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PRESS RELEASE | NYISO to Host Forum on Transmission Congestion Study

April 23, 2018

Rensselaer, N.Y. | On Tuesday, May 1 the New York Independent System Operator (NYISO) will host a forum to present the results of its 2017 Congestion Assessment and Resource Integration Study (CARIS). The forum will be held from 1:30 to 3:30 in the Peter A. A. Berle Conference Center at the NYISO’s corporate headquarters in Rensselaer.

The CARIS report presents economic analysis of transmission congestion on the New York state bulk power system and the potential costs and benefits of relieving transmission congestion. Approved by the NYISO Board of Directors, the study was developed as part of the NYISO’s comprehensive planning process with defined assumptions and procedures and with extensive stakeholder input. The report provides information to market participants, policy makers, and other interested parties for their consideration of projects that may address system congestion identified in the study.

Identifying Congestion on the System

Transmission congestion results from physical limits on how much power the New York electric grid can reliably transfer. Congestion adds to the costs of electricity by limiting the ability of lower-cost power to be transmitted to consumers. Solutions to congestion include building or upgrading transmission lines, building less expensive power generation next to the load or employing measures to reduce demand for electricity in the congested area.

The 2017 CARIS identified the most congested parts of the New York state bulk power system based upon historic data (2012-2016) as well as estimates of future congestion (2017-2026). Those areas include all or parts of the high-voltage transmission around the Edic-Marcy substation in Central New York (Central East-Edic-Marcy), the path from Oneida County through the Capital Region (Central East) and south to the Lower Hudson Valley (Central East - New Scotland – Pleasant Valley).

As a result of local transmission upgrades and the NYISO’s selection of a project to address the Western New York Public Policy Transmission Need, the 230-kilovolt system in Western New York identified in prior CARIS reports is no longer one of the most congested areas.


Next Phase

During the next phase of the CARIS process, developers are invited to propose specific transmission projects to address congestion on the New York bulk power system. The NYISO will perform a benefit/cost analysis for each specific proposed transmission project to assess eligibility for regulated cost recovery.  Under the NYISO’s tariff, this analysis examines only statewide production cost savings and does not include other potential public policy and economic benefits.

The CARIS process analyzed generic transmission, generation, energy efficiency and demand response solutions in these regions that could ultimately yield savings for power consumers. Project costs and benefits are compared to assess the cost-effectiveness of the generic solutions in resolving the congestion. Unlike similar studies, such as those being conducted in the New York State Public Service Commission’s AC Transmission proceeding, the CARIS process limits the analysis of project benefits to a reduction in statewide system production costs. While it does report other benefits such as reductions in emissions, capacity market payments and consumer energy payments, these are not reflected in the benefit-to-cost ratios calculated in the CARIS report.

The CARIS process is separate and distinct from the NYISO’s Public Policy Transmission Planning Process.  In the New York State Public Service Commission’s AC Transmission proceeding, the Commission has identified a public policy need to increase transfer capability between upstate and downstate for a variety of reasons, including but not limited to improving the flow of renewable energy to Southeastern New York, strengthening system reliability, and reducing capacity and congestion costs.  The NYISO is currently evaluating viable and sufficient transmission solutions to identify the more efficient or cost-effective solutions.

The full CARIS report and appendices are available for download from the NYISO website,

The CARIS public forum is free of charge, however, space is limited. Registration must be received by 12:00 on Monday, April 30 to participate in person. The proceedings also will be available via the Web. Interested attendees can register online by clicking the “RSVP here” link on the NYISO Committee Calendar.

We are an independent, not-for-profit corporation responsible for operating the state’s bulk electricity grid, administering New York’s competitive wholesale electricity markets, conducting comprehensive long-term planning for the state’s electric power system, and advancing the technological infrastructure of the electric system serving the Empire State.