ATC Methodology

This page contains BPA’s ATC methodologies for both the NERC (short-term) and Planning (long-term) horizons and other related information. You can find tools and reports to help evaluate and analyze transmission availability here. 

Effective 10/1/2023, BPA does not calculate ATC for the for the flow-based paths (Map of Long-Term BPA Constraints) in the long-term planning time horizon (beyond 13 months through 10 years).  Commercial powerflow studies are performed to evaluate whether transmission service requests and/or Network Load and resource forecasts, impacting flow-based constraints during this time period, can be granted or require additional study to identify transmission system upgrades necessary to reliably offer transmission service.

NERC Horizon (0 - 13 months)

ATC Implementation Document, V79
(Effective 12/15/2023)

ATC Implementation Document Version History
(Effective 12/15/2023)

TRM Implementation Document, V9 (MOD-008-1) (Effective 09/27/2023)

CBM Implementation Document (Effective 04/14/2023)

System Operating Limits Methodology for the Operations Horizon

Map of Short-term BPA Constraints (Effective 12/15/2023)

Data Request Form (MOD-001-1 R9) *
(07/28/2020) 

TTC Study Report Request Form (MOD-029-1 R4) *
(08/29/2019) 

* The forms above are only for use by the specific entities identified in each form. Send all completed forms to nercatcstandards@bpa.gov with the name of the form in the subject line.

Reference Documents

Contact Information

Please send any data-sharing requests, questions about BPA’s TTC/ATC/TRM/CBM methodologies, and/or documents pertaining to specific requirements in the NERC ATC Standards or NAESB WEQ-023 to nercatcstandards@bpa.gov.  Please specify the nature of your request in the subject line.  For general comments or questions about ATC, email techforum@bpa.gov and specify “ATC-related” in the subject line.

To receive emails about ATC Methodology updates and Customer Involvement meetings, select the techforum mail list check box on the sign-up form.

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