Solar Mounting Structure Design for BTS Site

ABSTRACT There are a lot of key factors that should be taken into consideration before designing the Solar PV Mounting Structure. This version of Nizam Energy Energy’’s Technical Application Papers explain the design criteria of our Mounting Structures. Asad Idrees Assistant Project Coordinator Nizam Energy

SOLAR PV MOUNTING STRUCTURES Technical Application Papers - Vol. 6

Table of Contents Mounting Types Influence Factors of Mounting System Design Design Features of Nizam Energy’s Mounting Structure Mounting Structure for BTS Sites

Classification of PV Mounting Structures Fixed

Installation Site

Foundation

Materials

Fixed Mounting Solution

Ground Mounting

Concrete

Steel

Adjustable Solution

Roof-top Mounting

Spiral Piles

Aluminum Alloy

Tracking Solution

BIPV

C Type Steel

Fiberglass Reinforced Plastic

……

Carport

Ballast

Plastic

……

……

Composite Material

Influence Factors on PV Mounting Design A. Environment (Wind, Snow, Soil/Rock Conditions, Frozen Soil All environmental factors have to be considered in the design process for mounting structures (above ground) and foundations. All environmental factors have a significant impact on construction time and costs! Structures (above ground) Higher wind speeds 

Wind

bigger profiles (20% more wind speed leads to 50% more load!!)

Snow

Higher snow loads  bigger profiles

Foundations (below ground)

Strategies

Higher loads on foundations

Strengthen the material and adopt

 more or bigger

the front wall structure to reduce the

foundations

total cost.

Higher loads on foundations

Strengthen the material , decrease

 more or bigger

the post height and reduce the

B. Influence of System Design (Module Layout, Type, Tilt Angle) The layout, type and tilt angle of module are the key factors to affect the design of mounting structure and foundation.

Description

Structures (above ground)

Foundations (below ground)

No more than 4 modules in

Layout

vertical , the span is less than

select and optimize the Bigger Span bigger

Bigger Span bigger

profile properly according to

profile cross section

foundations

the different layout of modules

7m Frameless Module

Type

Module with Frame

Special Module

Tilt Angle

Special Clamps change the cross section of Common Clamps

Different Module 

profile, increase the

different foundation

parameters of cross section

settlement

and reduce the deflection on modules

Depending on the situation bigger angle  bigger

0-60°

Strategies

windward side and cross section

Bigger angle bigger

considering the frond wind

foundations

effect and design separately

C. Atmosphere Corrosion Conditions According to the environment classification, the loss rate of hot-galvanization layer in different atmosphere conditions is as follows; (In accordance with the ISO14713 environment classification, the corrosion risk and loss rate of hot-galvanization layer)

Code

C1

Corrosivity category

Interior: dry

Corrosion risk

Corrosion rate（Average thickness loss for zinc,

mm/year）

Very low

≤0.1

Low

0.1-0.7

Medium

0.7-2

High

2-4

Interior: occasional condensation C2 Exterior: exposed rural inland Interior: high humidity, some air pollution C3 Exterior: urban inland or mild coastal Interior: swimming pools, chemical plants etc C4 Exterior: industrial inland or urban coastal

C5

Exterior: industrial with high humidity or high salinity coastal

Very high

4-8

Im2

Sea water in temperate regions

Very high

10-20

Design Features of our Mounting Structures A. The Load Partition Design Through aerodynamic software analysis, determine the load partition and the overall influence on solar farm caused by wind flow, which can help save the cost of solar farm.

B. Easy Installation Through structure check installation test, we reduce the number of fittings required on site by delivering a preassembled mounting structure in the form of different packages. These Packages are classified to facilitate the material distribution on site.