Tex. Utilities Code § 38.077

(a) In this section, "critical facility" means a transmission substation and any associated control centers that, if rendered inoperable or damaged because of a physical attack, could cause widespread instability, uncontrolled separation, or cascading outages within an interconnection.

(b) The commission and the independent organization certified for the ERCOT power region under Section 39.151 shall conduct simulated or tabletop load shedding exercises with providers of electric generation service and transmission and distribution service in the ERCOT power region.

The commission shall ensure that each year at least one simulated or tabletop load shedding exercise is conducted during a summer month and one simulated or tabletop load shedding exercise is conducted during a winter month.

(c) The commission and the independent organization certified for the ERCOT power region under Section 39.151 shall conduct simulated or tabletop exercises with providers of electric generation service and transmission and distribution service in the ERCOT power region to mitigate and prepare for a threat of an attack or an actual physical attack on a critical facility. The exercises required by this subsection are in addition to the exercises required by Subsection (b) and any requirements of the North American Electric Reliability Corporation Critical Infrastructure Protection plan standards. The commission and the independent organization shall conduct the exercises under this subsection at least once every two years.

(d) A simulated or tabletop exercise conducted under Subsection (c) must identify the roles and responsibilities of the following in the event of a threat of an attack or an actual physical attack on a critical facility:

(1) transmission and distribution service providers;

(2) providers of electric generation service;

(3) law enforcement;

(4) the independent organization certified for the ERCOT power region under Section 39.151; and

(5) the commission.

(e) A transmission and distribution service provider is not required to disclose the specific location of the provider's critical substations to the commission or the independent organization certified for the ERCOT power region under Section 39.151 for the purposes of a simulated or tabletop exercise conducted under Subsection (c).

(f) Each provider of electric generation service and of transmission and distribution service that participates in a simulated or tabletop exercise conducted under Subsection (c) shall provide to the independent organization certified for the ERCOT power region under Section 39.151 a written attestation that the provider has coordinated with law enforcement when identifying roles and responsibilities under Subsection (d).