Novel Characterisation for Manufacturing and In-Field Performance (PP5.6)
PP5.6: Novel Characterisation for Manufacturing and In-Field Performance
As photovoltaic electricity generation enters the Terawatt scale, routine inspection of PV systems becomes increasingly important to detect and identify faults before, during and after installation, or as they arise during operation in the field.
Such inspections ensure (a) minimum investment risk, (b) maximum reliability and longevity, and (c) maximum yield (power produced) of the power plants. Common techniques that are used for the examination of fielded PV systems, include current-voltage (I-V) measurements, visual assessment, ultraviolet (UV) fluorescence imaging, thermal infrared (IR) imaging, and luminescence imaging.
Each of the methods has specific advantages and disadvantages.
Electroluminescence (EL) and photoluminescence (PL) imaging can provide spatially resolved images of a large variety of defects and loss mechanisms, such as recombination active defects, shunts, series resistance, and micro-cracks. Various luminescence imaging-based techniques for module inspection in the field have been demonstrated, some of them are used commercially, albeit on a very limited scale.
This work package aims to develop novel characterisation techniques, mainly to monitor in-field performance, but also for the manufacturing of a large-scale PV. A significant aspect, apart from the development of the associated methods and systems, is the development of a systematic approach for applying these techniques in routine operation and maintenance, with a view to optimise the performance of PV systems, while keeping the associated extra costs at a minimum.
Status at ACAP
Over the last three years, ACAP researchers have developed several novel outdoor PL imaging approaches that address the limitations and restrictions of existing methods. They enable outdoor PL image acquisition of field-installed solar modules operating in full daylight. These innovative concepts have already received significant attention from academia and have also attracted early interest from the industry.
Three approaches have been developed and successfully demonstrated so far;
Contactless switching of single modules: This method can be applied at any location in a large solar farm and, very importantly, no modifications to the system wiring are required.
Optical PV string modulation: the toggling of the operating point of an entire string is achieved via up to five optical modulators that are placed on modules connected to the same string, significantly speeding-up the imaging process.
Ultra-narrow bandpass filtering: taking advantage of highly absorbing atmospheric water vapor lines that overlap in a very narrow wavelength range around 1,135 nm, almost completely blocking the sunlight at the earth’s surface enables high-quality outdoor PL images with a single camera shot.
Further development of all three methods towards commercial readiness. This will include;
integrate PL imaging systems with unmanned ground-mounted or aerial vehicles.
investigate the combination of different measurement methods into one platform
develop and test machine learning approaches to analysing data for faults.
detailed cost/benefit comparisons between methods
developing new standards for outdoor inspection of large PV power plants in Australia
This work package will benefit tremendously from the strong links between ACAP researchers and industry partners across the entire PV value chain, including the relevant stakeholders who have an interest in module quality and reliability testing, such as module manufacturers, EPCs, system installers, companies providing inspection solutions and specialised companies.
Investigators: UNSW – Ziv Hamieri, Thorsten Trupke, Oliver Kunz