Quality control in photovoltaic parks
Southern Europe has privileged conditions for the use of solar energy in the production of electricity via photovoltaic technology. Our country, in particular, has excellent sun exposure indicators and geographical areas suitable for the installation of large photovoltaic parks.
The reconciliation of these natural conditions of our territory with the increasingly prices competitiveness of the photovoltaic technology it turns the construction of large photovoltaic farms an attractive investment area for large national and international investors.
Due to this big potential market expansion for large photovoltaic infra-structures in Portugal it’s desirable that the expected evolution should be followed by a bigger and more sophisticated quality control of the constructions which also correlates a much more systematized performance evaluation for the photovoltaic production system.
In this context, three crucial stages of this evaluation are identified with different objectives:
- In the factory at the construction of photovoltaic panels;
- At the photovoltaic farm construction;
- And at the operation and maintenance stage.
The evaluation during the photovoltaic panel’s construction phase aims to validate the factory performed tests, both about performance as well as the construction quality at the factory’s exit.
The validation at the photovoltaic farm construction aims to verify and validate the performance indices of the photovoltaic panels before their installation, or even to identify damaged panels resulting from the transportation phase. With this procedure, if any fault is detected, it can be reported directly to the manufacturer, even before installation.
This procedure has two great benefits: on the one hand, it allows the installation team to be exempted from any responsibility during the assembly phase and on the other hand, it reduces the financial risk associated with the project resulting from a better overall performance of the photovoltaic park.
Last but not least, during the operation and maintenance phase, the evaluations of the panels performance that, correlated to the electrical infrastructure delivering capacity, it plays an essential role on the global energetic delivering capacity of the photovoltaic farm since this in way it’s possible to identify photovoltaic panels, or other elements, with below-expected production rates thus protecting the investor.
As performance analysis and general evaluation, it’s strongly recommended to perform tests that allow I-V curves drawing, thermography and electroluminescence imagery for being able to detect pernicious pathologies.
The execution of the I-V curves allows us to verify if the efficiency of the photovoltaic panels is adjusted to the one specified by the manufacturer. With regards to thermography and electroluminescence, these tests it should allow us to identify, several defects, namely: Broken Cells, Detached Fingers, Defective Diode, Heated Junction Box, Multiple Hot Cells, Single Hot Cell, Open Circuit Module, Shade and Soiling.
Therefore, in order to control the quality of the materials, in particular the quality of the photovoltaic panels, performance and defect detection analyzes are recommended during the process of building the photovoltaic plants and during the operation and maintenance period. Only by quantifying the deviations and potential problems will it be possible to intervene in order to maximize the efficiency of the photovoltaic energy production system by increasing the revenue produced by these systems, thereby contributing to the reduction of greenhouse gas emissions and maximizing the return on investments made.