The check-up service is offered to owners and conductors of photovoltaic plants.
The check-up is fundamental because the power of the photovoltaic plants varies instantaneously according to different meteorological variables; it is therefore impossible to determine whether the functioning of the plant is correct or incorrect, based only on the production data.
The checks are therefore aimed at identifying any failure, malfunction or potentially harmful situation with the maximum timeliness, so as to intervene and keep the systems constantly in maximum performance.
The activities are carried out by experienced graduates technicians, who make use of certified and calibrated instrumentation. Each activity performed in the field is completed with a desk phase and with the issuance of a survey report.
The report has these purposes:
The service comprehends the following activities, which may be executed integrally or modulated based on the requests:
The activities are carried out by qualified and trained personnel.
The instrumentation used is equipped with all the necessary certifications and has, at the time of use, a valid calibration. In particular, the specifications for the implementation of the various activities are as follows:
The thermographic report presents a list of detailed anomalies observed with the thermal imaging camera.
Information are gathered in synoptic prospects that immediately return the condition of the plant. Here we show an example of a few prospects, from a real cluster of plants:
N° of modules with thermal anomalies
Note that for each anomaly all position information (layout reference), serial number and type of anomaly/defect are reported.
Position: 7° sail; 4° high panel from east
Deficiency: substring of warmer cells (ΔT= 3-5°C). Highlight on a light overheating on the juncture box of the panel due to the power dissolved by the bypass diode in conduction.
Position: 26° sail; 22° high panel from west
Deficiency: warmer single cell. Thermal anomaly connected to drops for “mismatching” in the cell. The defective cell is forced into reverse polarization by heat dissipating part of the power generated by the remaining cells.
Notes: the areas of the panel with thermal anomalies were examined using the temperature profile reported in the margin of the thermogram. The cold areas visible in the thermograms represent the supporting structures of the FTV generator.
The presentation report shows the result of the accomplished survey of the performance:
The energy efficiency of photovoltaic generators is verified in accordance with the requirements of M.D. 19/02/2007 and of the CEI Guide 82-25 and s.m.i..
The verification is carried out in the presence of an irradiance on the modules plan higher than 600 W/m2.
The output consists of a table that shows, in addition to other quantities, the value of the instantaneous PR of each subfield associated with an inverter or inverter drawer. Here is an example of a real cluster:
If the PR is under 80%, there is a problem regarding the subcamp which must be examined.
These checks are carried out on a sample of photovoltaic modules thanks to a special tool.
For each panel examined the power values measured under the test conditions, translated into STC conditions according to IEC/EN 60891, are compared with the nominal data declared by the manufacturer.
In particular, each manufacturer offers a guarantee on the performance of the modules for a period of 25 years. Typically the modules are guaranteed for a decay of 10% of the nominal power in the first 10-12 years and 20% per year.
Thanks to this verification it is possible to measure accurately the current-voltage characteristic of the module bringing it back to standard conditions and compare it with the expected decay. If the difference between actual and expected decay is greater than the guaranteed one, it is necessary to deepen the causes and the opening of the warranty claim with the module manufacturer.
Below is an example of a sample of real modules. It should be noted that for the determination of the variance, acceptable if less than 10%, the modules under investigation have peak power of 230Wp.
*In order to determine the temperature of the module, the ECT function (Equivalent Cell Temperature) has been used, according to the regulation CEI EN 60904-5.
In order to carry out these tests, it is not necessary to disable the plants.
Test reports are intended to clearly indicate where action should be taken to restore optimal operating conditions.
It must be considered that, for the way a photovoltaic system is made, a problem of under-performance on a module affects the entire string, which means it leads to under-performing also the other 15-19 modules electrically connected to it.
For more complex problems or for different needs, the services described can be complemented by other custom checks, such as:
The recommended frequency of verification shall be annual. It is possible to structure and agree multi-year monitoring plans with considerable advantage for the Customer.
Yes, we are able to provide customer support throughout the country, thanks to our branches in Pavia, Vicenza and Rome – in Italy – , while we are Active on the rest of the market with our branch in Bellinzona, Switzerland.
Yes, our work is “tailor made”. We provide a service built upon the requests of every company.
Each activity is managed by a Project Coordinator, who will be the interface of the Customer; that is a technical profile with a wide experience on the topic of interest. We never use call centers, only qualified personnel.
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