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Due to its simplicity, the one-diode model is commonly used for modeling the operation of photovoltaic (PV) modules at standard test conditions (STC). However, its inherent implicit nature often presents challenges in modeling PV energy production. In this paper, the innovative explicit one-diode model developed by us over time is adapted for estimating PV power production under real weather conditions. Simple yet accurate equations for calculating the energy output of a PV generator equipped with a maximum power point tracking (MPPT) system are proposed. The model's performance is assessed under various normal and harsh operating conditions against measured data collected from the experimental setup located at the Solar Platform at West University of Timisoara, Romania. As an application of the new equation for maximum power, this paper presents a case study where the energy loss in the absence of an MPPT system is evaluated based on atmospheric and sky conditions. [ABSTRACT FROM AUTHOR]

A solution to increase the electrical output of the photovoltaic systems relies on solar tracking mechanisms that increase the amount of received solar energy. The experimental results obtained during a monitoring period of one year are comparatively presented in the paper for five types of photovoltaic modules installed on a fixed platform (as reference) and on a dual-axis solar tracking platform in the Renewable Energy Systems and Recycling R&D Centre of the Transilvania University of Brasov, Romania. The influence of the solar-tracking mechanism and the meteorological conditions specific to the four seasons during the monitoring period on the output of the analysed photovoltaic technologies are discussed in the paper. The solar tracking increases by 28% the amount of the yearly received solar energy and by 29.6% the electrical energy output of the entire PV platform. The solar conversion efficiency of the tracked PV platform is slightly increased (14.34%) when compared with the fixed one (14.17%). When assessing the influence of solar tracking on each type of PV, the results show that the CIGS PV module has the highest relative energy gain (34%) followed by CIS (30.8%), m-Si (30.6%), p-Si (27.3%) and CdTe (23.4%) PV modules. [ABSTRACT FROM AUTHOR]

In this paper, using data from Romania, we analysed the changes in electricity consumption generated during the COVID-19 crisis, and the measures taken against the spread of the coronavirus to limit the effects of the pandemic. Using a seasonal autoregressive econometric model, we found that, beyond seasonal (weekly, monthly, quarterly, yearly) effects, the average daily electricity real consumption in Romania, during the state of the emergency period (16 March 16 to 14 May 2020) decreased by −194.8 MW (about −2.9%), compared to the historical data (2006–March 2022), and this decrease is not due to the action of some random factors, and it is not a manifestation of domain-specific seasonality. The literature discusses the hypothesis that during the pandemic time, the profile of daily electricity consumption on weekdays was close to the typical Sunday profile. We tested a similar hypothesis for Romania. As a methodology, we tried to go beyond the simple interpretation of statistics and graphics (as found in most papers) and we calculated some measures of distances (the Mahalanobis distance, Manhattan distance) and similarity (coefficient of correlation, cosines coefficient) between the vectors of daily electricity real consumptions, by hourly intervals. As the time interval, we have analysed, for Romania, the electricity real consumption over the period January 2006–March 2022, by day of the week and within the day, by hourly intervals (5911 observations). We found (not very strong) evidence supporting a hypothesis that, in the pandemic crisis, the profile of electricity consumption approaches the weekend pattern only for the state of the emergency period, and we could not find the same evidence for the state of the alert period (June 2020–March 2022). The strongest closeness is to the hourly consumption pattern of Saturday. That is, for Romania, in terms of electricity consumption, "under lockdown, every day is a Sunday" (Staffell) it is rather "under lockdown, every day is (almost) a Saturday"! During the state of the alert period, consumption returned to the pre-crisis profile. Since certain behaviours generated by the pandemic have been maintained in the medium and long term (distance learning, working from home, online sales, etc.), such studies can have policy implications, especially for setting energy policy measures (e.g., in balancing load peaks). [ABSTRACT FROM AUTHOR]

