## 2 Materials and Methods
### PV Module Technologies Description  
In recent years, there have been several emerging PV technologies with higher efficiency and lower costs that dominate the mass production of PV supply chains [14]. All commercial PV module technologies reached conversion efficiencies over 20%, being used in numerous applications, including residential and commercial buildings, off-grid power and spacecraft [15]. One of those technologies is HJT, which is known for low temperature coefficient, superior open circuit voltage and reduced wafer thickness. Considering their structure, these modules have a streamlined production process, which involves fewer manufacturing operations leading to lower production costs and material usage [16]. As presented in Table 1, the efficiency of HJT technology varies between 21.6-25.6%, with a lifetime of 30 years. However, the life span can be affected by their ultraviolet (UV) irradiation and humidity sensitivity, which can worsen the annual degradation rate of HJT modules [16]. N-type technology has a conversion efficiency of 21-23.1%, and a lifetime around 25-30 years, as shown in Table 1. These characteristics are closely related to oxygen and carbon concentration and metallic impurities. An increase in oxygen content gradually decreases the lifetime of silicon material. Moreover, the metal impurities may form a recombination center which decreases the minority carrier lifetime of monocrystalline silicon. Other characteristics include low efficiency degradation, high impurity tolerance and opportunities for conversion efficiency enhancement [17]. PERC cells main feature is the back dielectric passivation with local contact openings to reduce surface recombination and increase light absorption. In recent years, PERC technology made significant progress by improving their performance, with the silicon wafer reaching over 20% efficiency in mass production, as seen in Table 1. However, to sustainably implement this technology, alternative manufacturing processes are evaluated to reduce production cost as well as enhance their conversion efficiency by over 22% and increase module power. Even though their life span reaches only 25 years, PERC modules perform better in high temperatures and low-light conditions [18]. TOPCon technology represents great interest due to their structure, since the wafer is not in direct contact with the metal. Its structure includes an ultra-thin silicon dioxide layer and a polycrystalline silicon layer, which form together a \"tunnel oxide passivated contact\", facilitating efficient extraction of charge carriers and reduces recombination losses, by boosting conversion efficiency. The commercial TOPCon modules can reach an efficiency of 22.8%, while laboratory modules can achieve over 25% efficiency, which demonstrates a great advancement of passivation technology. However, there are several challenges that this technology confronts with, like high impurities concentration and defects at the semiconductor/metal interface [19]. Bifacial cells have a structure made from transparent substrates, with a front-side p-n junction and a rear-side surface with metal contacts and an emitter, which maximizes the light collection. This ensures higher efficiency [20]. Moreover, their design permits them to absorb more light from front and rear surfaces, resulting in an increased energy production. Bifacial technology is particularly useful in environments with high albedo coefficient (reflectivity), ground-mounted and rooftop systems and elevated structures [21]. Bifacial TOPCon technology can reach 23% efficiency and a lifetime of 30 years, according to Table 1.  
Each presented PV module technology has its own advantages and disadvantages. By comparing their technical characteristics, it can be observed that the most efficient PV module technology is HJT, with a conversion efficiency that can reach 25.6%. It is followed by N-type and bifacial TOPCon modules, with efficiencies that are around 23%.