Explore how developers identify and screen potential sites by evaluating transmission capacity, congestion, queue competition, curtailment risk and other factors that influence interconnection viability.
Identifying a viable interconnection site is typically a multi-stage screening and validation process. Developers evaluate transmission access, available capacity, congestion exposure, queue competition, and long-term economic performance before committing capital to land acquisition, interconnection deposits, or detailed engineering studies. This can be accomplished through early-grid screening platforms.
A site may appear attractive based on available capacity alone, but viability ultimately depends on how the project performs under real system conditions and whether it can progress through the interconnection process without excessive upgrade costs, curtailment exposure, or schedule risk.
Most developers follow a progressive filtering process that narrows a large universe of candidate locations into a smaller set of technically and economically viable opportunities.
Development often begins at the market level, where teams evaluate regions based on transmission expansion, power demand growth, pricing dynamics, and renewable buildout activity. From there, screening typically narrows toward substations, transmission lines, and candidate Points of Interconnection (POIs) capable of supporting generation or large load.
As projects advance, developers increasingly shift from broad screening into more detailed engineering and economic analysis to validate whether a project can realistically survive the interconnection process and operate competitively over time.
Early-stage screening usually begins with identifying apparent available transmission capacity. Developers review ISO queue data, planning models, transmission maps, and infrastructure proximity to determine where interconnection opportunities may exist.
However, available capacity is only one factor in determining project viability. The goal is not simply to find capacity, but to understand the level of interconnection risk a project presents and whether that risk aligns with a developer's strategy. A substation may appear capable of supporting additional injection while still experiencing congestion, thermal overloads, deliverability limitations, or significant upgrade exposure under modeled operating conditions and contingency scenarios.
As interconnection queues become more saturated, developers increasingly rely on engineering-grade power-flow analysis rather than static GIS overlays or simplified capacity maps alone to quantify project risk, understand how a project interacts with the broader transmission system, and make more informed siting decisions.
After identifying candidate locations, developers evaluate how power from a project flows across the transmission network and whether nearby constraints could limit deliverability.
This stage often includes evaluating congestion exposure, competing queued resources, and how projects interact with constrained transmission facilities under different operating conditions. In cluster study environments, project outcomes are increasingly influenced by the behavior of neighboring projects, shared upgrades, and evolving system conditions.
Developers therefore evaluate not only whether capacity exists, but how competitive a project may be relative to other queued resources connected to the same constrained system.
Shift factor (aka DFAX) analysis is commonly used during this stage to evaluate how strongly a project contributes to congestion on monitored transmission elements and how it compares to competing resources.
Curtailment analysis helps developers estimate the likelihood that a project will be unable to fully deliver energy due to congestion or economic dispatch conditions.
This evaluation often includes production cost simulations, forecast locational marginal pricing (LMP), congestion trends, and long-term transmission assumptions. A project may successfully interconnect while still experiencing poor long-term economics if curtailment exposure is excessive.
As a result, many developers now incorporate curtailment analysis much earlier in the development process to allocate resources to projects most likely to succeed both in interconnection and market participation.
Related resource: Large Load Interconnection White Paper
Once a project survives early-stage screening, developers typically perform deeper engineering validation before formally entering the interconnection queue.
This phase may include detailed power-flow analysis, contingency evaluation, short-circuit analysis, preliminary facility design, and interconnection application support. The objective is to confirm that earlier screening assumptions remain technically defensible under utility or ISO study conditions.
Engineering validation is increasingly important as queues become more competitive and readiness requirements continue to rise. Projects that advance into formal study with unrealistic assumptions often encounter redesign requirements, study delays, forfeited deposits, or unexpected upgrade costs later in the process.
Understand the factors beyond available capacity that determine whether a project can successfully interconnect, including deliverability, congestion, queue competition and changing grid conditions.
The short answer is no. Available transmission capacity is an important starting point, but it does not determine whether a project will successfully interconnect or operate economically. Developers often begin by reviewing capacity data because it helps narrow the universe of potential sites, but capacity represents only one piece of a much larger technical and commercial evaluation.
As projects move closer to interconnection, other factors begin to influence the outcome. Transmission constraints, congestion, deliverability limitations, upgrade requirements, and competing projects already in the queue can all affect whether a project ultimately succeeds. Two substations with similar available capacity may produce very different study results depending on how power flows through the surrounding network and how local system conditions evolve over time.
The goal of early-stage screening is not simply to find available capacity. It is to understand the level of interconnection risk associated with a location before significant development capital is committed. Developers increasingly combine capacity analysis with engineering-grade power flow modeling, congestion analysis, and queue intelligence to determine which opportunities justify additional investment.