevant to determining whether PSCo has complied with the statutes and rules concerning the reasonableness of the magnetic fields and noise caused by the new and modified substations.
If no exceptions are filed within 20 days after service or within any extended period of time authorized, or unless the decision is stayed by the commission upon its own motion, then the recommended decision is to become the decision of the commission, the ALJ said.