40 U.S.C. § 591

1. (a)A department, agency, or instrumentality of the Federal Government may not use amounts appropriated or made available by any law to purchase electricity in a manner inconsistent with state law governing the provision of electric utility service, including—
   1. (1)state utility commission rulings; and
   2. (2)electric utility franchises or service territories established under state statute, state regulation, or state-approved territorial agreements.
2. (b)
   1. (1)This section does not preclude the head of a federal agency from entering into a contract under section 801 of the National Energy Conservation Policy Act (42 U.S.C. 8287).
   2. (2)This section does not preclude the Secretary of a military department from—
      1. (A)entering into a contract under section 2394 1 See References in Text note below. of title 10; or
      2. (B)purchasing electricity from any provider if the Secretary finds that the utility having the applicable state-approved franchise (or other service authorization) is unwilling or unable to meet unusual standards of service reliability that are necessary for purposes of national defense.