Let me tell you about my buddy Jack who learned the hard way that you should always turn off solar panels before cleaning them. Jack installed some slick new solar panels on his roof last year to save money on electricity. After a few months, he noticed they were looking pretty dusty and grimy.
“No problem,” Jack thought, “I’ll just grab the garden hose and spray these babies down.” Without thinking twice, he climbed up on the roof with the hose and started spraying. Within seconds, ZAP! He got lit up like a Christmas tree from the live electrical current still flowing through the solar cells. Luckily he didn’t get seriously injured, but he sure learned an important lesson about safety that day.
When Should You Clean Those Solar Panels Anyway?
So when do solar panels actually need cleaning, and when can you rely on good ol’ Mother Nature to take care of the job? There are a few situations that typically necessitate hauling out the cleaning supplies:
Breathing in the Haze
If you live in an area with significant air pollution like factory smoke or vehicle exhaust, dust and grime will build up faster on your solar panels. Smoggy cities or places downwind from power plants may need those panels scrubbed a little more often.
At the Beach
Sandy areas near the ocean or even large lakes are prone to salt, sand, and seashell deposits landing on solar panels. Over time this can really cut into the solar cells’ efficiency.
High and Dry
Folks in arid, desert climates or drought-stricken regions won’t see enough heavy rain to keep solar panels pristine. Dry airborne dust is a solar panel’s worst enemy!
In the springtime tree pollen spreads far and wide, coating everything in a gross yellow film. Solar panels are no exception. Pollen buildup blocks the sun’s rays from hitting those solar cells.
Major construction projects kick up all kinds of debris like dirt, gravel, wood, and metal shards. Solar panels in the vicinity will need a bath to keep performing well.
Rain Rain Don’t Go Away
While raindrops do self-clean solar panels to some degree, they can’t remove all the grime. If rainfall in your area is infrequent or very light, you’ll need to pick up the slack manually.
Why Bother Cleaning Solar Panels Anyway?
Other than just making your roof look pretty again, keeping your solar panels squeaky clean provides some great benefits:
- Clean solar panels generate up to 21% more electricity than dirty ones according to energy experts. All that dust and gunk blocks sunshine from reaching the solar cells, hampering their photon-converting abilities.
- Many solar panel warranties require you to clean the panels regularly. Skipping cleanings could void that 20-year warranty you paid good money for. Read the fine print!
- Accumulated grime, bird poop, pollen and the like can permanently damage solar cells over time, shortening their lifespan. A long-lasting solar system needs occasional scrub downs.
- Spotless solar panels just plain look nicer on your roof than disgusting ones caked with blackened guano. Don’t be that house!
- Cleaning solar panels gives you an opportunity to inspect for any cracks, leaks or rodent damage. It’s much easier to spot issues on a sparkling clean solar panel.
Is Cleaning Solar Panels Safe?
Here’s where Jack made his nearly-fatal mistake. Solar panels are complex electrical systems, not just inert slabs of glass and metal. The sun’s photons excite electrons in the solar cells, generating electrical current. If water comes into contact with a live electrical source…ZAP!
Thankfully, Mother Nature lends a hand – rainwater can cleanse dust and debris off solar panels safely about 95% of the time. But for the deep cleans required periodically, you’ll want to take safety seriously.
Don’t Go Chasing Waterfalls
The safest way to clean solar panels is ensuring they are NOT producing any electrical current. Completely powering down the solar panel system prevents any wet + electricity encounters that could ruin your day.
Let’s Do This: How to Clean Solar Panels Safely
Now that we’ve covered the basics, let’s get into the nitty gritty details of safely cleaning solar panels:
Consult Thy Manual
Every solar panel system is unique, so begin by reading the manufacturer’s cleaning recommendations. Follow their specific steps for safely shutting down the system before getting started.
Once the system is “off”, take a voltmeter to the solar cells to double-check for any lingering electrical flow before anything gets wet. Better safe than sorry.
