National Grid seeks declaratory ruling in New York on reporting requirements for overhead transmission lines

Niagara Mohawk d/b/a National Grid USA is requesting a declaratory ruling by New York state regulators that would relieve the company of preparing “Part 102 reports” for the large number of transmission line projects that are undergoing typical maintenance intended principally to restore the lines to their original design condition and function and/or mitigate substandard clearances.

A company spokesperson told TransmissionHub on Sept. 6 that Part 102 of the state Public Service Commission’s (PSC) regulations establishes reporting requirements for any proposal to build overhead “transmission facilities,” defined as “[i]tems of electric plant not subject to the commission’s jurisdiction under Article VII of the Public Service Law used to convey electric energy at 65 kV or higher voltage for distances one mile or longer including: towers, poles and appurtenant fixtures; wire, cable and devices; conduit, tunnel, conductors and devices.”

In its Sept. 5 petition, National Grid said the principal question underlying the petition is what constitutes the upgrading or rebuilding of a transmission line under Section 102.2(a)(2).

According to the spokesperson, that section notes that no Part 102 Report is required to be filed with the PSC for upgrading or rebuilding transmission facilities on existing right-of-way (ROW) provided that all five of the specified conditions under the section are met. Those conditions are: no additional ROWs are required; there is no increase in the number of structures on the ROW; the resulting structures do not carry more than two circuits; no substantial modification will be made to existing vegetative cover on the ROW; and the height of a new tower does not exceed the height of a replaced tower by more than 10 feet.

National Grid said in the filing that its specific request is for a ruling from the PSC declaring that neither upgrading nor rebuilding occurs for purposes of that provision unless either or both of the following actions are taken: the line is reconductored with a larger diameter conductor for a contiguous linear ROW distance of one mile or more, or if the line’s operating voltage is increased.

The driver of this question is a considerable quantity of maintenance work National Grid plans to do in the near future on non-Article VII transmission lines intended only to restore those lines to their original design condition and/or function.

A primary reason for National Grid’s intended work on many of the existing non-Article VII lines is the company’s need to assure that its electric transmission lines protect public safety and provide a reliable supply of electricity.

An important National Grid maintenance program is its conductor clearance assessment program, which is needed to assure that the heights of transmission conductors above the ground conform to the PSC’s electric safety standards.

Another important National Grid maintenance program is the replacement of deteriorated transmission line assets such as supporting structures, conductors and shield wires.

National Grid added that through those and other initiatives, the company has identified numerous non-Article VII transmission lines that require modifications, which fall into the following categories of interest, with multiple examples of one or more of those categories of modifications intended for each transmission line targeted:

  • Replacing a single existing structure with a single new structure in proximity to the existing structure. A replacement structure can be either a replacement structure that is greater than 10 feet higher than the structure being replaced or a replacement structure that is 10 feet higher or less than the structure being replaced.
  • Adding to the ROW of a transmission line one or more structures that are not replacement structures.
  • Adjusting the clearance to ground or to other obstructions of existing conductors by installing one or more replacement or new structures.
  • Replacing existing shield wire(s) with new shield wire(s).
  • Replacing existing conductors with new conductors of the same or smaller diameter.

National Grid requested that the PSC assume for all purposes related to the petition that each of the lines whose intended modifications are the subject of the petition is an overhead line that meets the definition of “transmission facilities” in Part 102; and the line, for instance, will require no additional ROW, the resulting structures will carry no more than two circuits and the work will not involve substantial modification to existing vegetative cover on the ROW.

“Thus only transmission lines that would receive one or more new structures, greater than 10-foot-higher replacement structures, new shield wire, and/or new conductor are the subject of this petition,” the company said.

Given the language of Section 102.2(a)(2), only when such work constitutes the “upgrading” or “rebuilding” of the line does it need a report under Part 102. “National Grid urges the commission to explicitly determine that neither ‘upgrading’ or ‘rebuilding’ takes places unless (A) the line is reconductored with a larger diameter conductor for a contiguous linear ROW distance of one mile or more, or (B) the line’s operating voltage is increased,” the company said.

With such a determination, any work that does not meet either of those two descriptions would be considered line maintenance and not within the scope of Section 102.2(a)(2) – and therefore, outside the scope of Part 102 altogether.

Two further conclusions follow logically from such a determination, the company added. First is the conclusion that a Part 102 report would not be required for a project affecting any distance of ROW that is proposed to install new structures and/or greater than 10-foot-higher replacement structures unless the work described in clause A or B above also takes place, the company said.

Second, it follows that if neither clause A nor B is met that a Part 102 report would not be required for a project that replaces existing shield wire with new shield wire or replaces existing conductor with new conductor of the same or smaller diameter.

This approach would affirmatively bring the one-mile threshold included in the definition of “transmission facilities” into the determination of whether a reconductoring project with a larger diameter conductor constitutes the “upgrading” or “rebuilding” of the line, National Grid added. It would also recognize that, on the other hand, when a change modifies the line’s operating voltage, it changes the character and function of the entire transmission circuit and thus PSC review under Part 102 would be warranted.

“For these reasons, the interpretation of Part 102 advocated by National Grid would be consistent with the underlying policy objectives of that regulatory regime: to enable the commission to examine a proposed overhead transmission line (or a sufficient magnitude of modifications thereto) in order to evaluate whether to require that the line be undergrounded,” National Grid added.

No purpose is served by a Part 102 review of an existing transmission line proposed to be modified in a way that neither affects line operating voltage nor replaces conductor with a larger diameter conductor for a contiguous linear ROW distance of one mile or more.

National Grid also said that absent such levels of impact, it is extremely unlikely that, if a Part 102 report were filed, the PSC would decide to require undergrounding. Furthermore, it is even more difficult to anticipate what exactly such an undergrounding mandate would entail, the company said.

National Grid is a subsidiary of National Grid plc.

About Corina Rivera-Linares 3105 Articles
Corina Rivera-Linares, chief editor for TransmissionHub, has covered the U.S. power industry for the past 15 years. Before joining TransmissionHub, Corina covered renewable energy and environmental issues, as well as transmission, generation, regulation, legislation and ISO/RTO matters at SNL Financial. She has also covered such topics as health, politics, and education for weekly newspapers and national magazines. She can be reached at