11.55 kW Ballasted Flat Roof Solar Mounting Project in Japan
A project-specific ballast-based flat-roof mounting configuration developed for 21 large-format PV modules in Japan. The system combined 30° aluminum triangle frames, rails, module clamps, grounding parts and ballast plates under a 34 m/s design wind input and 30 cm snow condition.
Key Project Parameters
The final configuration used three 7-module rows with a 30° tilt and a project-specific ballast-based support structure.
Supporting Large-Format Modules at a 30° Tilt
The project used large-format 2411 × 1134 × 35 mm PV modules, so the mounting configuration needed to coordinate module length, rail position, triangle-frame geometry and ballast support rather than relying on a small standard rooftop bracket.
The final engineering drawing grouped the 21 modules into three 7-module rows and used a 30° tilt. This required a consistent support rhythm across each row while keeping the component set practical for fabrication, packing and installation.
- Large-format 2411 × 1134 × 35 mm modules
- Three 7-module rows for a total of 21 modules
- 30° fixed tilt using aluminum triangle support frames
- 34 m/s design wind input and 30 cm snow condition
- Ballast plates integrated into the roof-mounting configuration
- Matched rails, clamps, grounding parts and stainless-steel fasteners
Ballast-Based Triangle Mounting with a Complete Hardware Set
The project BOM shows a coordinated mounting assembly rather than a standalone triangle bracket.
Aluminum Triangle Frames
The support assembly used Al6005-T5 longitudinal members, square tubes, bottom beams, spacers and sleeves to form the 30° rooftop triangle structure.
Y50 Mounting Rails
Aluminum mounting rails supported the large-format modules and connected the module rows to the underlying triangle-frame structure.
Rail Connectors
Rail splice components were included so the module-support rails could be divided into practical lengths for fabrication, shipment and field assembly.
Mid & End Clamps
35 mm module-frame clamps were matched to the panel frame thickness and rail interface for the final 21-module configuration.
Grounding Components
Grounding clips and conductive parts were included in the BOM to coordinate module-to-rail electrical continuity within the mounting assembly.
Ballast Plates
Dedicated ballast plates formed part of the rooftop support concept and were matched to the triangle assemblies and overall structural layout.
From Initial Configuration to Final Order
The project documentation shows a normal engineering revision process before the final order configuration was confirmed.
Initial Mounting Concept
The first design stage established the triangle-frame concept, module support direction and ballast-based roof interface.
Module & Layout Revision
The module and array configuration were revised before the final design, reflecting the actual project requirements.
Final Drawing & BOM
The final 21-module, 550 W configuration was translated into mounting quantities for frames, rails, clamps and ballast parts.
Order & Packing Preparation
Contract and packing records show that the project moved beyond design into order execution and shipment preparation.
Engineering Reference Summary
Public project information is limited to useful engineering parameters. Customer identity, pricing, bank information, internal part numbers and confidential commercial data are excluded.
| Project Type | Ballast-Based Flat Roof Solar Mounting Project |
|---|---|
| Location | Japan |
| Project Capacity | 11.55 kW |
| Module Quantity | 21 modules |
| Module Power | 550 W |
| Module Size | 2411 × 1134 × 35 mm |
| Array Arrangement | 7 × 1 × 3 rows |
| Tilt Angle | 30° |
| Design Wind Speed | 34 m/s |
| Snow Condition | 30 cm |
| Design Reference | JIS C 8955:2017 project basis |
| Main Structural Material | Al6005-T5 aluminum alloy |
| Fastener / Conductive Materials | SUS304 stainless steel and project-specific conductive components |
| Support Concept | 30° aluminum triangle-frame structure with ballast plates |
| Primary Components | Triangle assemblies, Y50 rails, rail connectors, module clamps, grounding parts, ballast plates and fasteners |
| Project Stage Supported by Records | Engineering design, final BOM, order confirmation and packing preparation |
Representative Project Views
Use simplified or anonymized versions of the project documents so customers can understand the mounting concept without exposing customer names, addresses, prices or internal production information.
Three 7-Module Rows
Show the final 7 × 1 × 3 module arrangement and support positions from the approved configuration.
Triangle Frame & Ballast Interface
Show the 30° triangle geometry, module-support rail and ballast position without publishing internal dimensions unnecessarily.
Matched Mounting Components
Use a clean component overview for triangle frames, rails, clamps, grounding parts and ballast plates.
Project Packing Preparation
Use anonymized packing or material-group images to show how structural members and small hardware were organized for shipment.
The public case should describe this as a ballast-based roof mounting configuration. Do not claim a fully non-penetrating installation unless the final roof attachment method is independently confirmed.
Flat Roof Mounting Is More Than Choosing a Triangle Angle
This project shows how a rooftop triangle mounting system must be coordinated with the actual module dimensions, rail lengths, clamp interfaces, ballast support and project wind and snow conditions.
It also demonstrates the value of revising the mounting design before production when the module or final array configuration changes. The final BOM should reflect the actual project rather than an earlier layout.
- Large modules change rail, support and clamp geometry
- Higher tilt angles affect the overall mounting configuration
- Ballast components must be considered together with the support frame
- Wind and snow inputs belong in the mounting-system review
- Final BOM quantities should follow the confirmed module and array layout
- Design revision before production helps avoid mismatched project hardware
Flat Roof Mounting Products Used for Similar Projects
Planning a Flat Roof Solar Mounting Project?
Send Easy Solar your roof layout, PV module dimensions, required tilt, wind and snow conditions, allowable roof load, preferred attachment method and project quantity. Our team can review the mounting configuration and prepare a project-based solution.
- Roof type and usable roof area
- PV module size, frame thickness and quantity
- Required tilt and array orientation
- Wind speed and snow conditions
- Allowable roof load and structural information
- Ballast or attachment preference
- Available roof drawings, photos or layout files