Kundenspezifische halbstarre Solarmodule: OEM- und ODM-Lösungen für Marine-, Wohnmobil- und netzunabhängige Produkte

Standard panels are built for roofs. Your application probably is not a roof.

That gap is why semi-rigid solar modules exist, and why so many brands end up commissioning a custom build instead of buying from a catalog. What follows covers the problems buyers actually hit, the engineering that solves them, and how an OEM or ODM program runs from first email to production.

Weight and thickness fight the application

A framed glass module is heavy. Our rigid CLM-150MBC weighs 7.5 kg and stands 30 mm tall. On a ground mount, that is entirely fine. On a caravan roof, a boat deck, or a portable power kit, it is a genuine problem.

Every kilogram bills you somewhere. On a vehicle it eats payload. On a boat it raises the centre of gravity. On a shipped consumer product it lands on the freight invoice for every unit you ever sell.

The mounting surface is rarely flat

Boat decks curve. Van roofs curve. Trailer lids, drone bodies, and telecom cabinets all have shape to them, and rigid glass follows none of it. So installers bridge the gap with rails, brackets, and spacers — hardware that adds height, drag, cost, and one new leak path per fastener.

Nobody can walk on it

Deck and roof space is finite. A solar panel that cannot be stepped on becomes an obstacle. The owner then loses that space twice over: once to the panel, once to the walkway left around it.

The voltage does not match the system

Most catalog PV panels are built for grid strings, while off-grid products usually run at 12 V or 24 V. Choose wrong and the controller either discards output it could have used, or never quite reaches the charging threshold on a dull morning.

The solar panel does not fit — and it is not yours

Real products have real dimensions. A hatch is 980 mm wide, a cabinet lid is 620 mm, and the catalog panel is 1,134 mm; you cannot trim a laminated solar module down afterwards. Then there is the label. Ship a solar panel carrying another company’s name and you are not building a brand, you are reselling one.

Insight 1: “Semi-rigid” describes a structure, not a material

This one trips up a lot of buyers, because flexible and semi-rigid solar panels often share the same front film and the same encapsulant. The difference sits underneath, out of sight.

A flexible panel has no structural plate; it bends freely and leans on whatever surface it is mounted to. A semi-rigid solar panel has a backing plate bonded into the laminate, and that plate is what carries load and sets stiffness.

So when a supplier says “semi-rigid,” one question settles most of it: what is the backing plate made of, and how thick is it?

Insight 2: The backing plate sets almost everything

No single option wins outright. A walkable solar deck panel and a lightweight drone panel pull in opposite directions. That makes the plate the first real engineering decision in any project, and the one most worth arguing about early.

Insight 3: ETFE is doing more than replacing glass

ETFE is a fluoropolymer film, and the numbers worth trusting come from the resin makers rather than from panel brochures. AGC produces its Fluon ETFE film across a 12 µm to 250 µm range and reports that a 50 µm film transmits roughly 95% of incident light. Solar frontsheets generally sit in the tens-of-microns to low-hundreds band, and the choice is a straight trade: thicker film resists abrasion better, thinner film passes more light.

Durability is the stronger part of the case. AGC reports almost no degradation after 16,000 hours of accelerated weathering, which it equates to more than thirty years outdoors. It also cites a water contact angle of 106°. That last figure is why dirt and salt film rinse away instead of bonding.

Textured ETFE brings one more benefit worth naming: a non-skid surface. That texture is what makes a walk-on panel usable on a wet deck rather than a hazard.

Insight 4: Back-contact cells suit semi-rigid builds unusually well

Back-contact (BC) cells move every electrical contact to the rear, leaving the front face completely clear. In a compact, glass-free module that buys you four things.

Shade behavior. A TÜV NORD study reported in PV Magazin found that a single fully shaded BC cell costs about 12.9% of module power, against roughly 33.9% for a comparable TOPCon module. The mechanism is specific. A BC cell breaks down at around 5 V, but roughly 15 V of total reverse bias is needed before the bypass diode activates. Current keeps flowing, in other words, where a TOPCon substring would already have switched itself out.

