Technical inspection of PV plants and battery storage
Independent experts for photovoltaics and battery energy storage systems (BESS) in Germany: acceptance, measurement, due diligence and warranty – from construction to operation.
Photo: DroneWize
Services at a glance
Acceptance and commissioning inspection
Inspection of the PV plant and storage system before acceptance or commissioning, based on DIN EN IEC 62446‑1 (VDE 0126‑23‑1) and DIN EN IEC 62933‑2‑1.
Technical due diligence
Technical project review when a PV plant, a battery storage system or a portfolio is acquired.
Inspection by measurement
String measurement, thermography and aerial images, insulation resistance, testing according to DIN EN IEC 62446‑1 (VDE 0126‑23‑1).
Construction progress monitoring
Inspection of construction progress to identify defects and deviations from the contract early.
End-of-warranty inspection
Making hidden defects visible while remedial work can still be demanded.
Technical asset management
Regular, independent inspection and evaluation during operation.
Acceptance and commissioning inspection
A thorough inspection is essential so that no defects or faults are overlooked at acceptance or commissioning. We inspect the PV plant and, where present, the battery storage system. You receive an expert report with a list of defects and an assessment of the documents provided.
Scope of inspection, PV plant
based on DIN EN IEC 62446‑1 (VDE 0126‑23‑1)
- visual inspection of the installation
- safety review of the plant
- earthing and equipotential bonding
- inspection of the mounting structure
- measurement of the string currents
- thermography, including by drone
- drone survey with aerial images of the module field
- comparison with the design documents
- review of the commissioning documentation
- check of the function of the plant monitoring
- further inspection items by agreement
Scope of inspection, battery storage (BESS)
based on DIN EN IEC 62933‑2‑1
- documentation and commissioning records
- system status of the BESS
- effectiveness of protective devices and switchgear
- energy management system (EMS) and connection to control centre and marketer
- capacity and efficiency test
- execution of the test cases developed with the client
- evaluation of the BMS logs
For storage systems we have been trained by several manufacturers, e.g. Commeo, ABB, Tesvolt, Varta and Kostal.
Technical due diligence (technical project review)
If a PV plant, a battery storage system or an entire portfolio is to be acquired, we review the technical aspects down to the plant documentation. We identify defects and assess the technical risks.
We also review projects at the planning stage, before construction starts: design documents, yield assessments and the technical content of the contracts.
Inspection by measurement
Measurements reveal defects and faults.
- string measurement
- I-V curve measurement
- thermography from the ground and by drone, plus aerial images
- insulation resistance measurement
- testing according to DIN EN IEC 62446‑1 (VDE 0126‑23‑1)
Construction progress monitoring
During construction we inspect the progress of the works on site, on dates agreed with you. Defects and deviations from the contract are thus identified early, and countermeasures can be taken.
End-of-warranty inspection
Until the warranty period ends, hidden defects can be reported and remedial work can be demanded. We make hidden defects visible and advise you on the possible steps.
Technical asset management (TAM)
For an unbiased condition report, it is advisable to have plants inspected from time to time by an independent party.
- regular and on-request inspections
- assessment of defects and their rectification by the O&M operator
- monitoring and evaluation of the plant yields
- preparation of reports
- advice on measures to increase yield
Frequently asked questions
What does the acceptance inspection of a PV plant cover?
The inspection is based on DIN EN IEC 62446‑1 (VDE 0126‑23-1): visual inspection of the installation, safety review, inspection of the mounting structure, measurement of the string currents, thermography and drone survey, comparison with the design documents, review of the commissioning documentation and of the function of the plant monitoring. Further inspection items are added by agreement.
Do you also inspect battery storage systems?
Yes. We inspect battery energy storage systems (BESS) based on DIN EN IEC 62933‑2-1: documentation and commissioning records, system status, effectiveness of protective devices and switchgear, energy management, capacity and efficiency test, test cases developed with the client and evaluation of the BMS logs. For storage systems we have been trained by several manufacturers, e.g. Commeo, ABB, Tesvolt, Varta and Kostal.
Which measurements do you carry out on existing plants?
String measurements, I-V curve measurements, thermography and aerial images, insulation resistance measurements and tests according to DIN EN IEC 62446‑1 (VDE 0126‑23-1). These reveal defects and faults.
Why inspect before the end of the warranty period?
Until the warranty period ends, hidden defects can be reported and remedial work can be demanded. We make hidden defects visible and advise on the possible steps.
What is checked in a technical due diligence?
When a PV plant, a battery storage system or a portfolio is acquired, we review the technical aspects down to the plant documentation, identify defects and assess the technical risks.
What does technical asset management provide?
An independent party inspects the plant regularly or on request, assesses defects and their rectification by the O&M operator, monitors and evaluates the yields and prepares reports. This gives an unbiased picture of the condition of the plant.
How long does a technical inspection take?
We agree the inspection date with you; the time frame for inspection and report is stated in the quote. If it is urgent, please contact us.
Enquiry
Use the form, call us on +49 4103 121 4221 or write to kontakt@sonnwinn.de – whichever suits you best.
You do not need to attach documents to your enquiry – once we have received it, we will help you put together the documents required.
Which documents are helpful
- Type and size of the plant, location and preferred inspection date
- Components (modules, inverters, storage) with data sheets
- Single-line diagrams, string plan and site plan of the plant as built
- Measurement and test records, e.g. string and insulation measurements and earthing system according to DIN VDE 0100‑600
- Commissioning and acceptance records, for storage systems also the test cases
- If available: access to the plant monitoring