Strapping solar module pallets: from the packing line to site unpacking

Solar module volumes grew sharply going into 2023. SolarPower Europe’s Global Market Outlook, reported by pv magazine in June 2023, put global installations in 2022 at 239 GW, about 45% more than the year before, and forecast 341 to 402 GW for 2023. Each gigawatt is a very large number of modules moved on pallets from factory to warehouse to site.

Module pallets are an unusual strapping application. The load is tall, glass-faced, light for its volume and easily damaged by point loads. The people unpacking it are often working outdoors on a project site, with a knife. That combination makes the strap specification and the unpacking instruction equally important.

How module pallets are strapped

Manufacturers describe their packing in installation and handling manuals. A useful example is the LONGi Hi-MO 6 product manual, English version dated March 2022. Its packaging diagram shows:

• modules standing vertically and strapped together internally;
• module corner protectors, and external corner protectors on the pallet;
• a cardboard sleeve over the stack, with plywood dividers on double-glass models;
• external strapping around the pallet and sleeve;
• straps interconnecting stacked pallets;
• an outer plastic film for basic dust and water protection.

The manual notes that pallet printing, labelling and the packing method may vary by product type and batch, so the diagram is an example rather than a universal pattern.

That is three separate strapping jobs. Internal straps hold the modules as a block inside the sleeve. External straps hold sleeve, pallet and corner protection together for handling and transport. Interconnecting straps link stacked pallets. A failure in one is not fixed by tightening another, and each needs its own place in the packing instruction.

Transport and storage limits that affect the strap

The same manual sets limits worth carrying into any packing or logistics instruction:

• Pallets are not completely moisture-proof, and their structural integrity falls when they get wet. Keep them dry and ventilated.
• Stacking is limited. The manual sets a stacking limit for transport and storage, and at unloading it says not to exceed the maximum number of pallets printed on the box, given as two.
• For intermediate transfers in non-factory vehicles or containers, pallets should be secured, with padding such as inflatable bags where the gap to the wall exceeds 10 cm.
• Pallets should not be unpacked for long-distance transport or long site storage.

For anyone re-strapping module pallets, for example a distributor splitting full pallets into smaller deliveries, these points become strap decisions. Corner protection must be replaced, not left out. External straps must not crush the sleeve’s top edges. And the joint should sit on a flat face where it cannot press into glass or a frame.

Unpacking: the moment the strap comes off

LONGi’s unpacking steps are specific:

• place the pallet on flat ground before opening;
• use scissors or a utility knife to cut the outer packing straps, taking care not to cut into the backsheet or frame;
• never unpack the upper pallet while pallets are stacked;
• work with at least four people, two of them holding the short sides so modules cannot tip while the sleeve is lifted;
• lean the modules against a solid support before taking them out;
• for a transport damage claim, photograph the whole pallet before cutting individual modules loose.

The point about photographs matters to buyers as much as to installers. Once the internal straps are cut, the evidence of how the load arrived has gone.

A re-strapping checklist for distributors and packers

Check	Reason
Use the module manufacturer’s packing instruction as the reference	Warranty and claims may depend on it
Replace corner protectors under every external strap	Glass and frames are sensitive to point loads
Set tool tension for module pallets separately from heavy loads	Over-tension crushes sleeves and corners
Keep joints on flat faces, away from glass and frames	Clips and welds can mark or press into the load
Label split pallets with module type, quantity and current class	Modules of the same current class are installed together
Photograph pallets at dispatch	Supports any claim on arrival

The current-class point comes from the same manual: modules of the same current rating should be installed in the same string, so a label on a split pallet should preserve that information. Our distributor identification guide covers the wider labelling discipline.

Strap and closure choices

Whatever strap a packer uses for module pallets, specify the width, thickness, joint method and tool together, and trial a pallet through realistic handling before standardising. If clips are used, check that they cannot bear on the frame or glass. Our guide to strapping over sharp edges covers the contact-path questions for frames and corners, and the receiving checklist helps confirm deliveries of strap and clips match the approved items.

Re-palletising modules and accessories

YAKU supplies PET strap on request and sheet metal clips for joining PET and PP strap. If you re-palletise modules or pack mounting accessories, send the pallet dimensions, tool and strap details through our enquiry page. Joint performance for a specific combination is on request.