Covering solar panels sounds straightforward, but the safety reality comes first: solar panels generate DC voltage whenever light hits them, even through a cover. A standard 400 W panel produces 30 - 45 volts open-circuit in daylight. That's enough for a serious shock or arc flash if you handle the system wrong. So any covering process starts with the electrical risk, not just physical protection.
Honestly, the cheap-tarp approach causes more "I thought it was safe" injuries than the industry likes to admit. My take? Spend the $30 on purpose-made covers and pull the disconnect first. Saving $20 is a bad trade if you brush a live DC string.
When Should You Temporarily Cover Solar Panels?
There are several legitimate reasons to take panels out of service. Which scenario you're in determines the right approach.
| Reason | Recommended Method | Duration |
|---|---|---|
| Roofing or construction work | Full opaque covers + rapid shutdown | Days to weeks |
| Storm preparation | Rapid shutdown only (tarps not recommended) | Hours |
| Extended vacation / system shutdown | Inverter AC disconnect | Weeks to months |
| Portable panel transport | Soft carry case | Transit only |
| Portable panel storage | Soft case, dry location | Weeks to months |
| Electrical work on home | Full system isolation by electrician | Hours to days |
The most common mistake? Covering panels with standard blue polyethylene tarps before roofing work. Blue tarps are partially translucent, so a covered panel on a bright day can still produce 10 - 20 volts at the terminals. If a roofer's metal tool touches an exposed terminal, that's an arc or shock. Only fully opaque black covers or rapid shutdown eliminate the hazard.
What Are the Safest Ways to Cover Solar Panels?
Option 1: Purpose-made solar panel covers
The safest and most practical solution. These are sewn from UV-resistant, opaque polypropylene or polyester fabric that blocks all light. They typically clip or strap around the panel frame. Prices range from $15 - $60 per panel depending on size. Brands like Covertech and custom covers from solar installers provide fire-retardant and weatherproof variants.
Option 2: Activate rapid shutdown (RSD)
Since NEC 2017, all new US residential solar installations require a rapid shutdown system (NEC 2023, Article 690.12). When triggered, RSD drops string voltage to under 30 V within 30 seconds - safe for emergency responders and rooftop workers. Many modern systems (SolarEdge, Enphase) have RSD built in. It's the safest approach for roofing work because it needs no physical covering at all. If your system predates 2017 or lacks RSD, opaque covers plus a DC isolator disconnect are your best alternative.
Option 3: Switch off the inverter's AC and DC isolators
For non-emergency shutdowns (extended absence, maintenance), switching off both the AC isolator (at the switchboard) and the DC isolator (at the inverter) stops the system from exporting power and disconnects the inverter. This does not eliminate panel-level voltage - panels still generate DC at the string level between the panels and the now-disconnected inverter. Physical covering is still needed if anyone is working near the panel terminals.
Option 4: Soft cases for portable panels
Portable 100 - 400 W folding panels (common in off-grid camping and van setups) should be stored in fabric carry cases when not in use. Close all Velcro or zipper closures to fully block ambient light. Disconnect any attached charge controllers or batteries before storing.
What Should You NOT Use to Cover Solar Panels?
Why do well-meaning DIY covers cause so many problems? Because most household materials either trap heat, scratch glass, or quietly let light through. Standard blue polyethylene tarps are the worst offender: partially translucent, heat-trapping, and not UV-stabilized for long outdoor use.
Never use:
- Clear or translucent plastic sheeting (still passes light, still generates voltage)
- Cardboard (gets wet, disintegrates, doesn't block enough light reliably)
- Plywood directly on panels (can crack glass under weight or thermal expansion)
- Standard poly tarps for anything longer than a few hours (heat buildup risk)
- Aluminum foil or metallic covers (conductive - creates short-circuit risk if it contacts terminals)
What About Covering Panels Before a Storm?
