On Friday 13th of October, Marija Vukovic Defended her PhD thesis on “ Toward monitoring of photovoltaic power plants with photoluminescence imaging “.

Marija Vukovic has, through her PhD work, contributed to advancing the frontier of outdoor photoluminescence imaging of solar plants. This was exemplified through a featured article in Applied Physics Letters.

“From my perspective, she has paved a new path towards the use of outdoor PL in large-scale facilities, which is very intriguing to work on further.” Professor Ingunn Burud, Marija’s supervisor.

Summary of the work

By 2027, photovoltaic energy is set to dominate the global power landscape. Solar photovoltaic electricity generation, especially at a utility scale, is becoming the most cost-effective option for new power generation in many countries. To ensure the efficiency and reliability of solar plants, accurate fault detection is crucial.

Traditionally, faults in solar modules are detected through electrical measurements, but a more efficient and accurate method is emerging – photoluminescence imaging. This technique captures radiation emitted when charge carriers recombine in solar cells upon exposure to light. However, challenges arise when sunlight interferes with the emitted photoluminescence signal.

Together with her colleagues at NMBU, she has tried to develop an approach for photoluminescence imaging which would enable imaging of as many modules as possible with as little interference as possible for an easier implementation on a utility-scale photovoltaic power plant. This has been done by using the capabilities of a string inverter to change the operating point of a string. The first approach is based on remote control of the operating point between two conditions. The second approach is far less invasive and takes the advantage of the string inverter’s built-in functionality to conduct current-voltage curve sweeps. Both approaches enable variation of the operating point on more than one string.

A key innovation in Marijas work is a novel algorithm for real-time, unsupervised image processing, even in low irradiance conditions. This approach holds great promise for large-scale solar plant inspections, paving the way for more efficient and cost-effective fault detection as solar power continues to lead the way in the energy sector.

Marija is now continuing her career as a researcher at the Solar Power Systems department at IFE.