Factory inspection

To control where and how a module is built?

The « Factory Inspection » is the assessment of the manufacturing steps designed to transform a set of independent materials into a photovoltaic module. The inspection of the different materials, manufacturing steps and parameters is essential in order to make sure that the performance but also the safety of the modules and thus the PV installation are constant

The factory inspection aims at controling the manufacturing quality of the PV modules and the respect of use of materials specified in the certificate. This check is required in order to guarantee that the manufacturing factory owns and uses all the resources necessary to obtain a final output (module) with a certain quality level.

Unfortunately, numerous design offices) or other organizations undervalue this control, because it exists neither standards upon which to base nor persons with enough expertise.

Otherwise, it is important to distinguish the factory inspection the bankability. On one hand, a complete audit of the company (financial, administrative, and technical) is usually carried out for the bankability control. On the other hand, the technical factory inspection is undertaken with an objective of profitability and financial safety. So, quality and sustainability are not checked in this last case.

The oversight bodies and accredited labs, like ELIOSYS, base their work on recommendations written by the IECEE (an organism linked to the IEC/http://www.iecee.org). As a reminder, this  organism has edited the recommendation documents about the tests to conduct in the framework of a certification extension IEC 61215, IEC 61646, and IEC 61730 (modification of one of the components).

For several years and thanks to its experience as accredited ISO 17025  laboratory, ELIOSYS proceeds to factory inspections for its customers in order to determine if the components used are in accordance with the certificate. It aims also to check if the best manufacturing practices are applied in the production plants, and so all over the world.

The output of a factory inspection is reflected in a technical report. This report is made up of a high number of points and finishes by an evaluation including preventive, improving, or immediate measures.

If the report doesn’t contain any comments with a serious impact on the quality of the modules produced, a factory inspection certificate and/or a local European manufacturing certificate will be issued. Every certificate delivered is published on the website of Eliosys allowing for a total transparency.



ELIOSYS will proceed to a complete inspection of the manufacturing plant.

Below, the list of the structured aspects along several axes which will be controlled in details.


  • The list of certified pv module(s)
    • Certified and uncertified models
    • Technology
    • Basic model tested
    • Specify differences between basic models and other models of the same product family
    • Production period of tested samples
  • Inspected production areas
    • Storage of materials/components
    • Production line and processes
    • Product Verification Tests
    • Quality Assurance
  • ISO 9000 CERTIFICATIONS details


  • Solar Cells
  • Electrical interconnections: cell connections, string connections, soldering material
  • Cell Encapsulation: encapsulation material, edge sealing
  • Superstrate and substrate: front cover, back cover, etc
  • Electrical components: junction box, cables, connectors, diodes
  • Mounting accessories: frame and others
  • Labeling


  • Cell Tabbing
  • Connection of Cells into Strings
  • Interconnection of Strings
  • Preparation of Layers (sandwich)
  • Lamination Process including curing details
  • Framing


  • Checking/Sorting of Cells
  • Intermediate Controls
  • Final Controls
  • PV-Module Process Monitoring


  • Premises and Environmental Conditions
    • Storage / Handling of Components/Materials
    • Production Areas
  • Incoming Goods Inspections
  • Tests and Calibrations (control of output power)
  • Documentation of Process Data
  • Handling of Defective and Non-Conforming Products
  • Customer Complaints
  • Changes to Certified Products
  • Warranty

Note: this list contains the basic elements for the factory inspection. According to the complexity of the company structure, the list of elements can slightly vary and be adjusted.

A certificate of factory inspection is valid for 1 year.

This certificate is linked to the product certificate ((IEC 61215, IEC 61646 and IEC 61730) in order to maintain a certain level of continuity in the assessment of a PV product. Indeed, a product certificate is established based on a sampling done by the manufacturer on his first production batch. In case of compliance with the requirements of the standards, a certificate is delivered with a validity of 5 years.

The main goal of the factory inspection is thus the control of the accredited product features in terms of their components (cells, frame, EVA …) and of production quality.

Depending on the size of the manufacturing plant, the control duration can vary from half a day to two complete days (without taking potential transportation into account).