Understanding Large Load Interconnection

The document outlines the six-step interconnection process for large loads (over 20 MW), detailing the progression from preliminary inquiry to the execution of an interconnection agreement. It distinguishes between customer interconnection facilities, which are typically paid for by the customer, and network upgrades, which ensure broader grid reliability and are often allocated across a service territory. The guide also describes the roles of FERC and state PUCs in cost recovery and allocation.

• Large loads, defined as those exceeding approximately 20 megawatts (MW), such as data centers, require direct connection to the transmission system rather than the distribution system to avoid overloading capabilities or creating inefficiencies.
• The load interconnection process consists of six conceptual steps: preliminary inquiry and scoping, the formal interconnection request, a feasibility study, a system impact study (SIS), a facilities study, and the final interconnection agreement.
• The System Impact Study (SIS) is identified as the most critical phase of the process because it determines the necessary infrastructure and assigns preliminary cost responsibility.
• Interconnection triggers two distinct types of upgrades: customer interconnection facilities, which provide the direct link to the point of interconnection (POI) and are typically paid for by the customer, and network upgrades, which ensure broader grid reliability.
• Network upgrades are identified by simulating power flows under various scenarios (such as peak summer and winter) to check for violations of NERC standards; these costs are typically allocated across the transmission provider's service territory using FERC methodologies.
• Cost recovery for transmission involves a multi-tiered regulatory process where FERC approves regional cost allocation and annual recovery for transmission owners, while state Public Utility Commissions (PUCs) approve how local utilities allocate those costs to retail customer classes.
• The timeline for the full interconnection process is highly variable, ranging from several months to several years, making it a primary determinant of cost and schedule for large load projects.

APA

RMI (2026). Understanding Large Load Interconnection. https://rmi.org/resources/understanding-large-load-interconnection/

Chicago

RMI. Understanding Large Load Interconnection. 2026. https://rmi.org/resources/understanding-large-load-interconnection/.

Wikipedia

{{cite report |author=RMI |title=Understanding Large Load Interconnection |date=14 April 2026 |url=https://rmi.org/resources/understanding-large-load-interconnection/ |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{rmi2026understanding, author = {{RMI}}, title = {{Understanding Large Load Interconnection}}, institution = {RMI}, year = {2026}, month = apr, url = {https://rmi.org/resources/understanding-large-load-interconnection/}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }