Solar panels, hail and impact damage: what the rating really means

Solar panels are designed for outdoor service, and a suitable, correctly installed panel can withstand a range of weather conditions. Hail resistance still has limits. It is worth understanding those limits before buying, and knowing what to do if a storm or another impact damages your array.

Our starting point is straightforward: choose quality equipment with evidence behind its claims, then make sure there is someone you can contact when its condition needs checking.

What does a hail rating actually mean?

A common baseline in IEC 61215 hail qualification uses laboratory-made ice balls 25 mm in diameter at 23 metres per second, approximately 83 km/h. That describes a controlled test, not a promise that the panel will survive every storm. Kiwa PVEL explains the baseline in its hail-test guidance.

Ask for the evidence covering the exact module model and construction offered. What ice-ball diameter and speed were used? What condition was checked afterwards? A larger wattage number, a familiar brand or the words “hail resistant” do not answer those questions.

A steel-ball demonstration is not interchangeable with an ice-ball test. The material, mass, speed and impact conditions matter. A video can show what happened to that sample; it does not establish a different test qualification.

Stronger testing exists, but check the details

The IEC publishes IEC TS 63397, guidance for increased hail resistance, specifically addressing exposure beyond the IEC 61215 series. Independent laboratories also offer more demanding assessments. Kiwa PVEL's current hail programme examines glass breakage and cell damage using larger laboratory-made hail. That does not mean every panel carries those results.

Compare the actual report and the product it covers. The panel's glass, cells, frame and other materials form one assembly. A result for another construction is not automatically a result for yours.

The installed system matters too. The mounting structure and clamp arrangement must follow the relevant instructions. Canadian Solar's installation manual, for example, specifies authorised clamping positions and assigns the support-structure design and load calculations to the designer and installer. Correct mounting supports reliability; it does not make the glass indestructible.

Intact-looking glass does not rule out damage

A storm can damage cells inside a module without leaving an obvious shattered front sheet. The US Department of Energy warns that hail-related microcracks can grow over time, reducing production and increasing hot-spot and fire risk. Some damage requires specialist imaging to identify.

Equally, a crack is not proof that a fire will follow. The practical point is that appearance and today's energy reading cannot establish the condition of the whole module. Continued production is useful information for the technician, but it is not a safety clearance.

Golf balls, bullets and other impacts need attention too

Hail qualification is not a golf-ball rating or ballistic protection. A golf-ball strike, bullet strike or other hard-object impact can crack or puncture a panel and compromise its protective layers. The location and severity of the strike determine the damage; it should not be dismissed because only a small area looks affected.

Golf-ball and bullet damage can create a fire hazard by opening a path for water. Where the protective layers are breached, moisture can reach parts intended to remain protected. Moisture can contribute to corrosion, leakage currents and insulation faults. Damaged electrical paths or connections may also overheat or arc, creating a possible fire hazard. This is a risk pathway, not a claim that every strike admits water or starts a fire.

The distinction matters: published research on moisture and module insulation describes corrosion, ground-fault and safety concerns; JinkoSolar's installation manual explicitly identifies broken glass as a possible electric-shock or fire hazard. These sources support treating compromised modules seriously. They do not certify any panel against golf balls or bullets.

What should an owner do after an impact?

Keep people away from visibly damaged equipment and contact a qualified solar technician promptly. Do not climb onto the array, touch broken glass, unplug connectors or try to seal a hole. Panels can generate electricity in daylight even when the inverter is off. Canadian Solar also warns that the shock risk from cracked or broken modules increases when they are wet.

From a safe position, record when the incident happened, take photographs if accessible, and save any monitoring alarms. Give the technician the module details and purchase records you already have. Ask for the array and associated wiring to be assessed, rather than assuming the most visible broken panel is the only affected component.

Let the qualified person decide how to make the system safe, what inspection or specialist testing is appropriate, and which modules need replacement. Jinko's guidance calls for broken-glass modules to be replaced; a cosmetic patch does not establish restored insulation or certification.

Buy with the next conversation in mind

Before ordering, ask about the exact module's test evidence, installation requirements and damage-support route. Keep warranty terms and insurance cover separate from the question of whether a damaged panel is safe.

Our Ballito team can help with product information and the right support conversation, including manufacturer clarification where needed. Quality products, practical local advice and a clear route for technical questions are useful long after the order has arrived.