SPP's competitive-upgrade transmission design standards reach Revision 4
The 7/14/2026 revision, developed by SPP Staff with Sargent & Lundy, updates the baseline design requirements a respondent's proposal must meet under SPP's Transmission Owner Selection Process, including new 765 kV provisions.
SPP's Minimum Transmission Design Standards for Competitive Upgrades reached Revision 4, dated 7/14/2026 and authored by SPP Staff, which was revised to improve RFP processes and incorporate 765kV information, developed in consultation with Sargent & Lundy.1
Under the standards, SPP publishes a Request for Proposal for each Competitive Upgrade approved for construction by the SPP Board of Directors after January 1, 2015.2
Competitive Upgrades are subject to the Transmission Owner Selection Process set forth in Section III of Attachment Y of the SPP Open Access Transmission Tariff and associated SPP Business Practices.3
Where the RFP and the Minimum Transmission Design Standards conflict, the RFP governs what the respondent uses in its RFP proposal.4
Where the RFP conflicts with the SPP Tariff or Business Practices, the SPP Tariff and Business Practices govern instead of the RFP.5
On the design specifics: The standards list phase-conductor emergency ratings of 4,000 amps for 765 kV lines, 3,000 amps for 345 kV and 500 kV lines, and 1,200 amps for 100-200 kV and 230 kV lines.6
The standards require transmission owners to establish and maintain facility ratings for transmission lines in accordance with the NERC FAC-008 facility ratings methodology and applicable FERC requirements, including FERC Order 881 for ambient-adjusted ratings.7
The standards require lines rated 500 kV or above and longer than 25 miles to include at least one complete transposition cycle, unless documented power-flow, unbalance, and protection studies show a non-transposed design meets SPP Planning Criteria and applicable TO standards.8
The standards require pre-contingency transmission bus voltages to be maintained within 0.95 to 1.05 per-unit of nominal.9
To account for survey and construction tolerances, the standards require a minimum design margin of 2 feet beyond NESC clearances so those clearances are maintained after construction.10
Where a fiber communication path is required, the standards set a minimum of 48 fiber strands in each cable.11
Coverage notes
Gridlight’s notes on what we looked for and did not find; these statements are Gridlight’s own and are not claim-checked against archived sources.
- Unlike Revisions 1-3, the document's own revision history does not name an approving body for Revision 4, only that SPP Staff revised it in consultation with Sargent & Lundy — this piece does not characterize Revision 4 as approved or adopted.
- The document does not state an effective date or whether Revision 4 applies to RFPs already in progress versus only to Competitive Upgrades approved after 7/14/2026 — this piece does not state either.
- No docket number or FERC filing reference appears in the shown text, so this piece does not state whether Revision 4 required or received any FERC action.