Annual Solar Panel Maintenance Checklist

Solar panels need very little maintenance, but an annual check keeps your system performing well and catches problems early. Here's a practical checklist you can run through in 30 minutes.

The Annual Checklist

1. Visual Inspection (From the Ground)

What to look for:

• Panel surface: Any visible cracks, chips, or discolouration? Use binoculars if panels are high up.
• Bird mess or debris: Heavy soiling, leaves, or nesting material visible?
• Mounting brackets: Any visible movement, rust, or looseness?
• Cable condition: Visible cables intact and secured? No hanging or exposed wires?
• Roof condition: Any damaged tiles around the panel mounting points?

When to do it: Spring (March–April), after winter storms and before peak generation season.

2. Inverter Check

The inverter is the most likely component to develop issues. Check:

• Power light: Is the inverter showing a green/normal status light during daylight?
• Error codes: Any fault codes or warning indicators on the display?
• Fan noise: Does the inverter fan sound normal? Unusual rattling or grinding suggests bearing wear.
• Temperature: Is the inverter excessively hot to the touch? (Warm is normal; too hot to hold your hand near is not.)
• Display readout: Does the real-time generation figure look reasonable for the conditions?

When to do it: Any sunny day — check that the inverter is actively generating.

3. Generation Review

Compare this year's generation against previous years and expected output:

• Annual total: Within 10% of previous years? (Weather variation is normal; 20%+ decline suggests a problem.)
• Monthly pattern: Does the seasonal curve look normal? A flat month that should be productive is a red flag.
• Compare against neighbours: If you know other local solar owners, are they seeing similar output?

How to check: Your inverter app or generation meter readings. See our reading your generation meter guide.

4. Electrical Safety

• DC isolator: Located near the panels on the roof or external wall. Check it's not damaged, leaking, or showing signs of water ingress. (DC isolator failure is a known issue — discolouration or melting around the switch is a serious safety concern.)
• AC isolator: Located near the inverter or consumer unit. Should be in the ON position and undamaged.
• Consumer unit: No tripped breakers related to the solar circuit?

5. Battery Check (If Applicable)

• Battery status: Showing normal state of charge and cycling?
• Error codes: Any warnings in the battery management system?
• Physical condition: No swelling, leaking, or unusual odours?
• Temperature: Battery within normal operating range?
• Cycle count: How many cycles has the battery completed? (Available in most battery apps.)

6. Export Meter / Smart Meter

• Export recording: Is your smart meter still recording export correctly?
• SEG payments: Are you receiving regular SEG payments?
• Generation meter: Take a reading and record it.

Seasonal Considerations

Spring (March–April)

• Best time for the annual visual inspection
• Clean panels if needed (after pollen season, before summer generation peak)
• Check for winter storm damage

Summer (June–August)

• Monitor generation — this is when your system should perform best
• If output is unexpectedly low, investigate (shading from new tree growth, panel soiling)

Autumn (October–November)

• Clear leaves from panels and gutters near panels
• Check for bird nesting material accumulated during summer

Winter (December–February)

• Minimal maintenance needed
• Check inverter is still functioning (it should generate something even on short days)
• Snow will slide off tilted panels naturally — don't try to clear it

When to Call a Professional

Most annual maintenance is DIY. Call a professional for:

• Inverter error codes you can't resolve by restarting
• Significant generation decline (20%+ below expected) with no obvious cause
• Physical damage to panels, wiring, or mounting
• DC isolator concerns — any discolouration or damage
• Roof leaks around panel mounting points
• Battery warnings that persist after restart

A professional inspection/service typically costs £100–£200 and includes checking connections, testing output, and identifying issues you can't see from the ground.

Maintenance Costs

Realistic annual budget: £50–£100/year averaged over the system's life, including the eventual inverter replacement. Many years will cost nothing.

The 5-Minute Monthly Check

Don't want to wait for the annual inspection? A quick monthly routine:

1. Open your inverter app
2. Check this month's generation against the same month last year
3. Look for any error notifications
4. Glance at the panels from the ground — anything obviously wrong?

This 5-minute habit catches 90% of problems before they become expensive. Combined with an annual deeper check, your solar system should run trouble-free for decades.

For more on what affects your panel lifespan, see our panel lifespan guide. For cleaning specifics, see our cleaning guide.

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