Executive Overview
Operating an off-grid processing apiary in western Puerto Rico presents dual challenges: intense solar insolation coupled with high tropical ambient humidity (averaging 78%–88% RH in Mayagüez) and frequent island grid instability. The BuenoBee Solar Microgrid provides uninterrupted, zero-emission electrical power for industrial honey uncapping, centrifugal extraction, low-temperature curing, and telemetry collection.
This document details the complete electrical architecture, component specifications, single-line power routing, and load-shedding automation.
1. System Specifications & Balance of System (BoS)
| Component | Technical Specification | Operational Target |
|---|---|---|
| PV Generation | 24x 350W Bifacial Monocrystalline Panels (8.4 kWp) | 38.6 kWh avg. daily yield |
| Array Geometry | 2 strings of 12 modules in series (Voc: 492V, Isc: 10.8A) | Ground clearance: 1.2m above grade |
| Charge Controllers | Dual 150V / 60A Ultra-Fast MPPT controllers | 99.2% tracking efficiency |
| Energy Storage | 4x 48V 100Ah LiFePO4 (20.48 kWh gross capacity) | 80% max DoD (16.38 kWh usable) |
| Inverter System | 8.0 kW Split-Phase Pure Sine Wave (120/240Vac) | THD < 2.5%, surge 16 kW (5s) |
| System Voltage | 48Vdc nominal (operating range: 44.8V – 56.4V) | Floating charge: 54.4Vdc |
2. Electrical Single-Line Architecture
The system segregates power distribution into two electrical distribution buses to safeguard extraction equipment from brownouts and transient surges:
[PV Array: 8.4 kWp]
│ (DC Disconnect 600V / 30A + SPD Type 1)
▼
[Dual MPPT Hybrid Inverter: 8 kW Split-Phase] ───◄►─── [48V 400Ah LiFePO4 Bank]
│
├──► [Sub-Panel A: Critical Life & Extraction (Zero-Break UPS)]
│ ├── Centrifugal Honey Extractor (1.5 HP VFD motor)
│ ├── Solar Room Humidity Dehumidifier (450W continuous)
│ └── LoRaWAN Gateway & IoT Telemetry Server (25W)
│
└──► [Sub-Panel B: Auxiliary Sheddable Loads (SoC > 35%)]
├── Solar Wax Clarifier Bath (1200W resistive)
├── Workshop LED High-Bays (180W)
└── EV Farm Cart Charging Station (1600W daytime only)3. Automated Load-Shedding & Battery Management
To protect battery cell longevity in prolonged tropical cloud cover, the supervisory control system enforces an automated three-tier load governance policy:
interface BatteryGovernorState {
stateOfChargePercent: number;
dcVoltage: number;
activeTier: 1 | 2 | 3;
}
export function evaluateLoadShedding(state: BatteryGovernorState): string[] {
const { stateOfChargePercent } = state;
if (stateOfChargePercent >= 50) {
// Normal Operations: All circuits fully energized
return ['Sub-Panel-A', 'Sub-Panel-B-WaxMelter', 'Sub-Panel-B-EVCharging'];
} else if (stateOfChargePercent >= 35) {
// Tier 1 Shed: Shed high-draw thermal and vehicle loads
return ['Sub-Panel-A', 'Sub-Panel-B-WorkshopLighting'];
} else {
// Tier 2 Emergency: Preserve solely extraction ventilation & IoT heartbeat
return ['Sub-Panel-A-Ventilation', 'Sub-Panel-A-TelemetryGateway'];
}
}4. Hurricane Hardening & Galvanic Grounding Checklist
- Ground Anchor Racking: Helical ground screws driven 1.8 meters into bedrock, rated for 155 mph sustained Category 4 wind gusts.
- Corrosion Mitigation: All brackets and fasteners specified in 316 Marine-Grade Stainless Steel to resist Caribbean salt-spray atmospheric oxidation.
- Isolated Earth Ground: Dedicated copper-clad ground rod network maintaining ground loop resistance below 4.2 Ohms.
- Dual Lightning Arrestors: Dual-stage Class I+II Surge Protection Devices installed on both positive and negative DC conductors prior to inverter entry.