The Built for India Edition

A module can clear standardised qualification tests and still face very different operating stresses from one site to another. India is not one operating environment. It is many. This issue looks at how site conditions can change which module characteristics deserve closer attention.

Insight: Matching specs to the environment

The Thar desert, the Konkan coast, the Gangetic plain, and the Deccan plateau can present very different combinations of heat, humidity, dust, rainfall, salt exposure, and other environmental stresses. The point is not that one region has a single fixed condition. It is that the operating environment should be part of the specification process.

At hot and dust-prone sites, operating temperature and soiling can influence energy yield and maintenance requirements. IEA PVPS identifies soiling as a site-dependent performance factor and recommends site-specific measurement and mitigation rather than a one-size-fits-all assumption. [5]

For coastal projects, salt-laden wet atmospheres may make corrosion resistance and sealing details more relevant. IEC 61701:2020 is specifically designed to evaluate possible PV module faults associated with salt-mist exposure in wet, salt-rich atmospheres. [3] Where agricultural or livestock environments create ammonia exposure, IEC 62716:2013 provides a dedicated ammonia-corrosion test framework for PV modules. [4]

The datasheet does not change between sites. The relevance of each line item can.

This is where matching a specification to a location becomes practical engineering work. Efficiency remains important, but depending on the site, temperature behaviour, encapsulation and sealing, corrosion resistance, soiling management, and mechanical loading may also influence module selection and long-term performance.

The IEC 61215 series provides the recognised framework for design qualification and type approval of terrestrial PV modules. IEC 61215-1:2021 also makes an important distinction: useful service life depends on module design, environment, and operating conditions, and qualification results are not a quantitative prediction of module lifetime. [1][2]

SLR Solar’s current Bifacial N-TOPCon G12R technical document lists dual-glass construction, a temperature coefficient of -0.30%/°C, and positions the product for applications including deserts, coastal regions and agricultural environments, subject to project-specific engineering evaluation. [8] These product specifications are most useful when read alongside the actual site profile rather than in isolation.

The practical takeaway for anyone specifying a project is simple: start with the site, then read the datasheet through that lens. The environment helps determine which specifications deserve the most attention.

From the floor: A question worth asking for coastal projects

Consider a project located close to a coastal belt. If the module has passed a standard damp-heat qualification sequence, is that enough information for the site? It is a useful baseline, but it may not answer every site-specific question.

IEC 61215-2 defines repeatable qualification test procedures for PV modules, while IEC 61701 addresses salt-mist corrosion more directly. [2][3] The distinction matters because a controlled laboratory stress and a real operating environment are not identical. IEC 61215 itself notes that field service life depends on design, environment, and operating conditions. [1]

For a coastal site, procurement teams can look beyond a single pass-or-fail result and ask what environmental stress was actually tested. Construction details such as encapsulation, sealing, junction-box protection, frame and connection design can also be relevant to the reliability discussion, depending on module design and installation quality.

Salt-mist qualification under the relevant IEC framework can provide a more directly relevant signal for saline exposure than damp-heat duration alone. The goal is not to treat one test as universally superior, but to understand what each test is designed to evaluate and whether it maps to the site.

That is a more useful way to read standards: not as a checklist that replaces engineering judgement, but as evidence that needs to be interpreted in context.

One thing worth knowing: Why sustained humidity deserves attention

Sustained humidity is one environmental condition worth evaluating carefully, particularly for coastal, riverine, and high-rainfall locations. Humidity, particularly when combined with elevated temperatures and prolonged exposure, can contribute to moisture ingress and material degradation depending on module design.

NREL research has modelled how different temperature and humidity profiles affect moisture ingress and material degradation in PV modules, reinforcing that climate exposure is not identical from one site to another. [6] IEA PVPS Task 13 also highlights encapsulation-related degradation and combined environmental stresses, including humidity and temperature, as part of the reliability discussion for current module technologies. [7]

These mechanisms can develop gradually and do not follow one universal timeline. That is why fixed statements such as “this appears in year five” are less useful than looking at the actual environment, material system, module design, and available qualification evidence.

For specification teams, the practical step is to consider humidity exposure alongside efficiency, temperature behaviour, mechanical requirements, and other site-specific risks. Ask about encapsulation and sealing. Check which environmental qualification tests are relevant. Then evaluate the evidence against the conditions the module is expected to operate in.

Efficiency matters at procurement. Matching module characteristics with the operating environment can contribute to long-term system reliability.

That is it for this issue. Build for the site you have, not the site a generic test condition assumes.

Sources & technical references

[1] IEC 61215-1:2021. Terrestrial photovoltaic (PV) modules - Design qualification and type approval - Part 1: Test requirements. International Electrotechnical Commission. IEC official publication

[2] IEC 61215-2:2021. Terrestrial photovoltaic (PV) modules - Design qualification and type approval - Part 2: Test procedures. International Electrotechnical Commission. IEC official publication

[3] IEC 61701:2020. Photovoltaic (PV) modules - Salt mist corrosion testing. International Electrotechnical Commission. IEC official publication

[4] IEC 62716:2013. Photovoltaic (PV) modules - Ammonia corrosion testing. International Electrotechnical Commission. IEC official publication

[5] IEA PVPS Task 13/16 (2025). Understanding, Measuring, and Mitigating Soiling Losses in PV Power Systems. IEA PVPS fact sheet

[6] Kempe, M. D. & Wohlgemuth, J. H. (2013). Evaluation of Temperature and Humidity on PV Module Component Degradation. National Renewable Energy Laboratory (NREL), presented at the IEEE Photovoltaic Specialists Conference. NREL publication record

[7] IEA PVPS Task 13 (2025). Degradation and Failure Modes in New Photovoltaic Cell and Module Technologies. IEA PVPS report

[8] SLR Solar. Technical Details - BIFACIAL N-TOPCon G12R. Current product technical document supplied for this issue.

Reference note: IEC standards describe qualification requirements and test procedures. They should not be treated as proof of product-specific certification unless the corresponding SLR test or certification documentation is available. Compliance with IEC standards should be supported by valid certification and test reports from accredited laboratories where applicable.