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Solar power systems are reliable and require minimum maintenance. There are no moving parts and technology is robust and proven over long time. However, regular inspection is recommended once a year. This is to maintain safety and high efficiency to earn profit from investment. Find out more below.
For residential solar rooftop systems, the solar audit usually consists of site visit with visual inspection and basic electrical testing. Possibly includes thermal scan and washing of solar panels.
However, for large scale commercial solar rooftop and solar park, it requires much more extensive solar inspection procedure following the industry standard IEC 62446-1 (or in Vietnam equivalent: TCVN 11855-1:2017).
The standard IEC 62446-1 Photovoltaic (PV) systems defines the minimum inspection criteria and documentation expected for safe operations of grid connected solar power system.
The equivalent technical standard in Vietnam is: TCVN 11855-1:2017 hệ thống quang điện (PV) – yêu cầu thử nghiệm, tài liệu và bảo trì – phần 1: hệ thống nối lưới – tài liệu, thử nghiệm nghiệm thu và kiểm tra
Does my solar energy system need solar inspection?
All solar energy system require regular maintenance check to make sure the solar power system operate in a safe way. However, regular maintenance check is less stringent than solar inspection in accordance with IEC 62446. The industry practice is residential solar power only need regular maintenance check while solar park and C&I commercial rooftop solar is recommended to have solar inspection IEC 62446.
What is the difference between normal maintenance check and solar inspection following IEC 62446?
Small solar power systems – only basic maintenance check is required. It includes a site visit, inspecting inverter, solar panels, structure, wires and others. This activity is usually limited to visual inspection and basic electrical tests. Also, some contractors offer washing and cleaning the solar panels. However, the documentation is less demanding and maintenance check tasks vary depending on company. This is suitable for small size photovoltaic systems such as residential solar. The reason for limited process is that small system is easier to inspect because it contains only a small number of components to check. And it saves time for the owner also who normally need to be in the house when inspector comes.
Large commercial systems is recommended for full solar inspection IEC 62446. Here you get a detailed report of the solar energy system condition. There are possibly thousands of components in a large system. Performing ad-hoc inspection can take a lot of time and may not be high quality. But the IEC standard can help to minimize the human error and maximise the inspection efficiency. Performing this work require personnel who are experienced and trained. It requires technical tools, demand extensive field testing, later expert analysis using technical software and possibly return to site again for more testing. Usually the following equipment is needed: special infrared drones, IR camera to evaluate the IV curve, insulation resistance tester, test solar cell with temperature sensor, PV string tester, Pdetector kit etc etc… This is suitable for solar park or commercial rooftop solar systems.
Which type of inspection/ maintenance is currently performed for my solar power system?
You should receive a report after your contractor performs site inspection. That report should contain similar check activities as our Suntiki IEC inspection report. If you have any question about the report you have received, you can always call a solar inspection company to ask for second opinion of the report.
What are the activities in solar inspection? In practice this means inspecting 3 important areas:
Some of the inspection components include:
Thermal Inspection: for effective visual inspection of thousands of solar panels. Possibly reaching to areas not easily accessible.
Visual Inspection: Test AC and DC circuits, earthing connection, polarity test, open voltage measurements, test to string configurations ….
Electrical testing (iv curve): technical analysis of IV curves.
Performance testing (pv cell): analysis of actual solar energy production compared to PV test cell installed in same conditions as the system.
Documentation: Technical analysis, risk mitigation/ repair plan.
We carry out a detailed technical inspection of solar power plant, which includes a comprehensive assessment of the technical condition of individual elements of the photovoltaic system (including solar modules, inverters, control panels, batteries and transformers). Quality control of a solar power plant is carried out under normal operating conditions under load and usually does not require extensive shutdown of equipment. We provide a detailed technical report with an expert opinion and suggestions for troubleshooting. We recommend conducting a scheduled technical inspection of solar power plants twice a year.
Special tools allow us to easily inspect your solar panels and pinpoint a large number of problems. The inclusion of thermal imaging checks in the planned maintenance of the solar plants will help the plant to work safer and increase its overall efficiency. Such an analysis is advisable to obtain more accurate information on the state of the solar modules at your solar power plant.
Solar inspection – why need the audit? A technical solar inspection will bring the following benefits:
Increase safety. Reduce fire risk. Reduce DC arc risks.
Increase investment profit. Maximise solar power energy production. Reduce electricity bill.
Prevent high cost equipment breakdowns.
Managing warranty claims with equipment suppliers.
+25 years exposed to sun, rain and storms:
Commercial solar energy systems are used for at least 25 years and more. They contain solar panels and wires that are exposed to all weather elements. Damages from the sun’s UV light, corrosion from the rain, physical damages from record windspeed storms, damages from rodents, substandard and reckless installation prioritise schedule more than quality are just a few issues on a long list. You can read more about fire protection standards here.
Equipment degrade over time, but how much?
