Yes, solar panels require regular cleaning even after installation. If not cleaned, solar panels can experience up to 30% energy yield loss per year, especially in dusty, polluted, or low-rainfall areas. While rain can help clean panels, it is not always sufficient to maintain optimal efficiency.
Why Cleaning Solar Panels Is Necessary After Installation
Solar panels work by absorbing sunlight through photovoltaic (PV) cells. When dust, dirt, grime, or bird droppings accumulate on the panel surface, sunlight is partially blocked, directly reducing electricity generation and overall system performance.
What Happens If Solar Panels Are Not Cleaned?
- Reduced energy output
- Lower system efficiency
- Delayed return on investment (ROI)
- Increased risk of permanent stains
- Blockage of lower PV cell rows after rainfall
Does Dust Really Reduce Solar Panel Efficiency?
Yes. Even a thin layer of dust can significantly reduce sunlight absorption and power generation.
How Much Energy Loss Can Occur Without Cleaning?
Solar panels can lose up to 30% of their energy output annually if they are not cleaned at least once a month.
The actual loss depends on:
- Dust intensity in the region
- Nearby pollution sources
- Wind patterns
- Frequency of rainfall
- Panel tilt angle
Can Rain Clean Solar Panels on Its Own?
When Rain Is Enough
Rainfall can help clean solar panels if:
- Panels are tilted (not installed completely flat)
- Rainfall is frequent
- Dust levels are low
When Rain Is Not Enough
Manual cleaning becomes essential when:
- Panels are near factories, highways, or farms
- Wind frequently blows dust onto the panels
- You live in a low-rainfall region
- Dirt settles along the bottom edge of panels
Rain can clean solar panels partially, but it usually does not remove stubborn dirt or bird droppings.
A Smarter Alternative: Self-Cleaning Rooftop Solar Systems by Freyr Energy
To reduce manual effort and ensure consistent performance, Freyr Energy offers Self-Cleaning Rooftop Solar Systems. These systems use automated sprinklers that periodically clean the solar panels, helping:
- Maintain optimal efficiency
- Prevent long-term dust buildup
- Boost energy output consistently
- Reduce the need for frequent manual cleaning
Self-cleaning systems are especially beneficial in high-dust and low-rainfall regions, where manual cleaning would otherwise be required more often.
How Often Should Solar Panels Be Cleaned in India?
Recommended Cleaning Frequency: Avoid excessive cleaning. Weekly cleaning is only required in regions with extremely high dust accumulation.
Recommended Cleaning Frequency:
|
Location & Conditions |
Cleaning Frequency |
|
High dust / pollution areas |
Every 2–4 weeks |
|
Normal residential areas |
Once a month |
|
Soap-based cleaning |
Once every 6 months |
|
Bird droppings present |
Immediately |
How to Clean Solar Panels on Roof in India (Step-by-Step)
Step 1: Shut Down the Solar System
Before cleaning, turn off the solar system completely as per the shutdown procedure mentioned in the user handbook.
Step 2: Use the Right Water Temperature
- Use room-temperature water only
- Do not use warm or hot water
- Avoid directing water to the back of the panels or beneath mounting structures
Step 3: Gentle Cleaning Method
- Use a soft cloth or sponge
- Mild dish soap can be used for stubborn dirt
- Avoid detergents and abrasive powders
Step 4: Rinse Safely
- Use a garden hose or bucket
- Do not use high-pressure water sprayers
- Pressure above 35 bar can damage solar panels
What Is the Safest Way to Clean Rooftop Solar Panels?
Use soft water, a sponge, and gentle soap without pressure.
Best Tools for Solar Panel Cleaning
Safe Cleaning Tools
- Soft sponge
- Microfiber cloth
- Garden hose
- Mild dishwashing soap
Tools to Avoid
- High-pressure washers
- Hard or metal brushes
- Laundry detergents
- Chemical or abrasive cleaners
Getting Rid of Tough Stains on Solar Panels
How to Remove Bird Droppings and Hardened Dirt
Rain or plain water may not remove hardened stains like bird droppings. In such cases:
- Use a soft brush with no harsh bristles
- Lightly scrub with mild dish soap
- Rinse thoroughly with clean water
In nearly 99% of cases, plain water is sufficient for cleaning solar panels.
Best Time to Clean Solar Panels
Ideal Conditions
- Early morning (best time)
- Cloudy days
- Cool evenings
Why Timing Matters
- Hot glass combined with cold water can cause cracks
- Soap dries quickly in direct sunlight, leaving residue
- Morning dew softens dirt, reducing cleaning effort
Solar Panel Cleaning Safety Checklist
- Solar system switched off
- Soft sponge or cloth used
- Mild soap only (optional)
- Low-pressure water
- Cleaning done during cool hours
- No abrasive chemicals
- No pressure washers
Common Solar Panel Cleaning Mistakes to Avoid
- Cleaning panels during peak sunlight
- Using high-pressure water
- Ignoring bird droppings
- Overcleaning unnecessarily
- Using chemical detergents
Pro Tip: Whether you choose manual cleaning or an automated self-cleaning system, regular maintenance is key to maximising your solar investment and ensuring long-term energy savings.