ATC Methodology Transmission Services has developed methodologies for calculating its available transfer capability (ATC) for both long-term and short-term transmission service. This methodology does not currently use Capacity Benefit Margins (CBM) in the calculation of ATC and ATC is not decremented by CBM for either normal or emergency conditions. Information including official documentation, tools and assumptions, customer comments and access to the active work group is accessible below. Any general queries on either the long-term or short-term ATC methodologies should be submitted to techforum@bpa.gov.

News and Events ATC Methodology Customer Comments ATC Work Group Related Information Base Case Assumptions NT Resources Memorandum of Agreement (MOA) (1.68 MB PDF) 7/27/05 Long-Term Firm (LTF) PUF Calculator (874k XLS) 6/5/2008 Short Term Firm (STF) PUF Calculator (141k XLS) 10/31/07 Path Utilization Factor (PUF) Tables Updated (825k XLS) 6/5/08 Draft Standards for Available Transfer Capability Comments to NERC ATC Draft Reliability Standards BPA Position on NERC ATC Standards WECC Position on NERC ATC Standards BPA Comments to NERC on ATC Standards BPA Comments to NERC on ATC

ATC Methodology ATC Methodology, V5 ATC Methodology Margin (AMM)/De Minimis, V8 Long-Term Network Flowgates, Version 2 (95k PDF) 10/31/2007 Contract Accounting Methodology, V5 ATC Impacts of Long-Term Firm Requests, V5 TTC for Network Flowgates, V4 Power Flow Base Case, V5 Short-Term Firm ATC Methodology, V3 (227k PDF) 1/30/2008 Short-Term Network Flowgates (86k PDF) 2/1/2008 ATC AMM Postings 6/8/2007