Con Edison Large Load Planning Updates Transmission Planning Criteria, NYISO TPAS, July 7, 2026
Con Edison presented informational updates to its transmission planning criteria, Specification TP-7100, that bring large loads and end-user facilities under design principles previously written only for new generation and transmission. The revisions insert “large loads/end-user facilities” directly into those principles, meaning a data center seeking to interconnect faces the same substation diversity, breaker-failure, and bus-section requirements as a generator. Con Edison is not obligated to supply or absorb reactive power for these facilities, which must maintain reactive neutrality at the point of interconnection.
Con Edison Large Load Planning Principles
Two new principles come with the update. Large loads must incorporate under-frequency load shedding capability conforming to Con Edison’s program thresholds and shedding amounts, operational as of the commercial operation date. And substation equipment overloaded in pre- or post-contingency conditions must be replaced with higher-rated equipment. Con Edison characterized the package as providing clarity to principles it already had.
On the 2026 RNA, NYISO re-presented its candidate scenarios, and reopened the comment window. Written feedback had been requested by July 2; NYISO asked for further comments by July 10, with the final scenario list still targeted for late July. The assumptions were unchanged: aging generation at risk in 2036 ranging from 1,213 to 3,036 MW, a cost-allocated project pool of 10,900 MW against a 6,300 MW base case, and large-load demand ranging from 1,211 to 4,113 MW by 2036.
Updated Load Forecast Uncertainty Models
Updated Load Forecast Uncertainty models were also presented, revised after summer 2025 temperatures ran well above normal and the 2025-26 winter came in below normal. These multipliers capture the risk of higher load driven by extreme weather, and NYISO recommends applying the new values in the 2026 RNA and the 2027-2028 Installed Reserve Margin study. Recommended 2027 bin-one multipliers are approximately 110 percent in Zone J and 116 percent in Zone K, with the NYCA winter model at roughly 110 percent. The winter figures are not a single fixed value but a year-by-year curve, on the premise that winter load grows more weather-sensitive as electrification advances. That curve was refreshed using 2026 Gold Book growth rates for EV charging, heating electrification, and large loads.
NYISO’s Points of Interconnection Analysis Heatmap
NYISO’s Points of Interconnection Analysis Heatmap is now available, giving prospective interconnection customers a preliminary view of potential MW capacity at points of interconnection across the state, filterable by kV level and with an optional overlay of current queue projects. NYISO is explicit that the results are informational, that the tool does not account for voltage or stability constraints, and that it does not replace the interconnection studies, where additional constraints may surface.
Date Milestone
July 10 Further written scenario feedback requested
Late July Final RNA scenario list posted
Planning a Large Load or Data Center Interconnection?
As utilities and system operators continue updating planning requirements to accommodate growing demand from data centers, electrification, and other large loads, understanding evolving transmission and interconnection criteria is critical. Zero-Emission Grid (ZEG) helps developers, utilities, and large energy users navigate interconnection requirements, transmission planning, grid impact studies, and power system analyses to reduce risk and support informed project decisions. Contact our team to learn how we can support your next project.