This work focuses on a very important and current problem in the gas field: gas losses in natural gas distribution networks and their impact on the environment, as well as on the company operating the network. The paper starts with a bibliographic study and aims to identify the sources leading to losses, estimate loss volumes, reduce these losses by replacing high-risk pipeline sections, as well as trace the economic, environmental, and social impact. The calculation methodologies used in various countries in estimating these consumptions are very diverse. Romania uses a very dense methodology that can prompt very broad variations in the values obtained for technological consumption calculations using Order 18/2014, due to the multitude of parameters that must be estimated. To reduce some of the uncertainties in estimating these parameters, a study was proposed and carried out on the ill-fittings in the natural gas distribution systems. The article presents the experimental stand, the analysis of the experimental data, the methodology for calculating gas losses in the natural gas distribution system through leaking equipment, as well as the results obtained and the conclusions. Moreover, an application was made for a dynamic area check of the gas balance. Based on the correlations between the annual values in M&R stations, AMR, the volume for small consumers, technological consumption, linepack, and the equipment and materials used in the network, useful data were obtained in the diagnosis of problem areas. The end of the paper shows an economic calculation regarding the replacement of problematic pipeline sections in natural gas distribution networks. The difference between the volume of investments and the income from loss reduction is very large, but the aspect of protecting the environment and eliminating technological risks intervenes, thus increasing social security and health. [ABSTRACT FROM AUTHOR]

The energy transition is a subject of significant interest in the countries of the European Union, and the involvement of public authorities is remarkable. Unlike previous energy transitions, this process is politically driven, the efforts of public authorities being secondary to the actions of companies whose guidelines are based on stability at the European level through strategies and directives. This paper aims to provide an overview of the current evolution of energy security status in the European Union and in Romania, with reference to global efforts to achieve climate neutrality through the energy transition. The historical method was used in the elaboration of the material, in order to outline the current energy security policies in terms of sustainability, both environmental and social. The logical method was used in order to emphasize the cause–effect relationship between economic processes in the energy sector. The use of bibliometric analysis demonstrated the importance of the topic of energy transition in scientific literature, but it also demonstrated the increasing interest of researchers in subjects related to energy security and energy poverty in the context of this new transition. By using the graphical method, statistic data and their evolution were highlighted in detail for the present study. The results of the articles are embodied in an approach that aims to focus on economic and social factors that determine the capacity of states to support the EU's independence from a single supplier in the current context of conflict. The authors conclude by anticipating massive challenges in achieving the environmental objectives of the European Green Deal, as well as by highlighting the issue of energy poverty as a social factor influencing global strategic decisions. [ABSTRACT FROM AUTHOR]

Worldwide, in the rotary kilns of cement plants, various amounts of combustible waste are burned, which would otherwise end up in municipal landfills. The paper first analyzes the literature on the co-processing of waste in cement manufacture and its influence on the environment and human health. Then, it shows how the combustion components of co-processed waste can influence the final characteristics of clinker and cement. The main objective of the paper is to determine the level of emissions of the resulting pollutants (total dust and flue gases: NOx, SO2, and CO) at the outlet of the chimney of the clinker kiln and flour mill to meet the requirements of the Integrated Environmental Permit (EIA) from Romania and present an estimation of the level of atmospheric air pollution using the climatological model of pollutant dispersion. Following these assessments (data shown), the cement factories will establish measures to reduce the pollution, if necessary, to comply with the regulations in force for the cement industry. [ABSTRACT FROM AUTHOR]

Off-grid hybrid renewable energy systems represent the most modern and flexible solutions that can cover a wide range of energy efficiency needs for household consumers. In the current context, these systems must be taken into account by most household consumers, given the fact that the price of energy has increased. This paper proposes an experimental analysis of the behavior of such a system, in real operating conditions, considering two renewable energy sources, wind and photovoltaic sources, using an experimental stand. It can be considered a testing platform for hybrid energy production systems, in that the power installed in the two sources can be scaled up. The platform has the advantage of allowing the implementation of different load and wind curves through a programmable logic controller; in this way, it is possible to evaluate the degree of coverage of the energy consumption produced from renewable sources, in the north-east of Romania, in the Suceava County region. The experimental study also involves an analysis of the storage capacity in relation to the consumption and the electricity produced by the two renewable sources. In this regard, three scenarios differentiated by the state of charge (30%, 50% and 70%) have been established. The results indicate that, for each of the imposed scenarios, the energy required to cover consumption is produced by renewable energy sources (42%, 47% and 53%), to which the energy stored in batteries (39%, 28% and 18%) is added. [ABSTRACT FROM AUTHOR]

