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Interconnection Standards

Savings Category 
Fuel Cells
Program Info
Program Type 
Public Utility Commission of Texas

The Texas Public Utility Regulatory Act (PURA) of 1999 included a provision that "a customer is entitled to have access to on-site distributed generation". As a result, the Public Utility Commission of Texas (PUCT) adopted interconnection standards in 1999. The rules apply to electrical generating facilities (consisting of one or more on-site distributed-generation units) located at a customer's point of delivery, with a maximum capacity of 10 megawatts (MW) and connected at a voltage less than 60 kilovolts (kV). The total capacity of a facility's individual on-site distributed generation units may exceed 10 MW. However, no more than 10 MW of capacity will be interconnected at any point in time at the point of common coupling.

The following conditions apply to Texas's interconnection rules for distributed generation:
* Installations must meet all applicable national, state and local construction and safety codes;
* No pre-interconnection study fees are required for units up to 500 kW (under most circumstances), and study fees for larger systems are limited;
* Time limits apply to pre-interconnection studies and application approval or rejection (4-6 weeks);
* Pre-certification provisions allow for fast-track interconnection;
* Equipment and operational requirements are differentiated based on connection type (single-phase or three-phase), paralleling mode and system size;
* Cut-off points exist at 10 kW, 50 kW*, 2 MW** and 10 MW***;
* The rules include technical provisions for interconnection to radial as well as network distribution systems;
* An external disconnect device is required for all systems;
* Standardized interconnection applications and interconnection agreements are used;
* Liability is limited; and
* Owners of distributed renewable generation and independent school district solar generation of 2 MW or less may not be required to purchase additional liability insurance

The PUCT's ''[ Distributed Generation Interconnection Manual]'' includes a review of safety and technical requirements of DG installations; a copy of applicable rules, application procedures and forms; Texas utility contacts; and equipment pre-certification requirements.

''*Texas Statute [ 39.554(e)(1)] permits owners of a Distributed Renewable Generation system to interconnect through a single meter if they have a qualifying facility with a design capacity of 50 kW or less. Overall, Texas does not meet the definition of net-metering as generally understood.''

''**The Public Utility Commission of Texas (PUCT) Substantive Rule § 25.217(b)(1) defines Distributed Renewable Generation (DRG) as generation equipment with a capacity of 2MW or less provided by renewable energy technology. Owners of DRG systems are required to provide proof that equipment carries a warranty against breakdown and undue degradation for a minimum of 5 years. Further information on DRG Interconnection Guidelines can be found on the PUCT Distributed Generation web site listed at the top of this page.

''***The Public Utility Commission of Texas Substantive Rule § 25.217(b)(3) permits interconnection of unlimited generation capacity for Independent School District Solar Generation (ISD-SG). Systems must meet applicable compliance requirements detailed in § 25.211 and § 25.212. Further information on ISD-SG Interconnection Guidelines can be found on the PUCT Distributed Generation web site listed at the top of this page.