# Increasing Photovoltaic Systems Efficiency Through the Implementation of Statistical Methods
## 2 Literature Review  
### Review of High-Performance Technologies for PV Cells and Modules  
Due to the exponential growth of industrial production, with significant implications for the development of energy sources and all types of transportation, there is an urgent need to reduce the carbon footprint. Therefore, most countries worldwide are interested in developing and optimising renewable energy sources: solar, wind, geothermal, hydropower, ocean energy, and bioenergy. The photovoltaic (PV) conversion provides the most outstanding development dynamics. According to the Clean Energy Technology Observatory [12], in 2022, the cumulative global installed photovoltaic capacity exceeded one terawatt (TW), while cumulative electricity generation from photovoltaic sources was approximately 158 terawatt-hours (TWh). Considering this dynamic, various equipment and processes use PV systems for an efficient power supply [13]. Despite certain shortcomings in solar energy conversion efficiency, it remains one of the most reliable and affordable energy sources, especially in remote areas. Its conversion can provide electricity to supply isolated households by ensuring the end-users' energy consumption and management of other potential various generation sources [14] or different equipment for monitoring environmental parameters or biodiversity protection, such as behavioural barriers associated with river water intakes [15].  
In theory, the maximum efficiency of a single junction p-n solar cell is 30% at 1.1 eV, but the maximum laboratory efficiency for a single junction is about 27%. At the same time,the efficiency of photovoltaic modules is lower than that of a PV cell due to resistive losses in the solar cells, as well as variations in individual solar cell efficiencies [16]. Although the conversion efficiency of hydroelectric power plants is around 90% and that of power plants is about 40%, both have a very low carbon footprint. Yet, a series of arguments plead for the priority of photovoltaic conversion [17; 18; 19]. First of all, solar energy is practically available everywhere, unlike hydroelectric power, and, relative to nuclear power plants, there are no radioactive residues. However, although PV systems have an almost zero carbon footprint, this can be significant if the manufacturing processes are taken into account [20; 21]. Additionally, extending the lifespan of PV modules and addressing waste management at the end of their lifespan have recently become significant concerns in the context of the circular economy. This concern becomes more pressing as the prospect of equipping photovoltaic power plants with lithium-based batteries becomes a requirement for efficiency. Therefore, recycling these devices will involve more significant challenges than recycling PV modules.  
The history of photovoltaic conversion will soon complete two centuries of existence, with its beginnings marked by the French experimental physicist [PERSON] in 1839. The progress in this field has been modest given that over the last half-century, we have witnessed an exponential increase in efficiency [16; 22]. Thus, nowadays, apart from technologies of the first-generation a-Si, c-Si mono and polycrystalline, there are envisaged superior efficiencies characterising the new technologies, even in the commercial field, as presented in Table 1:  
The table above should also include thin-layer cadmium telluride (CdTe) solar cells, which are the second most common photovoltaic PV technology after crystalline silicon, representing 21% of the U.S. market and 4% of the global market in 2022, with an efficiency of approximately 24%, and GaAs module technology with concentrators (Fresnel lenses), which can reach an efficiency of 28% [25; 26].