Cut the Power at the Source
When shutting down the solar panels, don’t just flip the inverter switch – make sure to cut power generation fully at the main electrical junction. Inverters don’t stop the solar cells from outputting energy.
Look But Don’t Touch
Never touch the electrical backside of solar panels where all the wiring lives. Clean only the topside glass surface where the sunlight hits.
Before any liquids touch the panels, do an initial dry debris removal. Use a soft brush to dislodge dust, leaves, seeds, pollen, gravel, bird poop, etc.
suds and Sprays
Next comes the real cleaning. Use a mild soap and water solution and soft microfiber cloths or non-abrasive sponges. Garden hose sprayers on a low setting also work well if you remain cautious.
Stand safely with both feet on roof rafters, not on the solar panels themselves. The glass surface can get slippery. Also don’t walk across the middle of panels to avoid cracking.
Clean panels in the evening or early morning when they aren’t hot to the touch. Heat accelerates chemical reactions so avoid mid-day solar cell baths.
Make sure panels are completely dry before restoring power to the system. Water conducts electricity, so any dampness left behind spells trouble. Give ’em time to air dry thoroughly.
Inspect for any cracks, corrosion, dents or rodent damage while cleaning. Solar panels take abuse from weather and wildlife. Catch issues early before they ruin efficiency.
Call the Pros
If the solar panels are especially large, tall or numerous, consider hiring a professional cleaning service. They have specialized equipment to safely clean without injury or falls.
Dangers of Cleaning Live Solar Panels
Now that you know how to clean panels safely with the power off, let’s also examine the risks of cleaning energized solar panels to drive home the safety message:
Direct Current Dangers
Solar panels produce DC power, not AC. With alternating current, a shock forces muscles to contract and let go. But DC current causes sustained involuntary muscle contractions.
If the solar system isn’t properly grounded, touching the live panels can complete a circuit through your body down into the earth resulting in an excruciating shock.
Electrical arcing from damaged wires or rodent chew-throughs can create shock hazards. Once arcing starts, DC current just keeps on flowing.
Cracked solar cells leaking rainwater combined with DC current pumping through the system is a dangerous mix resulting in potential electrocution.
Hurts So Bad
DC electrical shock can cause cardiac arrest, severe burns, blunt force trauma from falls, and serious neurological damage. Prevention is key for safe solar panel cleaning.
How Often Should You Clean Solar Panels?
We’ve covered all the why’s and how’s of solar panel cleaning, but just how frequently does this need to be done?
Occasional Rain Not Enough
While a little rainwater helps self-clean solar panels, it can’t remove all the grime that builds up from environmental factors. Supplemental manual cleaning helps.
How often you should clean solar panels depends on the dust, pollen, pollution, rainfall and other climate conditions in your specific area. More extreme environments need more frequent cleanings.
For homes surrounded by lots of trees and vegetation that drop leaves, seeds, sap and pollen on solar panels, aim to clean about twice per year.
Gritty Urban Jungles
In cities with heavy air pollution, construction dust and other grimy environmental factors, bump up cleaning to 3-4 times per year.
Hire Some Help
Many solar panel cleaning services offer periodic cleaning packages on a monthly, quarterly or biannual basis. Choose the frequency that fits your climate and budget.
Parting Thoughts on Solar Panel Cleaning
Hopefully this guide has illuminated the ins and outs of safely cleaning solar panels. The key takeaways are:
- Turn OFF all power generation at the source before wet cleaning
- Allow time for panels to fully dry before reactivating the system
- Clean gently to avoid scratches or cracks
- Inspect closely for any damage during cleanings
- Increase cleaning frequency based on environmental conditions
- Consider hiring pros for difficult rooftop access or large systems
Follow these rules, and you’ll avoid any shocking cleaning experiences. Your solar panels will reward you with decades of optimal sunlight-to-electricity conversion. Just take it from my pal Jack who learned about solar panel safety the hard way – don’t be like Jack!
So grab your shammy cloth, scrub brush, and garden hose and get those solar cells squeaky clean. Your roof, wallet, and nervous system will thank you.