The authors compare the energy consumption and CO2 emissions from vehicles using internal combustion engines (ICE), battery electric vehicles (BEV), fuel cell electric vehicles (FCEV), and two types of hybrid vehicles, BEV-ICE hybrid and BEV-FCEV hybrid. This paper considers several scenarios for four countries' electricity production from primary energy sources to estimate total CO2 release. Energy consumption of the vehicle per 100 km, emissions during manufacturing, battery production, and lifecycle of the vehicle are considered in the total amount evaluation of CO2 released. The results show that with current technologies for battery manufacturing, and a significant proportion of national grid electricity delivered by fossil fuels, BEV is the best choice to reduce carbon emissions for shorter driving ranges. In the case of electricity generation mainly by low-carbon sources, FCEV and BEV-FCEV hybrid vehicles end up with lower carbon dioxide emissions. In contrast, with electricity mainly generated from fossil fuels, electric vehicles do not reduce CO2 emissions compared to combustion cars. [ABSTRACT FROM AUTHOR]

The integration of renewable energy sources (RES) has several complex technical and economic aspects, such as: grid reinforcement, tertiary power reserves required for intermittent operation of RES, promoting or support scheme, etc. In this paper, the focus will be given to wind and photovoltaic energy integration from the promoting scheme point of view, with a special emphasis on the case of Romania. In this respect, we propose a model that shows the relation between wind and photovoltaic energy integration and support scheme in Romania. Due to the green certificates (GC) support scheme design that is related to several elements such as total consumption forecast, installed power of the plants based on each type of RES and their full load hours that are expected to vary, we also perform several sensitivity analyses. The GC support scheme implemented in Romania provides interesting insights regarding the installed power based on the primary energy source that could benefit from the GC for RES investors, policy and decision makers. [ABSTRACT FROM AUTHOR]

Green consumption is usually understood in the context of green consumption values and receptivity to green communication. Voluntary simplicity, a related yet distinct construct that relies on ecological responsibility, has not been included in the same framework. This paper bridges this gap and extends the original model to consider green consumption and voluntary simplicity in a unified structure. Based on a study conducted in Romania, it was found that 70% of the variation in buying behavior is explained by a combination of direct and mediated influences. The main takeaway is that any serious attempt to encourage responsible buying has to rely on a reduction in the absolute level of consumer demand. This result has far-reaching implications because the current paradigm of economic growth and prosperity is tributary to consumerism. The question is not how to avoid curtailing consumption and substitute green products for those harming the environment, but rather how to make voluntary frugality palatable. [ABSTRACT FROM AUTHOR]

This paper is an initial exploratory study that provides recommendations for the sustainable development of future automated and connected transport (ACT) systems in Romania. To achieve this, our paper investigates the different factors that influence mobility behaviour related to ACT systems through two different themes. The first part analyses (i) the strategic framework that is relevant to future ACT deployment and (ii) the spatial development patterns of large cities in Romania that might influence future mobility behaviour based on ACT systems. We presumed, and the study confirmed, that there is currently a poor focus on ACT systems in strategic documents and that the current spatial patterns show some premises for unsustainable mobility behaviour based on ACT systems. The second part describes the results of our analysis on the WISE-ACT survey deployed in Romania. We explored how informed Romanian citizens are about AVs; whether they are ready to use them; and what perceptions, concerns, and attitudes might influence their mobility behaviour when using ACT systems. The present analysis mainly shows that the perceptions of Romanian citizens are widely similar to those of citizens from other countries and that, for Romania, the orientation towards unsustainable forms of individual travel is maintained in terms of the future use of AVs. The recommendations that are presented here primarily address the spatial and attitudinal factors that have been identified as prerequisites for unsustainable future mobility behaviour linked to ACT systems. [ABSTRACT FROM AUTHOR]

The paper's main objective is to demonstrate the trading and flexibility of services amongst TSOs, DSOs, and Prosumers in a transparent, secure, and cost-effective manner using Blockchain-based TSO-DSO flexibility marketplace (EFLEX). The aim is to look for ways to help DSOs/TSOs be more flexible and more directly engaged in managing energy flows on the network. EFLEX will streamline the needs of both TSO and DSO on the same platform. Based on the paper's proposed services, the pilot service demonstration will be carried out in Bulgaria and Romania, and the main focus will be on congestion management, TSO-DSO Coordination, and Marketplace. The proposed objective is achieved by using Blockchain-based smart contracts and distributed ledger technology. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to emphasize the effects of knowledge management strategies toward organizational change in Romanian companies from the energy sector. This study explored a new vision to implement these types of organizational changes successfully in companies from the Romanian sector of energy and obtain their early benefits by using knowledge management strategies and also reveal the mediating effect of organizational learning and readiness for change. The results highlighted how energy companies can implement an Enterprise Resource Planning (ERP)-based change effectively through KM strategies. The results are equally valuable for all Romanian organizations that are currently changing their working environment. [ABSTRACT FROM AUTHOR]

