We use three OASIS sites to serve transmission customers and an OATT for tariff and formula rate matters.

Open Access Same Time Information System (OASIS)

The OASIS sites are used for customers to request transmission services and to designate and terminate network resources and for the transmission providers to post some of the Federal Energy Regulatory Commission (FERC) required postings, such as business practices, transfer capacity, transmission service products and prices.

Xcel Energy transmission providers use the following OASIS sites:

Open Access Transmission Tariff (OATT)

All public utilities that own, control or operate transmission are required by FERC to provide an Open Access Transmission Tariff (OATT). The OATT, in essence, defines how we run our transmission business.

The main Open Access Transmission Tariff (OATT) documents below cover our entire service area. All files can be viewed using Acrobat Reader. Note the large file sizes may have long download times.

Formula Rate Matters

As part of the OATT, Xcel Energy is required by FERC to make our formula rates available to the public.

NSP Formula Rate Matters

SPS Formula Rate Matters

Process to Modify