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Grid-Tied Electrical System with Solar PV & Battery Storage
A complete electrical distribution design for your 220,000 ft² warehouse — including optional renewable energy and battery storage for cost savings and sustainability.
System at a Glance
Your building’s electrical system is designed as a modern, code-compliant distribution network with optional clean energy generation and intelligent battery storage.
Utility Service
Southern California Edison (SCE) 12.47 kV primary stepped down to 480V through a 750 kVA transformer. Reliable, high-capacity grid connection.
480V 3ΦDistribution
Five dedicated load buses serving office/admin, warehouse lighting, HVAC, conveyor/dock motors, and future expansion — each individually protected.
5 BusesSolar PV Array
Ground-mounted solar array producing up to 750 kW DC with 10 string inverters. Offsets a significant portion of daytime energy use.
0.75 MWBattery Storage
Li-ion NMC battery system for peak shaving and TOU load shifting. Reduces demand charges and provides optional backup for non-critical loads.
375 kW / 0.7 MWh💡 What This Means for You
Your building gets reliable, code-compliant power distribution plus the ability to generate clean energy, store it for peak-rate hours, and reduce your monthly SCE demand charges — all from a single integrated design.
System Architecture
This simplified single-line diagram shows how power flows from SCE through your building’s distribution system. Each branch is individually protected with circuit breakers.
Load Analysis & Power Studies
We analyzed your building’s electrical demand, power flow, fault conditions, and equipment sizing. Here’s a summary of the key findings.
Equipment Loading
⚠️ Feeder F2 (Lighting) Near Capacity
The warehouse lighting feeder is at approximately 95% of rated capacity. If additional lighting or equipment is planned for this circuit, we recommend upsizing the conductor from 2/0 AWG to 4/0 AWG to maintain adequate margin.
Voltage Profile — All Within Limits
| Bus Location | Voltage (V) | Per-Unit | Drop (%) | Status |
|---|---|---|---|---|
| Main LV Bus | 480.0 | 1.000 | 0.00% | ✓ Pass |
| LV Bus 1 – Office | 479.3 | 0.998 | 0.15% | ✓ Pass |
| LV Bus 2 – Lighting | 478.5 | 0.996 | 0.32% | ✓ Pass |
| LV Bus 3 – Motors | 478.7 | 0.996 | 0.22% | ✓ Pass |
| LV Bus 5 – Future | 479.1 | 0.998 | 0.18% | ✓ Pass |
NEC limit: ±5% of nominal. All buses at ±0.5% — excellent voltage regulation.
Safety & Protection
Worker safety is built into every aspect of the design. Arc flash hazard levels, required PPE, and equipment fault ratings have all been analyzed per IEEE and NFPA standards.
Arc Flash PPE Categories by Location
✅ No Locations Exceed 40 cal/cm²
All equipment locations fall within standard NFPA 70E PPE categories. No arc flash mitigation measures (arc-resistant switchgear, zone-selective interlocking) are required at this time. Labels will be applied to all panels per NFPA 70E 130.5(H).
Equipment Fault Protection
| Equipment | Rated Capacity | Max Available Fault | Utilization | Status |
|---|---|---|---|---|
| Main LV Breaker | 35 kA | 21.2 kA | 61% | ✓ Adequate |
| Feeder Breakers (F1–F5) | 35 kA | 19.8 kA | 57% | ✓ Adequate |
| PV / BESS Breaker | 35 kA | 3.5 kA | 10% | ✓ Adequate |
| Panelboards | 25 kA | 19.8 kA | 79% | ✓ Adequate |
Renewable Energy & Battery Storage
The optional solar PV and battery storage system are designed to reduce operating costs, shift load away from expensive peak-rate hours, and provide limited backup capability.
☀️ Solar PV System
Ground-mounted array on ~6 acres of available land.
🔋 Battery Energy Storage
Li-ion NMC system for peak shaving and resilience.
💰 How the Battery Saves Money
SCE charges demand rates based on your highest 15-minute peak each month. The BESS shaves 375 kW off your peaks during expensive TOU hours, directly reducing demand charges. Excess solar energy is stored during midday and discharged during evening peak rates — buying low, selling high from your own roof.
Code Compliance & Quality Checks
The design has been checked against all applicable electrical codes and industry standards. Green items are confirmed compliant; yellow items require utility or vendor confirmation.
| Code / Standard | What It Covers | Status |
|---|---|---|
| NEC (NFPA 70) | Wiring, grounding, overcurrent protection, PV, BESS | ✓ Compliant |
| IEEE 1584-2018 | Arc flash hazard calculations | ✓ Compliant |
| IEEE 1547-2018 | Solar/BESS grid interconnection | ✓ Compliant |
| IEEE 519-2022 | Power quality / harmonics at PCC | ✓ Compliant |
| IEEE 80 | Grounding grid — touch & step voltage | ✓ Compliant |
| IEEE C37 Series | Breaker ratings vs. fault current | ✓ Compliant |
| NFPA 70E | Arc flash labels & safe work practices | ✓ Compliant |
| NFPA 855 | Battery storage installation safety | ✓ Compliant |
| NFPA 780 | Lightning protection system | ✓ Compliant |
| SCE Rule 21 | Utility interconnection tariff | ⏳ Pending — application needed |
| UL 1741 SA | Inverter safety listing | ⏳ Pending — vendor confirmation |
| CA Title 24 | State energy code amendments | ✓ Compliant |
Cross-Reference Verification — 12 of 12 Checks Passed
What Happens Next
This preliminary design is ready for your review and approval. Once you confirm the approach, here’s how we move forward.
📋 Customer Approval of Preliminary Design
You review this proposal and confirm the system architecture, load allocations, DER options, and equipment approach. Flag any changes to scope or requirements.
🔌 Utility Coordination (SCE Rule 21)
Submit interconnection application to SCE. Confirm available fault current, export limits, metering, and telemetry requirements. This is on the critical path.
📐 Detailed Engineering & PE Review
A licensed Professional Engineer reviews all calculations, runs ETAP/SKM software verification, finalizes TCC curves with manufacturer data, and stamps the package.
🏗️ AHJ Plan Review & Permitting
Submit stamped drawings to the Authority Having Jurisdiction for electrical permit. Address any plan check comments.
📦 Equipment Procurement
Order long-lead items: transformer (12–16 weeks), BESS racks (16–20 weeks), PV modules (8–12 weeks). Early procurement reduces schedule risk.
⚡ Construction & Commissioning
Install electrical distribution, PV arrays, BESS container, and grounding grid. Perform functional testing, relay commissioning, and arc flash label installation.
🔑 Key Decisions Needed From You
1. Confirm DER scope — proceed with solar PV and/or BESS, or defer?
2. Future expansion plans — any additional loads beyond the 50 kW reserve?
3. Backup/resilience requirements — is the optional 2.8-hour BESS backup sufficient, or is a generator needed?
4. Budget priorities — phase the PV and BESS installation, or build all at once?