ERCOT has released new guidance on complying with the Public Utility Regulatory Act (PURA) Section 39.169, a reform introduced under Senate Bill 6, requiring ERCOT to complete system impact studies for net metering arrangements involving large loads (≥ 75 MW) and existing stand-alone generation resources. This process represents a major step in bringing transparency and structure to how behind-the-meter (BTM) large load interconnections will interact with existing generation across the ERCOT grid.
ERCOT’s Role Under Section 39.169
ERCOT is responsible for determining which Resources qualify as stand-alone generation resources as of 09/01/2025, and for conducting the required system impact studies. ERCOT’s filing with the Public Utility Commission of Texas (PUCT) outlines:
- The methodology for identifying stand-alone generation resources that will be subject to ERCOT’s study.
- The anticipated scope of ERCOT’s evaluation of the system impacts of proposed net metering arrangements.
- ERCOT’s form of notice that owners of existing Resources will need to provide to invoke the Section 39.169 review process
Once a notice of proposed net metering arrangement is provided, ERCOT must:
- Complete the system impact study (following the Large Load Interconnection Study (LLIS) performed by the TSP).
- Deliver the study results and recommendations to the PUCT within 120 days of receiving a complete package.
- The PUCT then has 60 days to either approve the arrangement, deny it, or approve it with conditions necessary to protect reliability.
Exemptions from the Study Requirement
Not every project will trigger ERCOT’s Section 39.169 review. Two specific exemptions apply:
- Pre-registered co-located loads: If a Resource’s original ERCOT registration already listed a large-load customer at the site when the plant first came online.
- Common ownership: If, as of January 1, 2025, the generation facility is majority-owned (directly or indirectly) by the same parent company as the large-load customer.
Entities seeking to claim an exemption must submit supporting documentation to ERCOT along with a notarized attestation. ERCOT will review the filing in consultation with PUCT staff and provide confirmation if the exemption applies.
Why This Matters
Net metering arrangements between large loads and stand-alone generation resources now require ERCOT’s review and PUCT approval under PURA Section 39.169. This adds new regulatory steps and timelines that developers must plan for. Understanding whether your project qualifies for review or an exemption is essential to avoid delays and keep interconnection plans on track.
How EPE Can Help
At Electric Power Engineers (EPE), we support developers and large-load customers navigating this evolving regulatory landscape by providing:
- Interconnection application and modeling support (PSS®E and PSCAD) to meet ERCOT’s technical requirements.
- Transmission and system impact analysis to anticipate ERCOT’s evaluation outcomes.
- Exemption documentation support to ensure filings under Section 39.169(b) are complete
- Timeline management to align LLIS, ERCOT study, and PUCT review deadlines with project schedules.
As PURA Section 39.169 reshapes large load interconnection in ERCOT, proactive planning is essential to avoid delays and ensure compliance. EPE is here to guide you through each step of the process. Contact our team of experts today using the form below.
