Nevada Power Company d/b/a NV Energy earlier this month filed with the Public Utilities Commission of Nevada an application for a permit to build a new 230/69-kV auto bank and associated facilities at the Bighorn substation in order to provide reliable electric service to customers in southern Clark County.
The proposed utility equipment includes the installation of the new auto bank; one 230-kV circuit breaker; as well as associated relays, circuits, system protections, telecommunication systems, and related equipment appurtenant to the safe, reliable, and cost-effective operation of those new and existing facilities, the company said.
The Bighorn substation has been in operation since 2002, the company said, noting that since the original construction and development of the substation – as well as of the adjacent Higgins generating station – there are no longer any natural resources present within the substation. All vegetation and native soil were removed to install, among other things, below ground electrical facilities, above ground foundations, electrical equipment and overhead wires, as well as perimeter security and wildlife exclusion fencing.
The company added that no formal environmental impact studies are required now because the project is located wholly on private land within an existing electrical substation. NV Energy said that its personnel did conduct on-site reviews and surveys to further conclude that no additional environmental impacts would occur on the developed land. Short-term impacts due to installation activities may cause fugitive dust, but water would be used to mitigate that, as applicable, the company said. Construction-related noise would be temporary, the company added.
An alternative solution to increase reliability in the area of southern Clark County would be to build a new 230/69-kV substation near Jean or Goodsprings in Nevada, and to fold in a circuit of the existing Arden-Bighorn 230-kV transmission line, the company said, adding, “This would entail a potentially long permitting timeline in addition to likely more significant costs than the proposed project.”
The economics of the various alternatives does not balance the need to increase reliability by alleviating the N-1 condition in that area of southern Nevada, the company said. The proposed facilities would add an additional electric source to the load pocket in the area and alleviate the N-1 condition, according to the company, which also noted that the proposed facilities would have the additional benefit of increasing the voltage and transmission capacity to the area.
Clark County issued a special use permit for the construction and operation of the substation in June 2001, the company said, adding that that permit is still in effect and covers the new proposed facilities.