It is well known any equipment loses its original efficiency over time. And so, when we see reduced pv production or increased electricity bill, how can we know if this is the expected performance or if something is wrong? Technical inspection and audit can provide accurate analysis of real state of operation for solar power plant and commercial rooftop installations C&I.
Lack of photovoltaic technical standard in new industry:
In fact, Vietnam solar energy industry is still very new and until now there are very few technical standards that EPC contractors must follow. And yet Vietnam has installed a record of 19,400 MWp by 2020 to become the ASEAN top installer.
Example where Solar Audit is needed:
In most cases, solar audit will increase the performance of solar power project. However, while accidents are very rare, the solar audit can prevent accidents, fires, building collapse and other quality issues. An extreme example is the Gia Lai solar energy system that caught fire and media attention in 09/2020. A rooftop solar system with 60 solar panels caught fire on the rooftop of Gia Lai Electricity Joint Stock Company.
The head of firefighting department suspect the issue is DC arc discharge from one of the 50 DC wire connections.
House owners – small system – only basic maintenance is needed.
Property owners with large scale C&I solar panels on rooftop need full IEC-62446
PPA and DPPA investors need full IEC-62446.
About the standard IEC 62446 – Technical standard for solar inspection.
IEC 62446-1:2016 Photovoltaic (PV) systems – Requirements for testing, documentation and maintenance – Part 1: Grid connected systems – Documentation, commissioning tests and inspection.
IEC 62446 defines the minimal information and documentation required to be handed over to a customer following the installation of a grid connected PV system.
This standard also describes the minimum commissioning tests, inspection criteria and documentation expected to verify the safe installation and correct operation of the system. The document can also be used for periodic retesting.
It is for use by system designers and installers of grid connected solar PV systems as a template to provide effective documentation to a customer. Include a wide range of system test and inspection regimes to encompass larger and more complex PV systems.
This standard is composed into 2 main parts:
The equivalent standard used for Vietnam is:
Tiêu chuẩn quốc gia TCVN 11855-1:2017 hệ thống quang điện (pv) – yêu cầu thử nghiệm, tài liệu và bảo trì – phần 1: hệ thống nối lưới – tài liệu, thử nghiệm nghiệm thu và kiểm tra
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Công suất điện: |
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loại/ công nghệ: |
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Công ty: |
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Số tài liệu. |
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Rev. | Description | Date | By | Check | Accept. | |
Project
| Document Technical Inspection/ Solar Audit Report following IEC 62446-1/ TCVN 11855-1:2017 | |||||
Suntiki Partnership:
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Suntiki in the news …
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A: Suntiki Solar Verification Certificate:
PV system verification certificate: | ð Initial verification. ð Periodic verification. |
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DESIGN, CONSTRUCTION, INSPECTION AND TESTING:
I/we being the person(s) responsible for the design, construction, inspection and testing of the electrical installation (as indicated by the signature(s) below), particulars of which are described above, having exercised reasonable skill and care when carrying out the design, construction, inspection and testing, herby certify that the said work for which I/we have been responsible is, to the best of my/our knowledge and belief, in accordance with ………………………………………………..
Signature(s): |
| The extent of liability of the signatory(s) is limited to the work described above: |
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Date: |
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Next inspection recommended after not more than: |
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B: Suntiki Solar Inspection Report:
PV system inspection report: | ð Initial verification. ð Periodic verification. |
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General
The entire system has been inspected to the requirements of IEC 60364-6 and an inspection report to meet the requirements of IEC 60364-6 is attached.
DC system – General
DC system – Protection against electric shock
DC system – Protection against the effects of insulation faults
DC system – Protection against overcurrent
DC system – Earthing and bonding arrangements
DC system – Protection against the effects of lightning and overvoltage
DC system – Selection and erection of electrical equipment
AC system
Labelling and identification
C: Suntiki Solar PV Array Test Report:
PV array test report: | ð Initial verification. ð Periodic verification. |
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String | String reference | 1 | 2 | 3 | 4 | … | n |
Module |
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Array parameters (as specified) | Voc (stc) |
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Isc (stc) |
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String overcurrent protective device | Type |
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Rating (A) |
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DC rating (V) |
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Capacity (kA) |
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String Wiring | Type |
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Phase (mm2) |
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Earth (mm2) |
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String test | Voc (V) |
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Isc (A) |
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Irradiance |
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Polarity check |
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Array insulation resistance | Test voltage (V) |
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Pos – Earth (MΩ) |
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Neg – Earth (MΩ) |
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Earth continuity (where fitted) |
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Array isolator | Rating (A) |
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Rating (V) |
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Location |
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Functional check |
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Inverter | Make and model |
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Serial number |
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Functioning OK |
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Comment: |
CT TNHH Suntiki Solar is a solar energy company based in Vietnam. We consult, survey, engineer and install rooftop solar panel systems for residential, commercial, industrial such as factories, farms, villas, industrial parks and others.
