diff --git a/docs/lab-004-solar-deployment.md b/docs/lab-004-solar-deployment.md new file mode 100644 index 0000000..c36b891 --- /dev/null +++ b/docs/lab-004-solar-deployment.md @@ -0,0 +1,150 @@ +# LAB-004: 600W Solar Array Deployment Guide + +> Issue #529 | Cabin Compute Lab Power System +> Budget: $200-500 + +## System Overview + +4x 150W panels → MPPT controller → 12V battery bank → 1000W inverter → 120V AC + +``` +[PANELS 4x150W] ──series/parallel──► [MPPT 30A] ──► [BATTERY BANK 4x12V] + │ + [1000W INVERTER] + │ + [120V AC OUTLETS] +``` + +## Wiring Configuration + +**Panels:** 2S2P (two in series, two strings in parallel) +- Series pair: 18V + 18V = 36V at 8.3A +- Parallel strings: 36V at 16.6A total +- Total: ~600W at 36V DC + +**Battery bank:** 4x 12V in parallel +- Voltage: 12V (stays 12V) +- Capacity: sum of all 4 batteries (e.g., 4x 100Ah = 400Ah) +- Usable: ~200Ah (50% depth of discharge for longevity) + +## Parts List + +| Item | Spec | Est. Cost | +|------|------|-----------| +| MPPT Charge Controller | 30A minimum, 12V/24V, 100V input | $60-100 | +| Pure Sine Wave Inverter | 1000W continuous, 12V input | $80-120 | +| MC4 Connectors | 4 pairs (Y-connectors for parallel) | $15-20 | +| 10AWG PV Wire | 50ft (panels to controller) | $25-35 | +| 6AWG Battery Wire | 10ft (bank to inverter) | $15-20 | +| Inline Fuse | 30A between controller and batteries | $10 | +| Fuse/Breaker | 100A between batteries and inverter | $15-20 | +| Battery Cables | 4/0 AWG, 1ft jumpers for parallel | $20-30 | +| Extension Cord | 12-gauge, 50ft (inverter to desk) | $20-30 | +| Kill-A-Watt Meter | Verify clean AC output | $25 | +| **Total** | | **$285-405** | + +## Wiring Diagram + +``` + ┌──────────────────────────────┐ + │ SOLAR PANELS │ + │ ┌──────┐ ┌──────┐ │ + │ │ 150W │──+──│ 150W │ │ String 1 (36V) + │ └──────┘ │ └──────┘ │ + │ │ │ + │ ┌──────┐ │ ┌──────┐ │ + │ │ 150W │──+──│ 150W │ │ String 2 (36V) + │ └──────┘ └──────┘ │ + └──────────┬───────────────────┘ + │ PV+ PV- + │ 10AWG + ┌──────────▼───────────────────┐ + │ MPPT CONTROLLER │ + │ 30A, 12V/24V │ + │ PV INPUT ──── BATTERY OUTPUT │ + └──────────┬───────────────────┘ + │ BAT+ BAT- + │ 6AWG + 30A fuse + ┌──────────▼───────────────────┐ + │ BATTERY BANK │ + │ ┌──────┐ ┌──────┐ │ + │ │ 12V │═│ 12V │ (parallel)│ + │ └──────┘ └──────┘ │ + │ ┌──────┐ ┌──────┐ │ + │ │ 12V │═│ 12V │ (parallel)│ + │ └──────┘ └──────┘ │ + └──────────┬───────────────────┘ + │ 4/0 AWG + 100A breaker + ┌──────────▼───────────────────┐ + │ 1000W INVERTER │ + │ 12V DC ──── 120V AC │ + └──────────┬───────────────────┘ + │ 12-gauge extension + ┌──────────▼───────────────────┐ + │ AC OUTLETS │ + │ Desk │ Coffee Table │ Spare │ + └──────────────────────────────┘ +``` + +## Installation Checklist + +### Pre-Installation +- [ ] Verify panel specs (Voc, Isc, Vmp, Imp) match wiring plan +- [ ] Test each panel individually with multimeter (should read ~18V open circuit) +- [ ] Verify battery bank voltage (12.4V+ for charged batteries) +- [ ] Clear panel mounting area of snow/shade/debris + +### Wiring Order (safety: work from panels down) +1. [ ] Mount panels or secure in optimal sun position (south-facing, 30-45° tilt) +2. [ ] Connect panel strings in series (+ to -) with MC4 connectors +3. [ ] Connect string outputs in parallel with Y-connectors (PV+ and PV-) +4. [ ] Run 10AWG PV wire from panels to controller location +5. [ ] Connect PV wires to MPPT controller PV input +6. [ ] Connect battery bank to controller battery output (with 30A fuse) +7. [ ] Connect inverter to battery bank (with 100A breaker) +8. [ ] Run 12-gauge extension cord from inverter to desk zone + +### Battery Bank Wiring +- [ ] Wire 4 batteries in parallel: all + together, all - together +- [ ] Use 4/0 AWG cables for jumpers (short as possible) +- [ ] Connect load/controller to diagonally opposite terminals (balances charge/discharge) +- [ ] Torque all connections to spec + +### Testing +- [ ] Verify controller shows PV input voltage (should be ~36V in sun) +- [ ] Verify controller shows battery charging current +- [ ] Verify inverter powers on without load +- [ ] Test with single laptop first +- [ ] Monitor for 1 hour: check for hot connections, smells, unusual sounds +- [ ] Run Kill-A-Watt on inverter output to verify clean 120V AC +- [ ] 48-hour stability test: leave system running under normal load + +### Documentation +- [ ] Photo of wiring diagram on site +- [ ] Photo of installed panels +- [ ] Photo of battery bank and connections +- [ ] Photo of controller display showing charge status +- [ ] Upload all photos to issue #529 + +## Safety Notes + +1. **Always disconnect panels before working on wiring** — panels produce voltage in any light +2. **Fuse everything** — 30A between controller and batteries, 100A between batteries and inverter +3. **Vent batteries** — if using lead-acid, ensure adequate ventilation for hydrogen gas +4. **Check polarity twice** — reverse polarity WILL damage controller and inverter +5. **Secure all connections** — loose connections cause arcing and fire +6. **Keep batteries off concrete** — use plywood or plastic battery tray +7. **No Bitcoin miners on base load** — explicitly out of scope + +## Estimated Runtime + +With 600W panels and 400Ah battery bank at 50% DoD: +- 200Ah × 12V = 2,400Wh usable +- Laptop + monitor + accessories: ~100W +- **Runtime on batteries alone: ~24 hours** +- With daytime solar charging: essentially unlimited during sun hours +- Cloudy days: expect 4-6 hours of reduced charging + +--- + +*Generated for issue #529 | LAB-004*