Distributed Generation Guidelines for Customer-Owned Generation

Federal Energy Regulator Commission (“FERC”) provides standards for small generation (less then 20 MW) interconnection for facilities within the jurisdiction of the commission. This generally applies to transmission-level interconnection. Distribution-level interconnection is usually regulated by each state's public utilities commission.

Generator interconnections to the Southwestern Public Service Company (“SPS”) distribution system, not subject to Southwest Power Pool (“SPP”) Open Access Transmission Tariff (“OATT”), may still require studies to identify impacts on SPS’s transmission system. SPS will notify SPP of interconnection requests of 5 MW or more to be studied pursuant to SPP’s Affected System Generation Interconnection Impact study process (“Impact Study or Studies”). SPP and/or SPS will evaluate each interconnection request not subject to OATT requirements and will make the final determination whether the interconnection impact study will be performed by SPP. In instances where further study is warranted, such studies will be performed by SPP, at the direction of SPS. Non-jurisdictional generator interconnection customers may be required to enter into the appropriate study agreements with SPP to facilitate an Affected System Agreement. Additionally, requests for non-jurisdictional generator interconnections may be required to be coordinated with SPP in accordance with North American Electric Reliability Corporation (“NERC”) standards.

Although such studies may be performed within SPP’s Generation Interconnection Process (“GIP”) for planning purposes, the non jurisdictional generator interconnection customer will not be subject to the OATT. In such instances, the following shall apply:

1. When notified, SPP is responsible for conducting any required studies to determine if the request may impact the Transmission System.
2. Should SPP determine that the generator interconnection may impact the Transmission System, SPP shall notify SPS of such impacts and provide to SPS any system impact studies that detail such impacts.
3. As an impacted system, SPP will determine what additional studies will be required to coordinate the impacts, up to and including studying the impact in the Definitive Interconnection System Impact Studies (“DSIS”). SPS shall require as a condition of interconnection with the generation customer making request for interconnection, that all SPP required studies be completed. SPS shall have the option to enter into the applicable Affected System study agreements and to be financially responsible for such studies, or as a condition of interconnection, to require the interconnection customer to submit a request to enter the DSIS process or other SPP study process as applicable.
4. It shall remain SPS’s responsibility to complete any generator interconnection agreements in accordance with SPS’s generator interconnection procedures regarding the completion of Network Upgrades required on the Distribution System and on SPS’s Transmission System.

Distributed generation in excess of the net distribution load on a substation will result in power flowing into the transmission system.  Net distribution load is the sum of the traditional load and any pre-existing generation under normal operating conditions.  For this situation, the substation is considered an impact to the transmission system and could require upgrades.  Facilities 2 MW and less may be eligible for the fast track process in lieu of the DISIS.
SPS shall have the option to enter into the applicable Affected System study agreements and to be financially responsible for such studies, or as a condition of interconnection, to require the interconnection customer to submit a request to enter the DSIS process or other SPP study process as applicable.

Impact Studies are performed in a “cluster” method twice a year in April and October. SPS will require the party requesting interconnection to provide initial funding in the amount of $30,000 to determine if upgrades will be needed to the effected transmission system. All funding and DG generator interconnection information must be provided to SPS no less than 30 days prior to April or October. Impact Studies typically take four to six months to be completed. Multiple studies and additional funding are always a possibility. After the SPP Impact Study process is completed and provided to SPS, SPS will contact the party requesting interconnection with any transmission system upgrades required along with the distribution system upgrades. If any funding is not used for the Impact Study, it will be refunded to the party requesting interconnection.

Links to the current PUCT rules relating to Distributed Generation are below. A Distributed Generation Interconnection Manual was created by the PUCT to be used with the current rules. For more information about the interconnection manual see the Interconnection Forms and Agreements section below and for information on the upcoming rules see the New Developments section below.

• State PUCT Rule 25.211 - Interconnection of On-Site Distributed Generation
• State PUCT Rule 25.212 - Technical Requirements for Interconnection and Parallel Operation of On-Site Distributed Generation
• State PUCT Rule 25.213 - Metering for Distributed Renewable Generation
• State PUCT Rule 25.217 - Distributed Renewable Generation - Administration of Renewable Energy Credits (RECs)
• State PUCT Rule 25.242 - Arrangements Between Qualifying Facilities and Electric Utilities
• State PUCT Rule 25.173 - Goal for Renewable Energy and Renewable Energy Credits (“RECs”)
• General PUCT Electric Rules

Texas tariffs relating to distributed generation can be found in section IV of the Texas Electric Rate Book.

Xcel Energy Texas Electric Rate Book

• Section IV-77 - Electric Service to a Qualifying Facility of Aggregate Generation Capacity of 100kW of Less
• Section IV-86 - Energy Purchase from a Qualifying Facility of Aggregate Generating Capacity of 100kW of Less
• Section IV-117 - Purchase of Non-Firm Energy from Qualifying Facility
• Section IV-159 - Distributed Generation Interconnection and Fee Schedule
• Section IV-179 - Primary Qualifying Facility Standby Service
• Section IV-180 - Secondary Qualifying Facility Standby Service

A detailed description of the interconnection process can be found in the document, “Distributed Generation Interconnection Manual”, below. The manual also includes interconnection applications and agreements.

• Distributed Generation Interconnection Manual (pdf)
  • PUCT Rules
  • Technical Summary
  • Utility Processing of DG Applications
    • Flow Charts
  • Cost/Benefit Impacts of DG
  • DG Applicant information
    • Interconnection Process
  • Appendices
    • Copy of PUCT Rules, Forms, and PURA 1999 Excerpts
    • Interconnection Application
    • Interconnection Agreement
    • Summary of DG Technologies

Distributed Generation Interconnection Information

Brian G. Fleming
Xcel Energy Services – Resource Planning
600 S. Tyler, Suite 2900
Amarillo, TX 79101
Phone: 806-378-2460
Fax: 806-378-2995
Email: Brian.Fleming@xcelenergy.com

Transmission Voltage Interconnection Information

Annette Gallegos
Principal Transmission Representative
Phone: 806-640-6302
Email: Annette.Gallegos@xcelenergy.com