Guana Substation Expansion

ChenMoore provided permitting, aesthetics coordination, design, and construction support services for the Guana Substation Expansion (BES) in Ponte Vedra Beach, Florida. Located in a highly visible area of St. Johns County, the project required careful coordination of technical design, constructability, permitting, and visual considerations to support both system reliability and community expectations.

ChenMoore managed the BES permitting process, participated in board meetings related to project appearance, and incorporated aesthetic guidance into the final design to ensure the expanded facility aligned with stakeholder requirements.

The project included significant substation expansion, protection and controls upgrades, and transmission improvements to enhance operational flexibility and accommodate future growth. Major elements included the addition of a new 56 MVA transformer, a new 26 kV low-side bus with capacity for future feeders, and reconstruction of the 138 kV yard into a four-element ring bus configuration with new breakers, switches, buswork, and associated wiring.

ChenMoore also supported project implementation during construction through equipment shop drawing review, coordination with the substation packager, factory witness testing, relay settings, and commissioning support. Transmission relocation was carefully staged so the substation could remain energized throughout construction, using temporary and permanent pole solutions to maintain service continuity, improve stability, and reduce construction

Project Highlight

• Managed BES permitting, board coordination, and aesthetic integration for a high-visibility substation expansion
• Added a new 56 MVA transformer and 26 kV low-side bus with provisions for three future feeders
• Reconfigured the 138 kV yard into a four-element ring bus to improve reliability and operational flexibility
• Supported construction with shop drawing review, equipment coordination, factory witness testing, relay settings, and commissioning
• Designed staged transmission relocation solutions that maintained an energized substation and reduced construction time by approximately three months