ISO-NE planning engineer Steven Judd on Wednesday described to the Planning Advisory Committee the key differences between the first and second phases of RTO’s System Operational Analysis and Renewable Energy Integration Study (SOARES).

While last year’s Phase I consisted of the RTO’s traditional economic analysis of scenarios provided by the New England Power Pool, this year’s Phase II focused on operations, requiring input data for wind, solar and electric vehicle charging to analyze intra-hour ramping, regulation and reserve requirements. Phase II will help inform stakeholders about the physical range of resource quantities that could be needed and available given the studied scenarios but will not indicate a requirement going forward, Judd said.

The 2017 study will be released in the first quarter of 2018, he said.

RTO’s Neighbors Seeing Similar Conditions

Michael Henderson, ISO-NE’s director of regional planning and coordination, told the PAC the RTO is seeing the same issues across the Eastern Interconnection, including a surge in distributed energy resources and the retirement of conventional fossil-fuel generators.

“Our other needs we see in New England we do not feel could be better met with additional ties with neighboring regions, and PJM and New York feel the same,” Henderson said.

He noted NERC’s recently published 2017 Long Term Reliability Assessment report, which showed slower demand growth across North America, with conventional generation continuing to retire and new additions of natural gas, wind and solar coming quickly online. (See NERC Report Urges Preserving Coal, Nuke Attributes.)

The changing composition of the resource mix calls for more robust planning approaches to ensure adequate essential reliability services and the fuel supplies. NERC said that 6,200 miles of transmission additions are planned to maintain reliability and meet policy objectives.

New Guidance on Asset Condition Presentations

ISO-NE lead engineer Michael Drzewianowski said the RTO is providing additional guidance to transmission owners regarding when they should present their asset condition needs to the PAC for inclusion on the RTO’s asset condition list.

Drzewianowski noted that a presentation is required if an asset condition need occurs on a pool transmission facility (PTF), and the associated cost of modifications on a single circuit or facility is $5 million or more over a period of five years or less.

For all other asset conditions related to PTF modifications, a presentation is optional. Non-PTF presentation thresholds are determined by each TO.

“It’s tough when each TO has its own idea on when an asset needs to be replaced,” but the planning process does work, Drzewianowski said.

National Grid Updates on NPCC Implementation Plan

Varsha Chatlani, a planning engineer with National Grid, told the PAC that his company estimates it will cost $12.4 million (with a tolerance of +50/-25%) to complete Phase 2 of a project to install dual high-speed protection systems on its PTF circuits. The company in June reported that Phase 1 would cost $1.8 million with a +200/-50% tolerance.

The project was developed in response to a 2015 Northeast Power Coordinating Council plan to install the protection systems on all bulk power system circuits over 10 years.

National Grid first laid out its implementation plan for 45 identified transmission circuits to the PAC in June. The company has started to develop conceptual cost estimates for the other three phases, and it will provide additional updates when more refined estimates are available, Chatlani said.

Eversource Replacing Obsolete Oil Circuit Breakers

Eversource Energy has approximately 1,400 transmission circuit breakers in service and expects to spend nearly $20 million to replace 31 aged and obsolete oil circuit breakers (OCBs), company engineer George Wegh said.

Over the past 10 years, Eversource has been replacing OCBs with sulfur hexafluoride units to upgrade equipment and reduce maintenance costs. These upgrades protect the environment from oil spills and also improve system reliability by reducing equipment failures.

The 31 OCBs remaining on the Eversource 115-kV system are concentrated at three stations: Frost Bridge and Plumtree in Connecticut, and the Agawam station in Western Massachusetts. Three Frost Bridge OCBs are leaking oil.

Eversource recently replaced nine OCBs, not included among the 31 slated for replacement, on an emergency basis.

Further delay in replacing the obsolete OCBs would leave the transmission system vulnerable to age and condition-related reliability risks, and pose safety and maintenance concerns for the remaining circuit breaker fleet, Wegh said.

Eversource 345-kV Structure Replacement Projects

Eversource plans to spend an estimated $231.9 million to replace 1,019 wooden 345-kV structures with steel pole structures, John Case, the company’s director of transmission line engineering, told the PAC.

New England has seen a large increase in the population of pileated woodpeckers, “in the hundreds of percent according to some researchers,” and the birds are damaging old wooden transmission poles, Case said.

Eversource manages approximately 1,100 miles of 345-kV overhead lines in the region, or nearly 50% of such lines in New England, and maintains more than 10,000 345-kV structures. Inspections have revealed significant degradation and decreased load-carrying capacity of wooden 345-kV structures, many of which date from the early 1970s.

Replacing the structures resolves multiple structural and hardware issues, and supports safe and reliable operation, Case said. Hardware, insulators and guy wires are to be replaced along with the structures.

SEMA/RI 2027 Needs Assessment Scope of Work

Jon Breard, ISO-NE associate transmission planning engineer described the scope of work for the upcoming Southeastern Massachusetts and Rhode Island (SEMA/RI) 2027 Needs Assessment. The study aims to evaluate the grid’s reliability performance and identify reliability-based needs in the area for 2027 while also considering reliability over a range of generation patterns and transfer levels, he said.

A 2026 SEMA/RI Solutions Study report completed in March 2017 developed solutions to time-sensitive needs, which will be examined if any exist for the study area. Time-sensitive transmission needs are those that occur within three years of completion of a needs assessment. The RTO plans to issue the report in the second quarter of 2018. (See “Time-Sensitive Tx Needs Determination,” ISO-NE Planning Advisory Committee Briefs: Nov. 16, 2017.)

The short-circuit base case used for the SEMA/RI assessment is based on the expected topology in the 2022 compliance steady state base case. That year was chosen because “no significant project is expected in the 2022-2027 time frame, and the 2022 case was considered acceptable,” Breard said.

— Michael Kuser