The CMEEC Ambient Adjusted Ratings Submitter (CAARS) platform, developed in-house by CMEEC staff, provides a fully automated, reliable solution for managing the Ambient Adjusted Rating (AAR) submissions required under FERC Order No. 881. By combining customer-provided rating tables with weather forecasts from a trusted source, CAARS streamlines hourly AAR calculations, submissions and tracking, reducing operational burden while enabling continuous compliance.

Supported by CMEEC’s decades of BI and energy industry expertise, secure submission tracking tools and resilient system design, CAARS offers a simple, dependable path to fulfilling evolving transmission rating requirements. CAARS is accepting new customers. Those interested in learning more about the platform are encouraged to contact CMEEC’s BI Department at bi@cmeec.org.
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Context

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FERC Order No. 881 requires the provision of AARs to the regional Independent System Operators (ISOs), effective in ISO-NE territory on November 17, 2026. The AARs must be calculated and submitted to ISO-NE every hour, 24 hours a day, and each submission must include forecasted ratings for the following 72-hour period. While not required or currently accepted by the ISO-NE Limit Exchange Portal (LEP), the CAARS platform is also capable of calculating, submitting and tracking forecasted ratings for the following 240-hour period.

The CAARS platform is designed to simplify compliance with FERC Order No. 881 in ISO-NE territory. Using rating tables and forecasted weather data, the CAARS platform automatically calculates the appropriate AARs, submits them to the ISO-NE LEP and updates the CAARS Tracker.
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Key Features


Full Automation icon   Full Automation
After initial setup, the CAARS calculation, submission, and validation process is fully automated, requiring no user intervention beyond initial setup unless changes are required or desired. The platform calculates AARs using rating tables initially provided by the customer and weather forecasts from a trusted source, submits the AARs to the ISO-NE LEP, and verifies each submission. This solution eliminates the financial and operational burden associated with creating and sustaining in-house systems for the hourly AAR submissions required for continuous compliance.

 CAARS Tracker icon   CAARS Tracker
The CAARS Tracker is a secure web portal that uses individual accounts with MFA. It is designed for users to view their full CAARS submission history - including AARs submitted, submission times, and ISO-NE LEP validation history.

 Human Review icon   Human Review
Backed by the experienced CMEEC staff behind the trusted CMARS application, the CAARS platform is routinely monitored to ensure smooth operation, apply necessary updates, and notify customers as needed.

 Adaptive design icon    Adaptive Design
The CAARS platform can easily incorporate updated rating tables, offering flexibility when transmission equipment or calculation methodologies change.

 Backup systems icon   Backup Systems
The backup processes and redundant servers that CMEEC uses throughout its operations support the CAARS platform, helping to avoid or minimize disruptions following physical or cyber emergencies.

 Group icon   Public Power
CMEEC, a Joint Action Agency of municipally owned electric utilities, created the CAARS platform to help its members comply with FERC Order No. 881. The same high level of service is offered to third-party customers.

CAARS Tracker Interface

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CAARS Tracker_Forecasted Ratings
Forecasted AARs for specific dates and times are among several data points available on the CAARS Tracker.

Learn More


To learn more about our CAARS platform or to schedule a consultation, please email bi@cmeec.org.