Generation Exceeding 20 MW (Transmission System)

The connection of generators exceeding 20 MW is subject to the Large Generator Interconnection Procedures (LGIP) contained in the TEP Open Access Transmission Tariff (OATT), which is approved by the Federal Energy Regulatory Commission (FERC).

To request interconnection, applicants must complete an Interconnection Request, which is Appendix 1 of the OATT.  Please email your completed Interconnection Request form to and submit your refundable deposit and any required site control or deposit in lieu of site control. If your project proceeds to the study phase, TEP will apply your deposit toward the cost of processing your request and any required studies.


  • Complete the Interconnection Request application (Appendix 1 along with any other appendices) and email the form to
  • Submit a refundable deposit of $10,000 for each site to TEP
  • Provide Site Control or an additional deposit of $10,000


  • Acknowledge receipt of your application within 5 business days
  • Notify you if the application is incomplete or there are deficiencies
  • Assign your project a study queue number once your application is deemed complete
  • Hold a Scoping Meeting with you
  • Issue you a Feasibility Study Agreement (FeasA) or System Impact Study Agreement (SISA)

The Study Process

The amount of generation that you are seeking to interconnect to TEP’s transmission system will determine the studies needed prior to receiving an Interconnection Agreement. The Feasibility Study is optional, while the System Impact and Facility Studies are required.

Once you have submitted your application and deposit to TEP, you will be assigned a queue number based on when your application and deposit were received, and the study process will begin.

TEP utilizes clustering based on geographical area for conducting the System Impact Study (SIS), which is the first of two required studies that TEP will conduct. Your project will be assigned to one of two queue cluster windows on OASIS, depending on when your Interconnection Request was received.

NOTE: Customers may withdraw from the study process at any phase by notifying us by email at