Solar PV Systems Engineering & Compliance
Budget: $5,000 – $10,000 USD
Electrical Engineering, ETAP Modeling, and Utility Interconnection Design
Rincon Solar Portfolio – Ventura, CA (SCE Rule 21 Interconnection)
1. PROJECT OVERVIEW
Off Grid Innovations (OGI Solar) is developing a portfolio of solar PV systems interconnected to an existing 16 kV distribution system in Ventura, California under SCE Rule 21.
USE LINK TO ACCESS ETAP FILES - https://drive.google.com/drive/folders/1aN1qzIla95ePidneG5kcH51k2QmXjJGv?usp=drive_link
Total System Size: ~12.3 MW AC
Voltage: 16 kV primary distribution
Interconnection: SCE Grandad 16 kV Circuit (Casitas Substation)
The purpose of this scope is to engage a qualified engineering firm to provide:
Full power system modeling (ETAP)
Protection & coordination design
Medium voltage interconnection engineering
Utility (SCE) compliance package
IFC-level design deliverables
2. OBJECTIVE
Deliver a complete, utility-c
ompliant engineering package that:
Supports procurement (equipment POs immediately)
Meets SCE Rule 21 interconnection requirements
Enables rapid submission of design package to SCE
Avoids redesign or restudy triggers
3. DETAILED SCOPE OF SERVICES
3.1 ETAP MODEL DEVELOPMENT & VALIDATION
Engineer shall:
Review and validate existing ETAP model (if provided)
Develop complete ETAP model of:
16 kV distribution system
All PV generation sites
Transformers, feeders, switchgear, and loads
Confirm:
Transformer impedances and ratings
System topology vs field conditions
Equipment interrupting ratings
Required Studies:
Short Circuit Analysis (utility + PV contribution)
Load Flow Analysis (normal + contingency)
Voltage drop / regulation analysis
Equipment duty validation (AIC checks)
Expanded Requirements (SCE-driven):
Model fault contribution and SCCR compliance
(SCE identified SCCR exceedance)
Model reverse power flow impacts
Validate inverter fault contribution assumptions
3.2 PROTECTION & COORDINATION STUDY (FULL SCOPE)
Engineer shall provide a complete protection study, including:
Time-Current Coordination (TCC curves)
Relay coordination across:
Utility interconnection
MV distribution
Transformer secondaries
Selectivity analysis (upstream vs downstream)
MUST INCLUDE:
Multiple operating scenarios:
All PV online
Partial generation scenarios
Fault conditions at POI
Identification of:
Equipment rating violations
Mis-coordination risks
Deliverables:
Protection philosophy document
Relay settings
Coordination plots
Mitigation recommendations
Note: SCE explicitly requires a coordination study during final engineering
3.3 MEDIUM VOLTAGE (16 kV) INTERCONNECTION ENGINEERING
Engineer shall design the full MV system including:
Interconnection to SCE circuit at POI
Transformer configuration and grounding
MV cabling, routing, and protection
REQUIRED UTILITY INTERFACE COMPONENTS:
A. Recloser Integration
Design and integration of:
16 kV Remote Sectionalizing Recloser (RSR-G)
Coordination with system protection
B. Metering Design
Bi-directional metering system design
CT/PT sizing and placement
Revenue-grade metering compliance
C. AC Disconnect / Switching
Evaluate and design required switching scheme
Confirm compliance with utility isolation requirements
3.4 RTU, SCADA, AND TELECOMMUNICATIONS DESIGN
Engineer shall provide full design for utility communication interface:
RTU Requirements:
Integration of dedicated RTU system
Monitoring of:
MW / MVAR
Voltage
Breaker status
Telecommunications:
Design communication pathway to SCE EMS:
T1 circuit interface
Signal architecture
Termination design
Deliverables:
Communication diagrams
RTU wiring diagrams
Data point mapping list
3.5 DAS / EMS INTEGRATION SUPPORT
Engineer shall coordinate with DAS/EMS provider (e.g., Wave, AlsoEnergy, etc.) to:
