will be offline on Saturday, Oct. 23 from 6:00 am MDT to noon MDT due to Reston Data Center maintenance.

Yosemite Valley Generator Hub

Yosemite National Park » Yosemite Valley Generator Hub » Document List

The proposed project is to create a generator hub in order to provide backup electrical power service to the Yosemite Valley when a power outage occurs. Currently, when commercial power is lost in Yosemite Valley establishing backup power is extremely costly and time consuming. Delays restoring power negatively impact emergency communications, government housing, park offices, and guest services.

The proposed project will create one central space for one large mobile generator to be trucked into the park and connected to a switch gear box and step-up transformer (situated on new concrete pad) to restore power. The hub will be located between the existing Valley substation and the building immediately to the east (current park offices). This area has been extensively impacted by previous construction and utility trenching. Equipment and materials staging for this construction effort is anticipated to occur in the vicinity of the job site on existing paved surfaces.

Project scope:
• New concrete pad approximately 4-feet by 8-feet by 6-inches deep
• Removal of four pine trees ranging in diameter from 12-inches to 24-inches
• Installation of underground electrical conduits. Trenching estimate: 18-24 inches deep spanning 2-3 feet across running from new transformer and switch to substation
• Removal of existing storage shed (contents to be relocated to other existing storage facilities in the Valley)
• Switch Gear Box, metal enclosure approx. 3'x4'x3', painted green or grey
• Step-Up Transformer, metal enclosure approx. 3'x4'x3', painted green or grey

All repairs and improvements shall be completed in accordance with the California Public Utilities Commission General Order 95, Rules for Overhead Electric Line Construction ((