Renewable energy sources are critical to the global effort to achieve carbon neutrality. Alongside hydropower, wind and nuclear plants, the photovoltaic (PV) systems developed greatly, with new PV technologies emerging in recent years. Although the conversion efficiencies are improving and the materials used have a lower impact on the environment, the feasibility of these technologies is required to be assessed. This paper proposes a levelized cost of energy (LCOE) model to assess the feasibility of five PV technologies: high-efficiency silicon heterojunction cells (HJT), N-type monocrystalline silicon cells (N-type), P-type passivated emitter and rear contact cells (PERC), N-type tunnel oxide passivated contact cells (TOPCon) and bifacial TOPCon. The LCOE considers capital investment, government incentives, operation and maintenance costs, residual value of PV modules and total energy output during the PV system’s life span. To determine the influence of PV system’s capacity over the LCOE values, three systems are analyzed for each technology: 3 kW, 5 kW and 7 kW. The results show that the largest PV systems have the lowest LCOE values, ranging from 2.39 c€/kWh (TOPCon) to 2.92 c€/kWh (HJT) when incentives are accessed, and ranging from 6.05 c€/kWh (TOPCon) to 6.51 c€/kWh (HJT) without subsidies. The 3 kW and 5 kW PV systems have higher LCOE values due to lower energy output during lifetime.

In contemporary society, electricity has become one of the most prevalent energy sources, with a global distribution network. The significance of energy efficiency has become a prominent subject of interest across various disciplines, leading to a notable surge in research on electricity over the last decade. The present paper explores the significance of examining power losses in power grids and proposes methods to identify and reduce them. The objective of this study is to methodically and systematically review existing databases to identify relevant studies pertinent to electricity losses in power grids. To this end, this study methodically categorizes energy losses into two primary classifications: technical losses and non-technical losses. To this end, two primary analytical approaches have been devised, providing a foundation for the prioritization of the most effective detection methods for each loss category, as well as the most recent findings in the literature on reducing these losses. The issue of power grid instability, stemming from fluctuations and voltage dips, was addressed, with power losses emerging as the primary source of concern. To this end, a comprehensive analysis of major academic databases, including Scopus, Web of Science, IEEE, and Google Scholar, was conducted to identify relevant research articles. This review introduces several important concepts for the energy field by introducing and analyzing the most relevant methods to identify and reduce power losses. The results of our study outlined the comprehensive analysis of 90 relevant studies on the benefits as well as the barriers encountered in the application of methods to identify and reduce electricity losses and the impact they have in the field under review. In conclusion, this paper emphasizes the importance of the in-depth study of the energy domain to achieve performance and contribute to the improvement of power grids. Future research directions are based on the implementation of artificial intelligence (AI) algorithms to achieve this goal.

Nowadays, as the technology behind solar photovoltaic systems has been significantly improved, along with a significant decrease in costs, grid-connected photovoltaic systems are becoming an important option to reach a low-carbon energy transition. The high cost of electricity consumed at the Technical University of Cluj-Napoca represented a good reason for the university to increase its energy efficiency by adopting and increasing energy consumption from renewable energy sources. This paper assesses the technical, economic, and environmental feasibility of deploying four photovoltaic systems at the aforementioned university situated in the Northwestern part of Romania, according to the Romanian renewable energy legislation. PVSOL software has been used to estimate the performance of photovoltaic installations. The results indicated that the most viable distributed generation system is the one with a capacity of 100 kW, meeting approximately 23 percent of university electricity needs, and at the same time, reducing carbon dioxide emissions by approximately 460 tons. A sensitivity analysis has been performed to evaluate the effect of several critical parameters on the PV system’s economic feasibility. The results provide valuable decision-making information regarding the buildings’ solar potential for other universities, supporting the transition to solar energy.

There are numerous and different ways to design an energy efficient street lighting system, but not always the best technical solution is the optimal economic solution as well. In this paper, we used two distinct software tools in order to obtain the optimal technical and economic solution for selecting street lighting technology. The first software used was DIALux, which is frequently applied in this field, assisting designers in choosing the most appropriate electrical installations and evaluating the technical performance of the chosen solutions. This tool determined the street lighting system variants for which there are predetermined configurations, so that the lighting parameters obtained are in accordance with the normative requirements of the lighting classes in which the roadways are included. Different ways of locating the luminaires and other parameters were changed to reach the best version that meets the qualitative requirements of the lighting technology. The second software used was the one developed by the authors, based on ELECTRE III method, which evaluated the technical solutions returned by DIALux against several criteria, taking into account the designer’s preferences and constraints. The optimal technical and economic solution was obtained after ranking the variants by their performance at each criterion. The simulation experiment and the results returned suggested that the combination of the two software tools is comprehensive and effective and it can be used in this type of decisions at large scale.

Nowadays, lighting industry can contribute to a more sustainable future, by reducing the total consumption of electrical energy used to illuminate indoor and outdoor spaces. Thus, lighting system design is one of the important components when thinking about building sustainability. Taking into account the final purpose of the lighting installation (the type of human activity that will take place in the indoor space for which lighting is to be provided), the most suitable lighting technologies are selected considering their characteristics, dimensions, and technical specification. The paper presents how a lighting technology selection for a production hall using a multi-criteria decision making approach. There are considered the most common luminaires and lamps which can assure the illuminance necessary for the hall, which represent the variants, evaluated against several criteria, considering the decision maker’s preferences and constraints. The variants are ranked according to their performance for each criterion. The optimal lighting solution obtained after the simulation experiment suggests that ELECTRE III method is a practical decision-making model that can be considered for this type of decisions.

Grid-connected residential rooftop photovoltaic systems with battery energy storage systems are being progressively utilized across the globe to enhance grid stability and provide sustainable electricity supplies. Battery energy storage systems are regarded as a promising solution for overcoming solar energy intermittency and, simultaneously, may reduce energy expenditure by minimizing grid exports or maximizing solar electricity self-consumption by households. This chapter aims to assess the feasibility of six lithium-ion and lead-acid batteries with different capacities connected to a grid-connected rooftop solar photovoltaic system for a dwelling situated in the north-western part of Romania. The results pointed out that the most viable option is the photovoltaic system combined with the 16.8 kWh lead-acid battery, generating an additional value of almost $18,000 USD over the investment’s lifetime. The results provide important decision-making information as regards the viability of grid-connected photovoltaic systems combined with different battery energy storage system technologies.