When Is the Best Time to Clean Your Solar Panels in Fresno?

If you're like most Fresno homeowners, you probably assume your solar panels are “set it and forget it.” After all, they’re built to last 25+ years — right?

While that’s true, solar panels need regular cleaning to maintain peak performance. And knowing when to clean them can make all the difference in how much power your system produces — and how much money you save.

In this blog, we’ll cover:

• The ideal cleaning schedule for Fresno’s climate

• Seasonal cleaning recommendations

• Signs it’s time to clean your panels

• Why timing matters more under California’s NEM 3.0

• And how professional cleaning protects your investment

☀️ Why Clean Panels = More Power

Solar panels work by converting sunlight into electricity. But dirt, dust, pollen, bird droppings, and wildfire ash block the sun’s rays, reducing energy output — often by 15–25% or more.

That’s money lost.

In fact, many homeowners don’t realize their system is underperforming until their PG&E bill goes up — and by then, it’s been weeks (or months) of lost production.

📍 What Makes Fresno Unique

Fresno’s weather conditions mean solar panels here get dirtier, faster:

• Dry climate: Minimal rainfall means dust and debris don’t get rinsed away naturally.

• Agricultural activity: Pollen, fertilizer particles, and valley dust settle on panels year-round.

• Bird activity: Fresno’s rooftops are popular landing zones — especially for pigeons.

• Wildfire ash (seasonal): Even distant fires leave residue that coats panels.

If you haven’t cleaned your panels in 6+ months, you’re almost certainly losing power.

🧭 When to Clean Solar Panels in Fresno

Here’s a breakdown of when to clean based on seasonal patterns:

🧼 1. Spring (February – April)

Why:

• Pollen levels are high

• Tree sap starts accumulating

• Mild weather = ideal cleaning conditions

✅ Best time for your first yearly cleaning
✅ Removes winter grime and preps panels for peak summer production

🧼 2. Late Summer / Early Fall (August – October)

Why:

• Peak dust buildup from dry heat

• Ash from wildfire season

• Bug residue and bird droppings increase

✅ This is often the dirtiest time of year for solar panels
✅ Cleaning now restores your system before PG&E’s highest rate season

🧼 3. Optional: After Major Events

There are some cases where immediate cleaning is necessary, regardless of the month:

• Wildfire ash coating

• Heavy bird activity

• Visible drop in output on your inverter or app

• Recent construction or roof work nearby

OneSun Solutions offers on-demand solar cleanings for these exact situations.

🧪 NEM 3.0 Makes Cleaning Even More Important

Under California’s new NEM 3.0 rules, most solar users now earn less money for excess energy sent back to the grid. That means your savings depend more on how much solar energy you use directly in your home.

Dirty panels = less production = more power pulled from PG&E = less savings.

Keeping your panels clean helps maximize your self-consumption rate — which is now more valuable than ever.

🔍 Signs It’s Time to Clean Your Panels

Still not sure if it’s time? Watch for:

• Higher PG&E bills than usual

• Visible dirt, bird droppings, or dust layers on the panels

• Drop in kWh production reported by your solar monitoring app

• Time passed: More than 6 months since your last cleaning

We recommend setting calendar reminders every 6 months or signing up for a cleaning plan so you never forget.

🧽 DIY vs. Professional Cleaning

While you can rinse panels yourself, there are risks:

🚫 Climbing on a roof is dangerous
🚫 Using tap water can leave mineral deposits
🚫 Scrubbing with the wrong tool can damage panel surfaces
🚫 DIY jobs may void your warranty

At One Sun Solutions, we use:

• Soft-bristle brushes

• Deionized water

• Roof-safe safety protocols

• Trained technicians

• Optional before/after performance checks

🛠️ What Happens During a Cleaning?

Our solar panel cleaning service includes:

• Visual inspection of all panels

• Removal of dust, bird droppings, sap, and debris

• Spot-free rinse

• Inverter check (on request)

• Reporting of any damage, cracks, or performance concerns

We also clean ground-mounted systems, carports, and commercial panels.

💰 How Much Does It Cost?

Our pricing is affordable and transparent:

• Flat rates for most single-story homes

• Custom quotes for large or multi-level homes

• Maintenance plans for biannual or quarterly cleaning

• Discounts for solar + roof inspection combo

And yes — we serve all of Fresno, Clovis, Madera, and the surrounding Central Valley.

✅ Final Word: Clean Panels, Maximum Power

Dirty panels = lower output = less savings.

By cleaning your solar panels twice a year, especially during spring and late summer, you’ll protect your system and keep your utility bills as low as possible.

👉 Book your solar panel cleaning today with One Sun Solutions — Fresno’s trusted local solar maintenance experts.