This paper analyzes the impact of policy changes on the Romanian renewable energy producers. Attracted by a generous subsidy scheme, foreign and domestic investors flocked to the market. Consequently, the sector witnessed remarkable progress, especially in the wind power category. Romania fast approached the national target set by the European Union concerning the share of the country's energy consumption from renewable sources. However, frequent changes in the support scheme and in the regulations issued by public authorities led to chaos. The aim of the paper was to emphasize the evolution of renewable energy policy in Romania, to investigate the incentives and their effects, and to critically assess the impact of the changes on renewable energy producers. It highlights, by means of an exploratory study and several interviews with executives of renewable energy companies, the challenges and shortcomings of policymaking. The main finding was that the revision of the subsidy scheme and the changes in energy policy that followed are the major determinants for the declining financial performance of renewable energy producers. Subsequently, some recommendations for improved policymaking are suggested, so as to re-establish the trust of investors and to promote the sustainable development of the sector. [ABSTRACT FROM AUTHOR]

Power exchanges in Europe have been operating since the 1990s, while in the region of Southeast Europe (SEE) they are only a few years old. Volatility is considered to be one of the indicators that define the level of market development. In this paper, the authors examine 15 power markets in Europe with the novelty of special attention dedicated to the SEE markets, in terms of their volatility. The aim of this paper is to investigate volatility on SEE markets, and their correlation with developed European markets. Power price volatility is measured by price velocity concepts, the daily velocity based on daily/monthly/quarterly/yearly and overall average power prices. The outcomes reveal that power price volatility is higher in new SEE markets than in more mature European markets. The least volatile market is the Greek pool, followed by Switzerland and Austria. The Bulgarian market is the most volatile, followed by that of Romania, and these markets are nearly twice as volatile as the ones previously mentioned. A correlation matrix is carried out and confirms positive correlation between all markets in terms of their average prices. However, a correlation matrix of measured volatilities depicts a negative correlation, in some cases, between SEE and Central European (CE) markets. [ABSTRACT FROM AUTHOR]

Based on the national level data on energy consumption by final consumption sectors (agricultural, industrial, construction, residential and transport), the present study is aimed at estimating the energy consumption at county level. The overall energy Romania has consumed throughout a year has been broken down into 'demographic' and 'economic' components. The changes in the two components were determined on an annual basis for the following reference years: 1995, 2000, 2005, 2010 and 2015. The variables used in the current investigation were assembled into two groups of indicators: demographic (urban population, population size, proportion of the population aged 65 years and over, the economically active population divided according to activities of national economy: agriculture, industry, transport), and economic (GDP per capita, energy consumption by the activities of the national economy: agriculture, residential, industry, transport). In some cases, where a significant share of the population worked in the industry sector (with the probability of a diversified industry), our calculations overestimated energy consumption. This may also be due to the cumulative effect of some demographic factors (i.e., the high degree of urbanization). The paper discusses the effect of the demographic variables (e.g., size, age and occupational structures) have on energy consumption. The paper shows that the economic growth Romania has been subject to since the year 2000 has led to a rise in energy consumption for two economic activities (agriculture, transportation) and it also turned out that improving the technologies used in industry has a positive effect on energy efficiency. Energy efficiency depends, in addition to the technologies used in each economic activity, on demographic factors. Some of the demographic factors have different trends in terms of energy consumption. The effect of the population size must be explained in the context of changes in the structure by age groups (aging of the population), changes in fertility and mortality rates. Moreover, the economic structure changes alongside the alterations undergone by the demographic structure. This, in turn, changes production and consumption, transport infrastructure, as well as social services. In order to draw firm conclusions about the relationship between energy consumption and population structure by age group, further detailed studies are needed, including making use of other indicators. [ABSTRACT FROM AUTHOR]

E-waste and end-of-life vehicles (ELVs) are fast-growing waste streams in the EU and beyond that require specific collection and treatment activities to avoid environmental pollution and resource depletion fed by the linear economy model. This paper aims to investigate the links between e-waste and ELVs streams and the circular economy approach of the EU. Romania is examined as a relevant case study for the central and eastern European Region regarding: (i) the current e-waste and ELVs management deficiencies and challenges in line with circular economy principles promoted by EU; (ii) analysis of E-waste and ELVs flows data; and (iii) best circular economy initiatives related to e-waste and ELVs in Romania, including the opportunity to create new jobs in treatment activities that the simple operations from the first stages of e-waste recycling can produce locally and regionally in Romania. This work points out the current knowledge gaps and future research directions for these special waste streams in Romania and beyond. [ABSTRACT FROM AUTHOR]

