Solar panels rarely produce the same amount of electricity every day. Sunlight, temperature, season, and household energy use all affect what you see on your monitoring app or electric bill. But a sustained drop below your system’s usual production can point to a problem worth investigating. Start by comparing output under similar conditions, then check for shading, surface buildup, equipment alerts, and changes in system settings. These practical checks can help narrow down the cause without risking an electrical injury.
Compare Output Fairly
Check production against the same period in previous months or years, if your monitoring system provides that history. A cloudy day, shorter winter daylight, snow cover, or unusually hot weather can lower output without indicating a fault. Compare similar seasons and account for recent weather before treating a single low reading as a system failure.
Also distinguish electricity produced from electricity used. Your utility bill reflects consumption, solar production, and how your utility credits or measures exported power. A higher bill does not necessarily mean the panels are producing less. Review the inverter or monitoring app’s production data, and note when the decline began.
Check Shade and Soiling
New shade can reduce production even when it covers only part of an array. Tree growth, a new building, a chimney, or equipment on the roof may block sunlight at certain hours. Compare the affected times with the system’s production curve. If output falls sharply when a shadow crosses the panels, ask a qualified professional about safe trimming or system-level options.
Dust, pollen, leaves, and bird droppings can also limit the light reaching panel surfaces. Snow and ice may cover all or part of an array. Look from the ground for visible buildup, but do not climb onto the roof or scrape panels. Follow the manufacturer’s cleaning guidance; when cleaning is needed, use a qualified service provider to avoid falls and panel damage.
Look for Equipment Alerts
An inverter converts panel electricity into power your home can use. If it shuts down, operates intermittently, or displays a fault code, production may fall or stop. Check the inverter display and monitoring app for alerts, and record the exact message. Some systems also have a communications issue that interrupts monitoring even while the equipment continues to operate, so confirm whether the problem is missing data or genuinely low production.
Wiring faults, loose connections, damaged conduit, or a failed panel component can interrupt part or all of an array. These issues are not safe to diagnose by opening electrical equipment or touching exposed wires. Watch for visible damage, burning smells, unusual sounds, or repeated breaker trips. If you notice a safety warning or damaged equipment, keep clear and contact a licensed solar technician.
Review Settings and Get Help
A monitoring app may show low output after a network change, account update, or communication gateway failure. Check whether the app is online and whether the displayed date range and units are correct. Avoid resetting breakers or changing inverter settings unless the system instructions specifically direct you to do so; an incorrect change can complicate troubleshooting or interrupt operation.
When contacting a technician, share the system’s recent production readings, alert codes, the date the decline began, and any visible changes around the panels. Mention recent roof work, electrical work, tree trimming, or severe weather. A technician can compare measured output with expected performance and inspect the inverter, wiring, and array safely. Casco Bay Solar Repair serves Portland, Maine, and can help assess a suspected system fault.
A production dip may reflect normal weather and seasonal changes, but persistent low readings, inverter alerts, or visible damage deserve attention. Compare like periods, record what you observe, and avoid roof or electrical work yourself. If the cause remains unclear, contact a qualified solar repair technician to inspect the system and recommend safe next steps.