Residential Solar — Maintenance & Troubleshooting

Maintenance & Troubleshooting¶

A solar system that works well on day one should still work well in year ten — if you maintain it. The good news: a Philippine setup requires very little active effort. The bad news: the things you do need to do are easy to forget.

Cleaning¶

Rain handles most of the cleaning for you. The Philippines gets enough rainfall that panels rarely accumulate serious grime between storms. For most setups, manual cleaning 2-4 times per year is sufficient — a soft brush and plain water to remove bird droppings, heavy dust, or anything else rain didn't dislodge.

A few rules:

Never use a pressure washer. The high-pressure jet damages the anti-reflective coating on panel glass, permanently reducing light transmission.
Clean in the early morning when panels are still cool. Spraying cold water onto hot panels mid-afternoon causes thermal shock and micro-cracks in the glass or cell substrate over time.
No soap or chemical cleaners. Water is enough. Detergent residue attracts more dirt and can leave streaks that reduce output.

Monitoring via Home Assistant¶

Passive monitoring through Home Assistant is where you recover production losses before they compound. Set up alerts for production drops: if your actual output falls more than 15% below the Forecast.Solar prediction for three or more consecutive days, investigate.

Common causes to check in order:

Dirty panels (most likely after a dry spell)
New shade sources — a tree branch that grew into your array's sightline
Inverter thermal derating — some inverters throttle output above 40-45°C ambient. Check inverter temperature sensors if exposed.
Panel or string fault — HA should surface any inverter error codes via notification automations

Track monthly and yearly production totals using HA's Energy Dashboard long-term statistics. A gradual year-over-year decline of 0.5-0.7% is normal panel degradation. A sudden drop of 5%+ warrants inspection.

Battery Health¶

LFP (lithium iron phosphate) batteries are the dominant chemistry for home solar in the Philippines and they are genuinely long-lived — rated for 6,000+ cycles at 80% depth of discharge, which works out to roughly 16 years of daily cycling. But that rated lifespan assumes you treat them correctly.

Key practices:

Avoid deep discharge below 20% SOC (State of Charge — how "full" the battery is, like a fuel gauge). Most inverters let you set a discharge floor. Set it and leave it.
Monitor charge/discharge curves in HA. A healthy battery charges and discharges at a consistent voltage profile. Sudden capacity drops — the battery "full" indicator triggering at an unusually low watt-hour count — are the first sign of cell degradation.
Keep batteries ventilated and below 45°C. Heat accelerates electrolyte breakdown. Enclosed battery rooms need airflow, especially during charging when cells generate heat.
BMS communication matters. Your inverter should be reading SOC from the battery's BMS (Battery Management System — a built-in circuit board that monitors and protects the battery), not estimating from voltage alone. Verify this in the inverter settings.

Common Issues¶

Symptom	Likely Cause	Fix
Production lower than expected	Shade, dirty panels, inverter derating in heat	Clean panels, check for new shade sources, verify inverter isn't thermal throttling
Battery not charging fully	Wrong charge voltage setting, BMS communication error	Check inverter battery profile settings, verify BMS communication cable is seated
HA integration disconnecting	Firmware mismatch, network issues, Modbus timeout	Update inverter firmware, check network stability, increase Modbus timeout in HA config
Grid export but bill increased	No net metering / no zero-export limiter active	Apply for net metering or install zero-export limiter immediately
Inverter showing fault codes	Various — grid voltage or frequency out of range	Check inverter manual; most Philippine faults are grid-side (MERALCO voltage fluctuation is common)

Annual Maintenance¶

If you signed a maintenance contract with your installer, expect to pay ₱3,000–6,000/year for an annual visit that covers panel cleaning, connection inspection, and a system health report. Worth it for the first year or two while you're still learning your system.

DIY annual checklist:

Inspect all exposed wiring and conduit (protective tubing that wires run through) for UV degradation or pest damage
Check mounting rail bolts — typhoon winds work fasteners loose over time
Clean panels if not recently rained
Verify all grounding connections are secure and rust-free
Check DC isolator (emergency shutdown switch for the solar panels) and AC breaker operation
Log inverter lifetime kWh and compare to prior year for degradation tracking

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