Solar resource forecasting is an essential step towards smart management of power grids. This study aims to increase the performance of intra-hour forecasts. For this, a novel ensemble model, combining statistical extrapolation of time-series measurements with models based on machine learning and all-sky imagery, is proposed. This study is conducted with high-quality data and high-resolution sky images recorded on the Solar Platform of the West University of Timisoara, Romania. Atmospheric factors that contribute to improving or reducing the quality of forecasts are discussed. Generally, the statistical models gain a small skill score across all forecast horizons (5 to 30 min). The machine-learning-based methods perform best at smaller forecast horizons (less than 15 min), while the all-sky-imagery-based model performs best at larger forecast horizons. Overall, for forecast horizons between 10 and 30 min, the weighted forecast ensemble with frozen coefficients achieves a skill score between 15 and 20%. [ABSTRACT FROM AUTHOR]

Renewable energy represents a crucial resource in the efforts to combat climate change and reduce dependence on fossil fuels. In the past few decades, Romania has lessened its environmental footprint and played an important role in actions against climate change. In this research, the energy sector in Romania is analyzed from a holistic perspective as a complex adaptive system by using econometric tools. The purpose of the research is to analyze the Romanian energy sector as a cybernetic system and to study the long-run and the short-run causal impact of greenhouse gas emissions (GHG) and renewable energy (RE) on real GDP per capita. The causality among GHG, foreign direct investment (FDI), RE, and real GDP is checked by means of the autoregressive distributed lag model (ARDL). The time series are extracted from Eurostat and OECD databases and cover the period 2000-2021. The results reveal that (i) the variables are cointegrated according to the ARDL bounds test; (ii) in the long run, GHG negatively impacts GDP, RE positively impacts GDP; (iii) in the short run, GHG and RE positively impact GDP; (iv) the speed of adjustment is around 32%. The study holds significance both for scholars and the policy makers from the governmental environment agencies that should decide how to effectively reduce GHG emissions, promote renewable energy adoption, and design policies to facilitate the transition to a low-carbon economy. [ABSTRACT FROM AUTHOR]

The rapid development of innovations in the industry 4.0 era led to new or evolved companies. At the same time, the accepted concept of carbon-free development requires building a new philosophy for the company's management. The paper aims to analyse the key attributes of teal organisations (as a new type of a company) from the energy sector (as a core sector for carbon-free transformation). The paper summarises the core features of teal organisations and their attributes. In the paper, three hypotheses are tested: innovations and technologies are the most used attributes among teal organisations from the energy sector; organisational and corporate culture are the least used attributes among teal organisations from the energy sector; in the energy sector, the companies that have the attributes of teal organisations primarily work in countries with a high level of innovation and information technologies (as a core indicator of Industry 4.0) and economic development. For testing the hypotheses, the following methods are applied: a Friedman test, a paired-samples t-test, the principal components analysis, a correlation analysis, an ANOVA test (analysis of variance), and a regression analysis. The online survey generates the data for analysis. The object of the research is the workers from the energy sector companies from five countries (Poland, Ukraine, Georgia, Slovakia, and Romania). The findings of the statistical analysis confirm the first and second hypotheses. Companies in the energy sector mostly use innovations and technologies as the attributes of teal organisations. The regression analysis results show that an increase of 1% of patent applications leads to an increased energy efficiency of 1.29%. Additionally, the implemented features of teal organisations in the energy sector allow for improving the country's energy efficiency, which, as a consequence, then boosts carbon-free development. [ABSTRACT FROM AUTHOR]

Concern about energy in the European Union (EU) has been a recurrent issue from the very beginning. Though initially addressed at the state level, energy is now a shared competency as stressed by article 194 of the Treaty on the Functioning of the European Union. New challenges, added from time to time, need public support in order to be properly addressed. Such is the case of substituting traditional energy production with renewable energy sources. Our paper seeks to determine whether the Romanian public opinion favors such an evolution, which is traditionally associated with significant investment efforts. The study is focused on the north-east development region, which has the highest population and registered the fastest economic growth in 2019. The topic was explored through a survey applied to a sample of 649 household respondents. The results suggest strong support for introducing renewable energy sources, serious concerns about climate change, and a preoccupation for energy saving. Concerns regarding climate change or various economic factors, behaviors oriented towards reducing energy waste, as well as perceived knowledge on the matter are the factors with the biggest impact on supporting electricity production based on renewable energy sources. However, TV and online exposure have a negative impact on support. Demographics, along with social and political values remain mostly not significant. [ABSTRACT FROM AUTHOR]