Two limits belong next to that number, and they are rarely quoted. First, the advantage was measured with shading spread across different substrings within one string. Second, it fades fast — BC leads while three or fewer cells are shaded, and once shading passes four cells both technologies converge on losses near 50%. A separate Trina Solar and Nanchang University study, published in August 2025, found the same threshold. BC therefore wins on light, patchy shade: a rail, a mast, a leaf, a bird dropping. Park it under a real shadow and the advantage is gone.

The counter-evidence deserves airtime too. In TÜV Nord–verified field testing at Kagoshima, Japan, a TOPCon module recorded a 94.19% performance ratio against 91.99% for p-type BC and 89.29% for n-type BC. Those tests were commissioned by TOPCon manufacturers, so read them with that in mind — but the underlying point is sound. Shade tolerance is one variable among several, not the whole yield story. For compact off-grid products with obstructions permanently close by, it is usually the variable that decides the outcome. On a clear, unshaded array, the case for BC rests on other things entirely.

Heat behavior. BC modules typically carry a P_max coefficient near −0.26%/°C. Be precise about the size of that gain, though: LONGi puts the improvement over TOPCon at about 0.03%/°C, which places mainstream TOPCon near −0.29%/°C. A real edge, then, but a modest one. It counts most where cells run hot. A panel bonded flat to a deck, with no airflow behind it, runs very hot indeed. That is also the flip side: the same mounting style eats back part of what the cell technology just gave you.

Mechanical stress. A busbar-free front face has fewer stress concentrations, and that matters in a panel expected to flex slightly and get stepped on.

Appearance. No gridlines, no visible interconnect. On a yacht deck or an architectural surface, uniform black simply looks finished.

Insight 5: The cover does not set the power — the cells do

Here is a comparison that surprises people. Take our rigid CLM-150MBC and rebuild the identical 3 × 12 back-contact array as a semi-rigid ETFE laminate. Same cells, same series count, same footprint. The electrical specification comes out the same, because glass was never generating the power in the first place.

Optically that holds up. AR-coated solar glass and a thin ETFE frontsheet transmit within a couple of points of each other, so a like-for-like cell array delivers like-for-like watts. What changes is everything structural — which is the whole proposition.

Read down the table and the argument makes itself. Every electrical row matches. What is left is 25 mm of thickness and several kilograms. On a boat or a van, that was always the only difference that mattered.

Why the diode count is a range, not a number

Notice that the semi-rigid example lists one to three bypass diodes rather than a fixed figure. That is deliberate, because on a small module the diode count is a design decision with real consequences.

A single diode is cheapest and needs the least room in a low-profile junction box. It also protects the solar module as one block, so when shade triggers it, the whole solar panel drops out. Two diodes split a 36-cell string into halves. Three cut it into thirds: a shaded corner then costs a third of the output rather than all of it, at the price of a larger box and more interconnect.

There is a BC-specific wrinkle worth knowing here. Because BC cells break down softly, they tolerate mild shade internally before the diode is called on at all, which changes where the diode boundaries usefully fall. On a walk-on panel the physical constraint often decides it anyway: a thin laminate leaves limited room for the junction box, and low-profile boxes hold fewer diodes. So tell us the shading pattern you expect, and the count follows from that rather than from a catalog default.

Voltage is a design choice, not a fixed property

Series cell count sets voltage; cell size and layout set current. Change either and the solar panel’s system fit changes with it. Voltage is the most under-used lever in custom module work, and the one that most often gets settled too late.

So the CLM-150ME string wants MPPT, which turns that surplus voltage into extra charging current. Treat that as a feature, not a constraint. Higher array voltage also means thinner cable and less voltage drop over a long run — exactly what a boat or bus roof needs.

If the product has to work with a low-cost PWM controller, say so in the brief. We then build a genuine 12 V nominal string with V_mp in the 17–18 V band — same solar panel format, different series count. Which is precisely why voltage belongs in the first email rather than the last.

CLM-150ME is shown here as an illustrative configuration built on the CLM-150MBC cell array. Final values are confirmed on the approved drawing at time of order.

