Metrology for biofilm identification in extreme environments: a case study on solar panel inhabiting fungi

Humanity's impact on the environment is profound, and the emergence of new manmade entities, the technosphere, has added a new layer of complexity to the environment by offering new niches to the biosphere. To study the emerging interactions between technosphere and biosphere and to mitigate anthropogenic impacts on one hand and the effects of the biosphere on the technosphere on the other hand it is crucial to develop dedicated methods and collect scientifically sound and quantitative data. One of the growing markets worldwide with a significant contribution to the technosphere is photovoltaics (PV). The use of solar energy is the fastest growing source of renewable energy in the EU. However, maintaining the efficiency of PV modules is crucial, as they are vulnerable to the accumulation of dust, other particulate matter, and subaerial biofilms (SAB) that can significantly reduce their efficiency. The accumulation of SABs is particularly problematic and accurate identification and detection of the core organisms forming biofilms is needed to devise effective mitigation strategies. Bioreceptivity, which refers to a building material's ability to be colonized by living organisms, is a crucial factor in SAB formation on PV modules. SAB is difficult to remove and can exacerbate the level of overall soiling, resulting in a reduction in energy conversion efficiency of more than 10%. Melanized ""black rock""-inhabiting fungi are the predominant members of SAB on PV modules exposed to ambient conditions, as they have adapted to survive in subaerial biofilm communities on desert rock surfaces. These fungi have resistance mechanisms such as growing as microcolonies, which are prevalent on subaerial biofilms that form on solar PV modules. Recent studies suggest that the rock-inhabiting fungi and other members of solar PV module communities are selectively adapted to withstand desert-like conditions on the glass surface rather than simply accumulating through atmospheric deposition. However, knowledge of biofilm composition is limited, hindering improvements in material development of surface glass used for solar modules and in strategies to prevent biofilm formation and cleaning of PV modules. Molecular biology approaches such as targeted molecular testing and nucleic acid sequencing have provided faster and more reliable identification of specific black rock-inhabiting fungi species or strains, but generating accurate and comparable measurements in different laboratories is a challenge. The FungiMET project seeks to develop and evaluate a reference measurement procedure(s) for the identification and detection of extremophilic fungi inhabiting PV modules as a basis to develop unified strategy for monitoring biofilm formation on PV modules, support management and control, and ultimately help define measures to prevent biofilm formation on PV modules. In the long run, the project will also help define measures to reduce water and soil pollution by reducing the need for cleaning agents for PV module maintenance. A well-established reference measurement framework will be developed, which is universally applicable in all climates and on all continents and will support research of biosphere in different environments as well as the spread of renewable energy not only in developed countries but also in developing countries