Ensure compatibility with:
RTU system
Utility telemetry requirements
Provide:
Data mapping architecture
Integration requirements for DER monitoring
3.6 SCE DESIGN PACKAGE (SUBMITTAL READY)
Engineer shall produce a complete SCE-compliant design package, including:
IFC Single Line Diagrams
Protection and control schematics
Equipment specifications and cut sheets
Site plans and electrical layouts
Switchgear drawings compliant with SCE ESR requirements
Must Support:
SCE design review process
Interconnection Agreement compliance
Rapid approval (no redesign loops)
3.7 COMMISSIONING & COMPLIANCE SUPPORT
Engineer shall support:
Pre-commissioning validation
Utility witness testing
Final commissioning testing per Rule 21
3.8 REGULATORY & TECHNICAL COMPLIANCE
Design must comply with:
SCE Rule 21 requirements
Smart inverter requirements
Ramp rate requirements
Utility protection standards
Wildfire mitigation considerations (if applicable)
4. DELIVERABLES
At minimum, engineer shall provide:
ETAP model (editable format)
Short circuit & coordination study report
Protection settings and TCC curves
Full IFC drawing set
Communication / RTU diagrams
SCE-ready design package
Engineering memo with findings & recommendations
5. SCHEDULE REQUIREMENTS (CRITICAL)
Project is on an accelerated timeline.
Initial ETAP model + preliminary results: ≤ 7 days
Protection study + coordination: ≤ 10–14 days
Full IFC design package: ≤ 2–3 weeks
Must support equipment procurement by next week
6. QUALIFICATIONS
Firm must demonstrate:
Experience with SCE Rule 21 interconnections
Strong ETAP modeling capabilities
Proven MV protection & coordination experience
Experience with utility RTU / SCADA integration
7. EXCLUSIONS (NOT ALLOWED UNLESS EXPLICITLY STATED)
The following cannot be excluded unless clearly noted in proposal:
Protection coordination study
MV interconnection design
RTU / telecom integration
Utility compliance support
Rincon Solar Portfolio – Ventura, CA (SCE Rule 21 Interconnection)
1. PROJECT OVERVIEW
Off Grid Innovations (OGI Solar) is developing a portfolio of solar PV systems interconnected to an existing 16 kV distribution system in Ventura, California under SCE Rule 21.
USE LINK TO ACCESS ETAP FILES - https://drive.google.com/drive/folders/1aN1qzIla95ePidneG5kcH51k2QmXjJGv?usp=drive_link
Total System Size: ~12.3 MW AC
Voltage: 16 kV primary distribution
Interconnection: SCE Grandad 16 kV Circuit (Casitas Substation)
The purpose of this scope is to engage a qualified engineering firm to provide:
Full power system modeling (ETAP)
Protection & coordination design
Medium voltage interconnection engineering
Utility (SCE) compliance package
IFC-level design deliverables
2. OBJECTIVE
Deliver a complete, utility-c
ompliant engineering package that:
Supports procurement (equipment POs immediately)
Meets SCE Rule 21 interconnection requirements
Enables rapid submission of design package to SCE
Avoids redesign or restudy triggers
3. DETAILED SCOPE OF SERVICES
3.1 ETAP MODEL DEVELOPMENT & VALIDATION
Engineer shall:
Review and validate existing ETAP model (if provided)
Develop complete ETAP model of:
16 kV distribution system
All PV generation sites
Transformers, feeders, switchgear, and loads
Confirm:
Transformer impedances and ratings
System topology vs field conditions
Equipment interrupting ratings
Required Studies:
Short Circuit Analysis (utility + PV contribution)
Load Flow Analysis (normal + contingency)
Voltage drop / regulation analysis
Equipment duty validation (AIC checks)
Expanded Requirements (SCE-driven):
Model fault contribution and SCCR compliance
(SCE identified SCCR exceedance)
Model reverse power flow impacts
Validate inverter fault contribution assumptions