Insight 6: OEM and ODM are not the same purchase

In practice most projects land between the two columns. A buyer turns up with a rough sketch and a battery voltage, and the factory fills in the layout. That works perfectly well, provided everyone is clear about who signs off on what.

Insight 7: Test data beats a certificate wall

Custom variants are usually built to meet or exceed IEC standards rather than certified individually, since each variant is a design in its own right. It is worth being precise about what that sentence means. “Built to IEC 61215 construction” is a manufacturing claim; a certificate is a third-party test report tied to one specific bill of materials. They are not interchangeable.

Which one you need is decided by the destination market, not by the panel. A module bonded to a boat deck or a vehicle roof counts as mobile equipment and falls outside building codes. Fix a module to a building in the US and it generally needs NRTL listing to UL 61730 before an inspector will pass it. UL Solutions sets out how the NEC, IBC and IRC drive that requirement. In the EU, CE marking obligations apply. Settle this at the brief stage, because retro-fitting certification onto a frozen design is the most expensive mistake in this category.

For the technical reference points, IEC 61215-2:2021 is the document to know. Its second edition added a bending test (MQT 22) built specifically for flexible modules. Cyclic mechanical load (MQT 20) and PID detection (MQT 21) arrived in the same revision. Static load (MQT 16), damp heat, thermal cycling and humidity-freeze cover the moisture and fatigue side. That edition also revised the bypass diode thermal test (MQT 18), which matters if your build carries more than one diode.

What you can customize

• Dimensions, shape, and corner radius
• Power, V_mp, V_oc, and cell layout for 12 V, 24 V, or higher
• Backing plate material and thickness
• Bypass diode count and substring boundaries
• Front surface: clear, textured, or non-skid
• Backsheet color, including full black
• Cable length, gauge, exit position, and connector type
• Junction box style, including low-profile and side-exit
• Mounting method: eyelets, adhesive-ready surface, bonded studs, or edge banding
• Cell technology: HPBC standard, with ABC or TBC available
• Private label, printed logo, serial numbering, and custom packaging

1. TÜV NORD study finds back-contact advantage over TOPCon is limited to mild shading conditions — pv magazine, 8 July 2026. Source of the 12.9% / 33.9% single-cell figures, the four-cell threshold, and the 5 V breakdown / 15 V diode-activation mechanism. Reports the paper “A comparative study on the performance of BC and TOPCon modules under partial shading conditions,” published in Sonnenenergie, and the August 2025 Trina Solar / Nanchang University study reaching a comparable threshold.
2. JinkoSolar, Trina say TOPCon modules outperform p-type back-contact panels — pv magazine, 18 October 2024. Independent reporting on the TÜV Nord–verified Kagoshima field tests and the 94.19% / 91.99% / 89.29% performance ratios.
3. LONGi Hi-MO X10 / HPBC 2.0 launch — LONGi. Source of the −0.26%/°C coefficient and the ~0.03%/°C delta versus TOPCon.
4. IEC 61215-2:2021 — Terrestrial PV modules: design qualification and type approval, Part 2: Test procedures (IEC Webstore). Second edition adds MQT 20, MQT 21 and the MQT 22 bending test for flexible modules, and revises the MQT 18 bypass diode thermal test.
5. IEC 63092-1:2020 — Photovoltaics in buildings, Part 1: Requirements for BIPV modules.
6. BIPV system testing and certification — UL Solutions, on NRTL listing and UL 61730 under the NEC, IBC and IRC.
7. Fluon ETFE Film Und Functions and advantages — AGC Chemicals. Film thickness range, 95% transmittance at 50 µm, 16,000-hour weathering result, 106° contact angle.
8. Which solar charge controller: PWM or MPPT? — Victron Energy technical note. Explains why a PWM controller pulls array voltage down to battery voltage.
9. Semi-Rigid Solar Panels for Boats, Vans and Dock Decks — Couleenergy.
10. HPBC oder ABC? Vergleichen Sie die Back-Contact-Solarmodultechnologien — Couleenergy.
11. BC Solar Modules, Flexible Panels and OEM Custom Solutions from China — Couleenergy.
12. Solarmodule im Schatten: HPBC 2.0, ABC vs. TOPCon im Vergleich — Couleenergy.