Boosting the externalities across the water, energy, food, and waste (WEFW) sectors is challenging, especially considering tightening constraints such as population growth, climate change, resource-intensive lifestyles, increased waste production, sanitary crises and many others. The nexus approach supports the transition to a more sustainable future because intersectoral trade-offs can be reduced and externalities exploited, making imperative for decision makers, entrepreneurs, and civil society to simultaneously engage, with respect to all the components of the nexus. This research addressed intersectoral synergies and trade-offs in the case of the WEFW nexus in Romania, judging from the perspectives of entrepreneurial activity and economic results. The objective of this research was to explore the nexus in-depth by statistically analyzing the financial and economic indicators reported by active enterprises at county-level, based on the Romanian Ministry of Public Finance data. Research results describe the effects of the policies implemented in the fields of WEFW sectors. At the same time, attention was paid to the quality of the entrepreneurial activity, analyzed from the perspective of economic performance. This paper fills a research gap regarding the WEFW nexus by resorting to an economic and entrepreneurial performance assessment in order to find sectoral pathways toward policy cohesion in Romania. Findings suggested the existence of major trade-offs among sectors, owing to the fact that each county has a different development degree. [ABSTRACT FROM AUTHOR]

The energy sector is essential to a country's economy and social life. In recent years, the energy market in Romania has experienced a certain dynamism, influenced by multiple factors such as regional conflicts, national and EU energy legislation, liberalization of the energy market, and increasing demand for energy products. These factors determined a sharp increase in electricity, gas, and oil prices in Romania in recent years. Based on the above, the present study aims to analyze Romanian energy companies' financial performances and determine whether there is any correlation between their governance and their performance. In order to fulfill the research objectives, financial performance data were extracted and analyzed for a number of 43 energy companies in Romania, considering the financial statements prepared up to 31 December 2021. Using the scoring method, governance indices were determined for each company. Finally, using a linear regression model, we analyzed the correlation between governance and performance of the 43 companies. The results of the study indicate that there is a direct correlation of moderate intensity between the two variables, with the performance of energy companies being higher if they have implemented a governance system. [ABSTRACT FROM AUTHOR]

Models based on Numerical Weather Prediction (NWP) are widely used for the day-ahead forecast of solar resources. This study is focused on the calibration of the hourly global solar irradiation forecasts provided by the Global Forecast System (GFS), a model from the NWP class. Since the evaluation of GFS raw forecasts sometimes shows a high degree of uncertainty (the relative error exceeding 100%), a procedure for reducing the errors is needed as a prerequisite for engineering applications. In this study, a deep analysis of the error sources in relation to the state of the atmosphere is reported. Of special note is the use of sky imagery in the identification process. Generally, it has been found that the largest errors are determined by the underestimation of cloud coverage. For calibration, a new ensemble forecast is proposed. It combines two machine learning approaches, Support Vector Regression and Multi-Layer Perceptron. In contrast to a typical calibration, the objective function is constructed based on the absolute error instead of the traditional root mean squared error. In terms of normalized root mean squared error, the calibration roughly reduces the uncertainty in hourly global solar irradiation by 16%. The study was conducted with high-quality ground-measured data from the Solar Platform of the West University of Timisoara, Romania. To ensure high accessibility, all the parameters required to run the proposed calibration procedures are provided. [ABSTRACT FROM AUTHOR]

The COVID-19 pandemic obliged the Romanian government to take drastic measures to contain the virus. More than this, they imposed the heaviest restrictions in the EU. For more than a month, during the lockdown period, everything stopped: schools and universities had only online classes, national and international flights and gatherings were forbidden, and many restrictions for travel were imposed. This paper analyzes the changes that occurred in electricity consumption linked with economic growth, during the pandemic, in Romania. For a better understanding of the correlations between gross domestic product (GDP) and electricity consumption (EC) in different economic contexts, the period 2008–2020 was divided into three series: the 2008–2012 financial crisis and the post-crisis recovery period, the 2013–2019 period of economic growth, and the Q1–Q3 2020 pandemic period. Using correlation coefficients and regression analysis, the authors found that the GDP decoupled from EC in the first period. The increase in GDP led to an increase in the consumption of electricity and the electricity produced from RESs in the second period. In Q3 2020, the real GDP is different from the calculated GDP, due to the pandemic. In Romania, the electricity consumption decreased within the first nine months of the pandemic due to the economic contraction. The electricity that comes from coal and hydropower plants suffered the biggest decrease. If the electricity that comes from NRESs can be adapted to the economic demands, the quantity of electricity that comes from RESs will be influenced by the climate conditions. [ABSTRACT FROM AUTHOR]