3.2 PROTECTION & COORDINATION STUDY (FULL SCOPE)
Engineer shall provide a complete protection study, including:
Time-Current Coordination (TCC curves)
Relay coordination across:
Utility interconnection
MV distribution
Transformer secondaries
Selectivity analysis (upstream vs downstream)
MUST INCLUDE:
Multiple operating scenarios:
All PV online
Partial generation scenarios
Fault conditions at POI
Identification of:
Equipment rating violations
Mis-coordination risks
Deliverables:
Protection philosophy document
Relay settings
Coordination plots
Mitigation recommendations
Note: SCE explicitly requires a coordination study during final engineering
3.3 MEDIUM VOLTAGE (16 kV) INTERCONNECTION ENGINEERING
Engineer shall design the full MV system including:
Interconnection to SCE circuit at POI
Transformer configuration and grounding
MV cabling, routing, and protection
REQUIRED UTILITY INTERFACE COMPONENTS:
A. Recloser Integration
Design and integration of:
16 kV Remote Sectionalizing Recloser (RSR-G)
Coordination with system protection
B. Metering Design
Bi-directional metering system design
CT/PT sizing and placement
Revenue-grade metering compliance
C. AC Disconnect / Switching
Evaluate and design required switching scheme
Confirm compliance with utility isolation requirements
3.4 RTU, SCADA, AND TELECOMMUNICATIONS DESIGN
Engineer shall provide full design for utility communication interface:
RTU Requirements:
Integration of dedicated RTU system
Monitoring of:
MW / MVAR
Voltage
Breaker status
Telecommunications:
Design communication pathway to SCE EMS:
T1 circuit interface
Signal architecture
Termination design
Deliverables:
Communication diagrams
RTU wiring diagrams
Data point mapping list
3.5 DAS / EMS INTEGRATION SUPPORT
Engineer shall coordinate with DAS/EMS provider (e.g., Wave, AlsoEnergy, etc.) to:
Ensure compatibility with:
RTU system
Utility telemetry requirements
Provide:
Data mapping architecture
Integration requirements for DER monitoring
3.6 SCE DESIGN PACKAGE (SUBMITTAL READY)
Engineer shall produce a complete SCE-compliant design package, including:
IFC Single Line Diagrams
Protection and control schematics
Equipment specifications and cut sheets
Site plans and electrical layouts
Switchgear drawings compliant with SCE ESR requirements
Must Support:
SCE design review process
Interconnection Agreement compliance
Rapid approval (no redesign loops)
3.7 COMMISSIONING & COMPLIANCE SUPPORT
Engineer shall support:
Pre-commissioning validation
Utility witness testing
Final commissioning testing per Rule 21
3.8 REGULATORY & TECHNICAL COMPLIANCE
Design must comply with:
SCE Rule 21 requirements
Smart inverter requirements
Ramp rate requirements
Utility protection standards
Wildfire mitigation considerations (if applicable)
4. DELIVERABLES
At minimum, engineer shall provide:
ETAP model (editable format)
Short circuit & coordination study report
Protection settings and TCC curves
Full IFC drawing set
Communication / RTU diagrams
SCE-ready design package
Engineering memo with findings & recommendations
5. SCHEDULE REQUIREMENTS (CRITICAL)
Project is on an accelerated timeline.
Initial ETAP model + preliminary results: ≤ 7 days
Protection study + coordination: ≤ 10–14 days
Full IFC design package: ≤ 2–3 weeks
Must support equipment procurement by next week
6. QUALIFICATIONS
Firm must demonstrate:
Experience with SCE Rule 21 interconnections
Strong ETAP modeling capabilities
Proven MV protection & coordination experience
Experience with utility RTU / SCADA integration
7. EXCLUSIONS (NOT ALLOWED UNLESS EXPLICITLY STATED)
The following cannot be excluded unless clearly noted in proposal:
Protection coordination study
MV interconnection design
RTU / telecom integration
Utility compliance support