Delivering Grid Interconnection Infrastructure
The Highlander substation included three 500 kV 295 MVA transformers, two 500 kV breakers, thirteen 34.5 kV breakers, twelve circuits with thirteen feeder riser bays, and eight 15 MVAR capacitor banks providing 120 MVAR of reactive power compensation.
The facility included metering for individual circuits and protection systems designed to meet applicable North American Electric Reliability Corporation (NERC) Protection and Control requirements.
Beyond the substation, Mortenson constructed 1,500 feet of 500 kV transmission line using custom steel monopole structures and 54,000 feet of distribution line on wood monopole structures serving the solar field.
Coordinating Monitoring, Commissioning, and Energization
Mortenson worked with its trade partner to establish the site's SCADA system, enabling remote monitoring of information across the substation and solar array.
As construction neared completion, the project team coordinated utility outages at the 500 kV level and implemented the project's energization plan to safely bring the substation and solar facility online.
Commissioning activities included:
- Testing all substation equipment
- End-to-end testing with the local utility
- Point-to-point checkout verification
- SCADA points list validation
- Proofing protective relays following energization
- Equipment training
- Delivery of final system manuals
Navigating Project Challenges
The project team encountered a lengthy county permitting process and unpredictable weather conditions during delivery. When the COVID-19 pandemic affected project execution, the team implemented measures focused on maintaining worker safety while continuing progress toward project completion.
Through coordination among project stakeholders, utility partners, and project teams, Mortenson delivered the electrical infrastructure required to support the operation of the Spotsylvania solar generation facility.