Interregional Transfer Capability Study (ITCS) Final Report: Strengthening Reliability Through the Energy Transformation
North American Electric Reliability Corporation (NERC)01 Nov 2024all-rights-reservedRead the original
No copyright notice or terms found in the document. NERC is a private non-profit certified as the Electric Reliability Organization, not a federal agency, so public-domain status does not apply even though Congress mandated the study. Treat as all rights reserved.
NERC's congressionally mandated study is the first assessment of transfer capability between US transmission planning regions carried out under a common set of assumptions. Its central conclusion is that an additional 35 GW of interregional transfer capability would strengthen energy adequacy under extreme conditions. The study stresses that transfer capability cannot be reduced to a single figure: it varies by season and system condition, and total import capability ranges from as little as 1 percent to as much as 92 percent of peak load depending on the region. Modelling across twelve historical weather years found the potential for energy deficiency in every year examined and in eleven different planning regions, with the largest shortfall approaching 19 GW in ERCOT. NERC cautions that a uniform minimum transfer requirement applied to all regions could be inefficient, framing its recommended additions as directional guidance rather than construction directives.
Quotation
“"An additional 35 GW of transfer capability is recommended across the United States as a vehicle to strengthen energy adequacy under extreme conditions."”
North American Electric Reliability Corporation (NERC) · all-rights-reserved · Read the original
All rights reserved. Only this short quotation is reproduced here.
The MyGreenSuit briefing
Commentary by MyGreenSuit, not the words of North American Electric Reliability Corporation (NERC).
This is a 2024 document, so treat it as the baseline rather than the news. It matters because its 35 GW figure is the anchor every later transmission argument is tied to, including the 2026 DOE draft.
The finding that gets quoted least and explains most: interregional transfer capability ranges from 1 percent to 92 percent of peak load depending on which region you are standing in. There is no such thing as "the US grid" in any operational sense, and the variation between regions is nearly two orders of magnitude.
NERC also do something worth respecting. Having been asked by Congress for a number, they explicitly warn against turning it into a uniform national mandate, on the grounds that regions differ enough that a flat requirement would buy expensive capability where nobody needs it. A body declining to convert its own finding into a rule is rarer than it should be, and it is the right instinct — the study tells you where the gaps are, and the regions living with them are better placed to decide what closes them.
That caution rarely survives the trip into advocacy material. Keep it in view whenever someone quotes the 35 GW without the sentence that follows it.