This paper analyzes the impact of the COVID-19 pandemic on economic growth and electricity consumption and investigates the hypothesis of the influence of this consumption on the gross domestic product (GDP) for Romania. Using time series on monthly electricity consumption and quarterly GDP and a multi-linear regression model, we performed an analysis of the evolution of these indicators for 2007–2020, a comparison between their behavior during the financial crisis vs. COVID-19 crisis, and empirically explore the relationships between GDP and electricity consumption or some of its components. The results of the analysis confirm that the shock of declining activity due to the COVID-19 pandemic had a severe negative impact on electric energy consumption and GDP in the first half of 2020, followed by a slight recovery. By using a linear regression model, long-term relationships between GDP and domestic and non-household electricity consumptions were found. The empirically estimated elasticity coefficients confirm the more important impact of non-household electricity consumption on GDP compared to the one of domestic electricity consumption. In the context of the COVID-19 pandemic, the results of the study could be useful for optimizing energy and economic growth policies at the national and European levels. [ABSTRACT FROM AUTHOR]

Considering the necessity of achieving economic development by keeping the quality of the environment, the aim of this paper is to study the impact of economic growth on GHG emissions in a sample of Central and Eastern European (CEE) countries (V4 countries, Bulgaria and Romania) in the period of 1996–2019. In the context of dynamic ARDL panel and environmental Kuznets curve (EKC), the relationship between GHG and GDP is N-shaped. A U-shaped relationship was obtained in the renewable Kuznets curve (RKC). Energy consumption, domestic credit to the private sector, and labor productivity contribute to pollution, while renewable energy consumption reduces the GHG emissions. However, more efforts are required for promoting renewable energy in the analyzed countries. [ABSTRACT FROM AUTHOR]

This paper presents the use of a three-phase four-wire shunt active power filter to improve the power quality in the Department of Industrial Electronics of a large enterprise from Romania. The specificity is given by the predominant existence of single-phase consumers (such as personal computers, printers, lighting and AC equipment). In order to identify the power quality indicators and ways to improve them, an A-class analyzer was used to record the electrical quantities and energy parameters in the point of common coupling (PCC) with the nonlinear loads for 27 h. The analysis shows that, in order to improve the power quality in PCC, three goals must be achieved: the compensation of the distortion power, the compensation of the reactive power and the compensation of the load unbalance. By using the conceived three-leg shunt active power filter, controlled through the indirect current control method in an original variant, the power quality at the supply side is very much improved. In the proposed control algorithm, the prescribed active current is obtained as a sum of the loss current provided by the DC voltage and the equivalent active current of the unbalanced load. The performance associated with each objective of the compensation is presented and analyzed. The results show that all the power quality indicators meet the specific standards and regulations and prove the validity of the proposed solution. [ABSTRACT FROM AUTHOR]

One method to reduce CO2 emissions from vehicle exhaust is the use of liquified petroleum gas (LPG) fuel. The global use of this fuel is high in European countries such as Poland, Romania, and Italy. There are a small number of computational models for the purpose of estimating the emissions of LPG vehicles. This work is one of the first to present a methodology for developing microscale CO2 emission models for LPG vehicles. The developed model is based on data from road tests using the portable emission measurement system (PEMS) and on-board diagnostic (OBDII) interface. This model was created from a previous exploratory data analysis while using gradient-boosting machine learning methods. Vehicle velocity and engine RPM were chosen as the explanatory variables for CO2 prediction. The validation of the model indicates its good precision, while its use is possible for the analysis of continuous CO2 emissions and the creation of emission maps for environmental analyses in urban areas. The validation coefficients for the selected gradient-boosting method of modelling CO2 emissions for an LPG vehicle are the R2 test of 0.61 and the MSE test of 0.77. [ABSTRACT FROM AUTHOR]