This is a common question, and the advice from solar panel manufacturers and NREL is consistent: don't cover panels before a hurricane or high-wind event. Here's why:
Any tarp or cover becomes a sail in high winds. The lift forces can crack glass, damage frames, and pull mounting hardware off the roof - damage that the uncovered panel would have survived. Certified solar panels (IEC 61215) are tested for hail up to 25 mm at 23 m/s, wind pressures of 2,400 Pa (equivalent to roughly 150 mph), and snow loads of 5,400 Pa. Your panels are almost certainly more storm-resistant than any improvised covering.
The better pre-storm checklist: confirm your inverter's rapid shutdown works, make sure mounting hardware is secure, photograph the system for insurance, and - if flooding is a risk - kill the main supply at the breaker panel. OSHA guidelines say treat all solar conductors as energized until a qualified person verifies otherwise.
For long-term health and to catch degradation from storm debris or aging sooner, panel-level monitoring via the SolarEdge P370 power optimizer gives per-panel output data that flags damage within days.
What Happens If You Leave Solar Panels Uncovered During Storage?
Decommission panels for a season and leaving them exposed piles up risk over time. Four things bite:
- Soiling: A few weeks of exposure lets dust, pollen, and bird droppings coat the glass. NREL data shows soiling losses can reach 5 - 25% of output. Panels stored flat (0 degrees tilt) foul fastest because rain can't wash them.
- Micro-cracks from thermal cycling: Disconnected panels in full sun still heat to 60 - 75 degrees C by day and cool overnight. Months of that stress propagates micro-cracks in the silicon wafers. Manufacturers recommend covering for storage past 30 days.
- Warranty: Tier-1 warranties (LONGi, Trina Solar, JA Solar) expect installation within 6 - 12 months of purchase. Panels stored outdoors uncovered can have claims challenged on improper-storage grounds. Keep receipts and dated photos.
- UV backsheet degradation: The rear backsheet resists reflected light from below, not direct overhead sun. Store panels vertically in racks or face-up with opaque covers.
For how these aging mechanisms compound, see our guide on old solar panels.
| Covering Method | Pros | Cons | Cost per Panel |
|---|---|---|---|
| Purpose-made panel covers | UV-resistant, fitted, breathable, fire-retardant options available | Must match panel dimensions; limited availability for uncommon sizes | $15 - $60 |
| Rigid polycarbonate sheets | Excellent impact protection, fully opaque, reusable | Heavy, requires mounting hardware, risk of scratching glass if improperly placed | $30 - $80 |
| Panel blankets (padded fabric) | Best for transport and storage, cushioned protection against impact | Not weatherproof for outdoor use, must be stored dry | $25 - $70 |
| Black polypropylene tarp | Inexpensive, fully opaque, widely available | Not breathable - traps moisture; degrades in UV after 6 - 12 months | $5 - $15 |
How Do You Maintain Covered Panels for Long-Term Protection?
When panels stay covered for weeks or months, inspect at least once a month - more in hot or humid climates. Moisture is the main enemy. Overnight temperature drops push humid air under the cover to dew point, and persistent moisture corrodes junction-box connections, degrades the glass-to-encapsulant bond, and grows mold on frames. Leave a 2 - 3 cm ventilation gap at the bottom edge to allow airflow while still blocking light.
When you bring a system back online, panel-level monitoring earns its keep. The SolarEdge P370 flags any panel that degraded during shutdown from the moment of restart. For tips on maximizing output afterward, see our guide on increasing solar PV yield. Curious whether panels produce anything after dark? Our guide on solar panels at night covers zero-light output.
Summary
Panels stay electrically live whenever any light reaches them. Fully opaque, purpose-made covers ($15 - $60 per panel) are the most reliable physical solution, while rapid shutdown eliminates panel-level voltage with no covering at all. For storms, leave panels uncovered - they're built to survive extreme weather, and improvised tarps add more risk than they prevent. For portable panels, use purpose-made soft cases. For cleaning schedules and inspection checklists, see our solar panel maintenance guide.