Understand hidden PV asset risk before acquisition, refinancing, or portfolio review

When you are buying, refinancing, or reviewing an operating solar PV asset, you need more than a surface-level view of the site. The system may look operational while still carrying hidden module damage, thermal anomalies, electrical faults, or installation-related issues that affect performance, safety, warranty position, or long-term asset value.

Technical due diligence field testing helps you assess the real condition of a PV asset before a transaction or investment decision. The goal is to identify risk early, focus follow-up where it matters, and create evidence that can be explained to owners, investors, lenders, and technical advisors.

When this inspection helps

  • You are buying, refinancing, or reviewing an operating solar PV asset.

  • You need field evidence before an acquisition or investment decision.

  • You want to identify hidden issues that may not appear in standard site documentation.

  • You need to understand whether anomalies are isolated or repeated across the asset.

  • You want full-site screening with targeted follow-up where higher-risk areas are found.

  • You need a repeatable inspection approach across one site or a portfolio.

  • You need findings mapped clearly by string, inverter block, site grid, GPS, or plant convention.

Why diligence testing is different

In operating plants, you often do not have a perfect baseline. Factory records may be incomplete. Past inspections may have used different methods. Site conditions may have changed over time.

That makes the inspection plan important. Technical due diligence should be broad enough to identify asset-level patterns, but focused enough to remain practical at site or portfolio scale.

The right scope may combine full-site screening, sample-based high-detail testing, and targeted electrical checks where the initial findings point to higher risk.

How we decide the right scope

The final inspection plan depends on the asset, the transaction context, and how the results will be used.

  1. What decision needs to be supported?

    Due diligence may support acquisition, refinancing, portfolio review, or internal asset risk assessment. Each use case may require a different level of documentation, sampling, and reporting.

  2. What level of site coverage is needed?

    For technical due diligence, broad site screening can help identify thermal anomalies, affected areas, and recurring patterns. This can guide where higher-detail EL testing, IV curve tracing, LBPD testing, or electrical checks are needed.

  3. Where should high-detail testing be focused?

    Not every diligence review needs high-resolution testing of every module. EL testing can be sampled or targeted based on the asset risk, site layout, inspection objective, and findings from broader screening.

  4. Are electrical risks part of the diligence question?

    If the concern includes string behavior, bypass diode risk, insulation issues, connector problems, combiner boxes, or other field hardware, electrical testing may be added to the inspection plan.

  5. What triggers targeted follow-up?

    The inspection plan should define what happens if screening or sampling shows higher-risk areas, repeated patterns, or unexpected findings. Those triggers help avoid ad hoc decisions during fieldwork.

  6. How should findings be mapped?

    A diligence report needs to be usable by both technical and commercial stakeholders. Before fieldwork starts, it helps to agree how findings will be reported: by string ID, inverter block, site grid, GPS location, or the asset’s existing naming conventions.

What we may test

Technical due diligence field testing needs to be broad enough to identify asset-level patterns, but focused enough to remain practical at site or portfolio scale. Intertek CEA may combine EL testing, infrared thermography, IV curve tracing, visual inspection, LBPD testing, and BOS / electrical field testing.

Method What it helps identify When it is useful
Electroluminescence (EL) testing Hidden cell cracks, inactive cell areas, internal module damage, interconnect issues, and other cell-level defects that may not be visible from the outside. Useful when technical diligence needs high-detail module evidence, especially where hidden module damage may affect asset value or warranty position.
Infrared (IR) thermography Hotspots, thermal anomalies, affected modules or strings, and plant-wide thermal patterns. Useful for broad site screening and for locating areas that may require closer follow-up.
IV curve tracing Electrical performance behavior of selected modules, strings, or sample groups. Useful when the diligence review needs to check whether parts of the system are producing as expected.
Visual inspection Visible module damage, glass breakage, frame damage, connector issues, wiring concerns, installation issues, corrosion, soiling, shading, and other site-level observations. Useful as a first-level condition check and for confirming visible issues that may affect performance, safety, or maintenance planning.
Lost Bypass Diode (LBPD) testing Lost or defective bypass diode behavior that can remain hidden during routine inspection and may create hotspot risk under shading. Useful when hidden bypass diode risk needs to be assessed as part of the asset review.
BOS / electrical field testing Wiring, connector, combiner box, insulation, string-level, or other balance-of-system electrical concerns. Useful when diligence questions involve electrical safety, abnormal string behavior, or field hardware issues.

The exact method mix depends on the diligence objective, asset size, operating status, site access, available records, and whether the findings need to support acquisition, refinancing, portfolio review, or internal risk assessment.