When planning a solar energy project, accurately estimating the number of racking system components—such as rails, clamps, support legs, and connectors—is essential. Whether it’s on a roof or the ground, a good mounting structure helps the project work better. It lowers costs and keeps performance steady in wind and snow.
This guide shows you how to estimate the amount of different mounting parts. It considers system capacity, layout, and installation type. We’ve also included a standard estimation table to help you quickly create an initial bill of materials (BOM).
Why Is Solar Racking Quantity Estimation Important?
The mounting system is not just a supporting structure—it is the backbone of your entire PV system. Underestimating components can delay installation, while overestimating leads to unnecessary expenses. A proper estimate in the early design stage helps control costs and improves installation efficiency.
Step-by-Step Guide to Estimating Mounting Component Quantities
1. Calculate the Number of Solar Panels
Start by calculating how many solar panels your system needs.
Formula:
Number of Panels=Total System Capacity(W)/Panel Power Output(W)
Example:
- System Size:100kW
- Panel Power:550W
- Result:100,000/550≈182 panels
2. Choose a Panel Arrangement (e.g., 1P, 2P, Landscape, Portrait)
Your layout impacts how many mounting groups are needed. Common configurations include:
| Layout Type | Panels per Group | Estimated Number of Groups |
|---|---|---|
| 1P (Single Portrait) | 1 | Equal to the number of panels |
| 2P (Double Portrait) | 2 | Panels/2 |
| 3P Landscape | 3 | Panels/3 |
Example (2P Vertical):
Mounting Groups=182/2=91 groups
3. Estimate Rail Requirements (Typically Aluminum Rails)
Each group usually requires two rails. Calculate total length based on panel dimensions and extra for connections.
Example:
- Rail per Group:2*2.3m=4.6m
- Total Length:91*4.6m=418.6m
- If using 6m rails:418.6/6≈70 rails
Recommendation: Order 72 rails for buffer stock.
4. Calculate the Number of Clamps (Mid Clamps & End Clamps)
| Clamp Type | Usage | Estimation Formula | Total Needed |
|---|---|---|---|
| Mid Clamps | Between adjacent panels | 2 per group | 91*2=182 |
| End Clamps | At the ends of each group | 4 per group | 91*4=364 |
5. Estimate Support Legs or Bases
Each group typically requires 4 base parts (L-feet,ground feet,or steel connectors).
Support Legs=91*4=364 units
6. Other Recommended Accessories
| Accessory | Description | Suggested Quantity |
|---|---|---|
| Rail Splice Kits | Connect two rails together | Approx. 36 pieces |
| Grounding Clips | One per mounting group | 91 clips |
| Grounding Wire | For bonding between rails and racks | Around 80–100 meters |
| Wind Bracing Kit | Recommended for high-wind areas | Custom per project design |
100kW Solar System (2P Layout) – Mounting Component Estimate Table
| Component | Quantity |
|---|---|
| Solar Panels | 182 panels |
| Mounting Groups | 91 groups |
| Rails (6m per piece) | 72 rails |
| Mid Clamps | 182 pieces |
| End Clamps | 364 pieces |
| Support Legs / Bases | 364 pieces |
| Rail Splice Kits | 36 pieces |
| Grounding Clips | 91 pieces |
| Grounding Wire | 80–100 meters |
Get a Free Mounting BOM Estimate for Your Solar Project!
We provide free material estimation services for customers worldwide. Whether you’re working with ground mounts, metal rooftops, or concrete roofs, we can help.
Just share the following details:
- System Size(kW or MW)
- Solar Panel Model/Dimensions
- Installation Type(Rooftop/Ground)
- Layout Method(1P,2P,Landscape,or Portrait)
- Site Wind and Snow Load(if applicable)
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