Select a solar module by passing three separate checks: it fits the supported mounting area, its electrical characteristics match the receiving system and the proposed installation can be evaluated against the load. Rated watts alone answer none of those questions. Keep a raw module and a folding charger with regulated ports in different comparisons.
1085 × 510 × 2 mm (±2 mm)
1300 × 1020 × 2 mm (±2 mm)
1662 × 790 × 2 mm (±2 mm)
Rectangles compare the stated dimensions at one scale. A similar footprint does not establish electrical or mounting compatibility.
Start with three gates, in order
| Gate | Information to obtain | A reason to pause the shortlist |
|---|---|---|
| Mechanical fit | Usable length and width, support, cable exit, connector clearance, permitted mass | Only the overall roof size is known; supports or obstructions are not |
| Electrical match | Module voltage/current characteristics and controller input limits; battery and output architecture | A connector fits, but accepted voltages or charging behaviour are unknown |
| Energy task | Load profile, operating time, location, shading and required operation without solar input | Headline module watts are being treated as continuous load power |
A thin profile is not a bend-radius specification. Request the selected module’s handling and mounting instructions rather than treating “lightweight” as a structural approval.
Compare the type of product before its power
The 100 W, 240 W and 308 W entries describe lightweight modules with different mechanical and electrical envelopes. They belong in a module-to-controller review.
The 60 W folding charger has a separate listed USB-C PD output limit. If the device will use that port, compare the port capability and receiving device as well as the array. See solar wattage versus port output.
A mechanical-envelope example
The published 240 W entry lists 1300 × 1020 × 2 mm (±2 mm). Using the nominal length and width:
Nominal rectangle = 1.300 m × 1.020 m = 1.326 m²That rectangle is a screening input. It does not include the clearance, support, cable route or service access required by a final installation. It is also not an instruction to infer bend tolerance, output or efficiency from area alone.
Keep voltage matching and energy estimates separate
Record the controller or inverter’s complete input window, not just a nominal battery voltage. Ask for the module characteristics and temperature conditions needed by the responsible engineer to check that window.
For energy estimates, the JRC PVGIS manual shows why location, exposure and modelling inputs matter. A model for a defined site does not establish performance on a moving vehicle or a frequently shaded portable product. This guide does not assign a generic daily yield to a catalogue module.
What should leave the selection review?
Keep one record with the candidate model, available mounting envelope, receiving electrical system, document revision and unresolved questions. Define what the sample must establish before ordering it: fit, charging behaviour or another specified interface task.
Continue with custom solar for OEM devices or the mobile roof application. Request current documents for the actual configuration before procurement.
Sources & method
The examples use the published product entries. Envelope arithmetic is a planning illustration, not a mounting drawing, module-efficiency calculation or measured energy-yield result.