11.55 kW Ballasted Flat Roof Solar Project in Japan
This 11.55 kW rooftop project used 21 large-format 550 W modules arranged in three rows of seven. The mounting design paired 30° aluminum triangle frames with rails, module clamps, grounding parts and ballast plates, using a 34 m/s design wind speed and a 30 cm snow condition as project inputs.
Confirmed Project Parameters
The final project records define the module format, array arrangement, environmental inputs and main mounting components used for the order.
Large Modules and a 30° Tilt Required a Project-Specific Layout
The selected modules measured 2411 × 1134 × 35 mm. Their size and frame thickness affected rail position, clamp selection and the geometry of the supporting triangle assemblies.
The final drawing organized the modules into three seven-module rows. The mounting design was then coordinated around the confirmed array, rather than carrying forward quantities from an earlier layout revision.
- 2411 × 1134 × 35 mm framed modules
- Three rows with seven modules per row
- 30° fixed-tilt aluminum triangle assemblies
- 34 m/s wind-speed input and 30 cm snow condition
- Rails, clamps, grounding parts and ballast plates matched to the final BOM
How the Structural Components Worked Together
The final bill of materials combined the primary support frame with module rails, fastening components, electrical bonding parts and ballast interfaces as one coordinated assembly.
30° Triangle Assemblies
Al6005-T5 structural members formed the fixed-tilt support geometry for the rooftop array.
Y50 Rails & Splices
Module-support rails and rail connectors created practical continuous support across the three rows.
Clamps & Grounding Parts
35 mm module clamps, grounding clips and conductive components were matched to the confirmed module frame and rail interface.
Ballast Plates & Fasteners
Ballast plates and project fasteners completed the roof-support concept defined in the final mounting package.
From Layout Revision to Final BOM
The project records show a design process in which the mounting quantities were updated after the module and array configuration were confirmed.
Initial Concept
The first stage established the rooftop triangle-frame concept, rail direction and ballast interface.
Layout Revision
The module and array configuration were revised so the design reflected the actual project arrangement.
Final Drawing & BOM
The confirmed 21-module layout was translated into final quantities for frames, rails, clamps and related parts.
Order Preparation
The final configuration then moved into order confirmation and packing preparation.
Project Specification Table
These values describe this specific project and should not be treated as universal limits for other roofs or sites.
| Project type | Ballast-based flat-roof PV mounting project |
|---|---|
| Location | Japan |
| Project capacity | 11.55 kW |
| Module quantity | 21 modules |
| Module power | 550 W each |
| Module dimensions | 2411 × 1134 × 35 mm |
| Array arrangement | Three rows of seven modules |
| Tilt angle | 30° |
| Design wind speed | 34 m/s |
| Snow condition | 30 cm |
| Project design reference | JIS C 8955:2017 |
| Main structural material | Al6005-T5 aluminum alloy |
| Fastener / conductive materials | SUS304 stainless steel and project-specific conductive components |
| Primary mounting components | Triangle assemblies, Y50 rails, rail connectors, module clamps, grounding parts, ballast plates and fasteners |
| Documented project stage | Engineering design, final BOM, order confirmation and packing preparation |
Drawings, Components and Packing Reference
The following images illustrate the final array arrangement, support geometry, component set and shipment preparation for the project.
Final Array Layout
The approved drawing shows three rows with seven modules in each row and the corresponding support positions.
30° Triangle Detail
This view shows the fixed-tilt support geometry, module-support rail and ballast interface used in the design.
Component Set
The mounting package included structural frames, rails, connectors, clamps, grounding parts and ballast plates.
Packing Preparation
Structural members and smaller hardware were grouped for project shipment after the final order was confirmed.
What This Case Shows
Explore Flat-Roof System Information
Use the related pages below for broader system selection information; this case study remains a record of one specific project configuration.
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Share the roof layout, module dimensions, required tilt, site wind and snow conditions, allowable roof load and preferred roof interface. The mounting configuration can then be reviewed against the actual project inputs.
- Roof type and usable area
- Module size, frame thickness and quantity
- Required tilt and array orientation
- Wind and snow design inputs
- Allowable roof load and structural information
- Roof-interface or attachment requirements