Medium Voltage Interconnection

One of the best ways to manage extra solar energy is to sell it back to your local electric company. It’s a green choice for the community. Castillo Engineering creates the actual design and hookup needed for medium voltage interconnections from solar PV systems to the electrical company.

Castillo Engineering Services provides high-end designs to hookup the energy that solar PV systems generate to what the electric company accepts. With experience and expertise in solar energy, Castillo Engineering crafts designs that are safe, effective, and high quality.

Designed to Permit

Castillo Engineering creates medium voltage interconnection designs with the permit and utility company regulations in place. This way, less time is spent trying to get the design approved. The company also creates plans that use a minimal bill of materials to reduce costs. After discussing the needs of the project, the team of professional engineers creates the designs, sends them for a QA review, then sends them back to the contractor for feedback.   

Our Services Include

Power Flow Analysis 

  1. General Loading Analysis
  2. Reverse Power Flow
  3. Voltage Analysis
  4. Flicker Analysis
  5. PCC & Revenue Metering Requirements
  6. Additional System Modifications (when required)
  7. Feeder Capacitor Banks

Relay Setting 

  1. SEL 751A Programming & Configuration
  2. SEL 751A Installation

General Interconnection & Protection 

  1. Telemetry & Telecommunications
  2. EMS-RTU

Short Circuit & Protection Analysis 

  1. Over-Voltage Analysis
  2. Fault Current Contributions
  3. Facility Protection Scheme Assessment

Short Circuit & Protection Analysis 

  1. Over-Voltage Analysis
  2. Fault Current Contributions
  3. Facility Protection Scheme Assessment

Inspection, Compliance Verification, Customer Testing, & Energization 

  1. Inspection & Compliance Verification
  2. Testing & Commission
  3. Energization & Synchronization

Incident Energy Analysis (Arch Flash Study) 

  1. One Line Drawing
  2. Arc Flash & Shock Hazard Labeling
  3. Arc Flash Mitigation / Arc Flash Reduction
  4. Coordination Study
  5. Short Circuit Study

Our Expertise

After completing more than 10,000 solar engineering projects over 20 years, Castillo Engineering has experience with code officials and utility companies. The company knows what they are going to need and expect. This expertise streamlines the process and ensures quality designs. 

No matter where a solar PV project is located, there’s a good chance that Castillo Engineering can help. Castillo Engineering is licensed for solar PV engineering projects across the United States, in 40 states. 

Contact Us

Make sure the medium voltage interconnection properly steps up into the utility company’s specifications. Email Castillo Engineering at or call 407-739-1102 for expert solar PV engineering knowledge and quick service for solar PV projects.