While the state does not set transmission standards, an important role remains for the state commissions to advise on their views as to the appropriate local transmission planning standards, according to Central Maine Power (CMP).
“Commission guidance as to its views on local planning standards could be helpful in avoiding unnecessary and potentially costly disputes and assisting CMP (and the other Maine utilities) in its identifying and applying its good utility practices,” CMP said in its Nov. 8 brief related to the Maine Public Utilities Commission’s (PUC) investigation into Maine’s electric utilities transmission planning standards and criteria (Docket No. 2011-00494).
While state commissions lack authority to set enforceable transmission planning standards, they could potentially use their siting authority to block or attempt to block approaches to resolving reliability concerns that involve siting new facilities. Therefore, at a minimum, CMP added, it is better for all concerned that the state commission’s views on local planning issues be clear, to facilitate avoiding conflict when possible.
“CMP therefore encourages this commission to identify the transmission planning standards [under] which the commission will sign off on future upgrades of transmission facilities (assuming such upgrades are deemed appropriate under federal standards),” CMP said.
The PUC chairman said the PUC could do so through a “safe harbor” whereby the utilities would know that if they planned their non-bulk electric system (BES) transmission facilities in accordance with the safe harbor planning standards noted in the docket, the commission would not later challenge the transmission upgrade on the grounds that the planning standards used to justify the need for the upgrade were inappropriate in any way.
However, CMP added, should a utility seek to justify a transmission upgrade by reference to a more stringent planning standard, then that utility would have to make some sort of cost/benefit analysis supporting why the more robust upgrade is appropriate under the circumstances, including that it provides increased reliability and/or longevity or other benefits, such as increased support for renewable generation development for a modest additional cost.
Knowing definitely the commission’s position regarding the remaining planning standards in dispute would help streamline future certificate of public convenience and necessity (CPCN) proceedings such that they may be completed within the six-month statutory period by reducing, if not eliminating, the fights over the appropriate planning standards.
Such regulatory certainty, CMP added, would also encourage the utilities to act outside the safe harbor only when necessary in their view to ensure reliability of the interconnected grid.
Among other things, CMP noted that much common ground has been confirmed so far in the PUC’s investigation. PUC staff and the company agree, for instance, that it is appropriate for CMP to use a 90/10 peak load forecast for purposes of setting a reasonably stressed base case for planning its BES/primary transmission feeder (PTF) and local transmission systems.
A handful of areas of dispute remain, including CMP’s use of an 85% of 90/10 peak load forecast for planned maintenance testing. Staff believes this is an “overly stressed case” and instead continues to recommend that planned maintenance testing be done at 75% or 85% of CMP’s 50/50 peak load forecast.
“CMP respectfully submits that conducting planned maintenance testing (and mitigating any violations found as [a] a result) at either of these load levels will not fulfill the propose of planned maintenance testing, namely to design the sub-transmission system to remain reliable during an appropriate window of time when facilities are removed from service for planned maintenance,” the company added.
CMP is working on the proposed $1.4bn, 440-mile, 345-kV Maine Power Reliability Program, which will begin in Eliot and end in Orrington, Maine, according to TransmissionHub data.
The Maine Public Advocate also filed a brief on Nov. 8, telling the PUC that CMP should not be allowed to upgrade its local system based upon violations revealed through the more rigorous system planning requirements it has adopted in response to FERC and NERC proposed expansions of system planning.
Electric transmission system planning has been in a state of change due to, for instance, FERC orders requiring NERC to address FERC’s concerns regarding the BES definition and the inconsistent application of the definition among the various reliability regions.
As a result of the NERC and FERC expansions of system planning, CMP has implemented a fully integrated system model for its planning and testing that reflects the newly defined BES facilities, as well as the local transmission system facilities connected to these BES facilities. The effect of this change, the public advocate added, is that testing on the 115-kV system, in some circumstances, is more rigorous than the prior N-1-1 testing and may reveal low impact violations on the 115-kV facilities as well as planning violations on the local transmission facilities.
NERC’s focus is on looking for contingency situations that threaten the electric grid’s integrity, but there is the potential for finding low impact violations on the 115-kV facilities that have existed for years without really having the potential to affect reliability on the BES.
The public advocate also said that CMP’s current local transmission system, the product of the last 20 or 30 years of local system planning, is reliable.
Among other things, the public advocate said “there is no need to spend more ratepayer money to create a ‘more’ reliable system,” adding that CMP has not shown a need to address violations that would not be revealed by the time-tested N-1/single contingency transmission system planning that the company employs to test its local system.
“[W]e urge the commission not to allow any related upgrades to be made,” the public advocate said.
CMP is a subsidiary of Iberdrola USA, which is a subsidiary of Iberdrola S.A.