This paper investigates the potential of Romanian renewable energy across energy production and consumption definitions. Moreover, it presents a model that estimates the regional evolution of renewable energy diffusion, focusing primarily on hydro energy. Statistics showed that Romanian consumers have a key role in developing the renewable energy market, while it is also very important to ensure the ability of renewable energy suppliers to accommodate this demand. Sample data and econometric analysis were applied to delineate factors influencing Romanian consumers' awareness about renewable energy. The findings highlighted a strong connection between those who bear the cost of renewable energy development and the actual beneficiaries of a clean environment; in that sense, they identify the major drivers and barriers for renewable energy diffusion in Romania. The results of this research could be used for further research in the area of implementing renewable energy projects in the region. [ABSTRACT FROM AUTHOR]

The energy crisis caused first by the COVID-19 pandemic and continued by the Russo-Ukrainian War has demonstrated that energy is a determining factor in the conduct of activities of any state. Several studies have examined the relationship between energy consumption and economic growth, developing various theories, but there is no consensus. This study investigates relationships by analyzing several regression models and choosing the fittest. Then, the verification of its validity is performed through the neural network, which gives greater credibility to the results obtained. Furthermore, using a structural analysis, the investigation is expanded to ranking the impact of sector-specific energy consumption on economic growth. The research includes data from 1995 to 2020 for the European Union (EU) and Romania. The results indicate that short-term energy consumption can have a positive or negative impact on economic growth, both in the EU and Romania. The structural analysis highlights the direct and indirect effects, with different intensities, of sector-specific energy consumption on economic growth. This study is interested primarily in the conditions of uncertainty caused by the COVID-19 pandemic and the Russo-Ukrainian War, to enable the EU and each member state to take effective energy policy measures to ensure their energy security. [ABSTRACT FROM AUTHOR]

This research aims to identify the influence of fiscal policy, financial development and economic growth on the increase of renewable consumption in Romania. To achieve our objective, we employ bivariate regressions through the Autoregressive Distributed Lag method, over the 2000–2020 period, to examine these influences. We find clear evidence that the variables observed (implicit tax rate on energy, external debt stocks, real GDP per capita, environmental tax revenues from energy taxes, and market capitalisation of listed domestic companies) have significant effects on the use of renewable energy. Four unidirectional causal relationships were identified in the long run: two from independent variables towards the dependent variable and two from the dependent variables towards two other independent variables. The importance of this study is that its results can contribute to the finding of the most suitable solutions to improve renewable energy consumption in Romania and mitigate the impact of climate change. Consequently, the results of this study reveal significant conclusions and policy recommendations for Romania moving towards sustainable and green economic growth, through a balanced set of policies and measures smartly applied, accompanied by a solid rate of absorption of green funds. [ABSTRACT FROM AUTHOR]

Energy losses and bus voltage levels are key parameters in the operation of electricity distribution networks (EDN), in traditional operating conditions or in modern microgrids with renewable and distributed generation sources. Smart grids are set to bring hardware and software tools to improve the operation of electrical networks, using state-of the art demand management at home or system level and advanced network reconfiguration tools. However, for economic reasons, many network operators will still have to resort to low-cost management solutions, such as bus reactive power compensation using optimally placed capacitor banks. This paper approaches the problem of power and energy loss minimization by optimal allocation of capacitor banks (CB) in medium voltage (MV) EDN buses. A comparison is made between five metaheuristic algorithms used for this purpose: the well-established Genetic Algorithm (GA); Particle Swarm Optimization (PSO); and three newer metaheuristics, the Bat Optimization Algorithm (BOA), the Whale Optimization Algorithm (WOA) and the Sperm-Whale Algorithm (SWA). The algorithms are tested on the IEEE 33-bus system and on a real 215-bus EDN from Romania. The newest SWA algorithm gives the best results, for both test systems. [ABSTRACT FROM AUTHOR]

In this paper, an improved smart meter data-based three-stage algorithm to calculate the power/energy losses in three-phase networks with the voltage level below 0.4 kV (low voltage—LV) is presented. In the first stage, the input data regarding the hourly active and reactive powers of the consumers and producers are introduced. The powers are loaded from the database of the smart metering system (SMS) for the consumers and producers integrated in this system or files containing the characteristic load profiles established by the Distribution Network Operator for the consumers, which have installed the conventional meters non-integrated in the SMS. In the second stage, a function, which is based on the work with the structure vectors, was implemented to easily identify the configuration of analysed networks. In the third stage, an improved version of a forward/backward sweep-based algorithm was proposed to quickly calculate the power/energy losses to three-phase LV distribution networks in a balanced and unbalanced regime. A real LV rural distribution network from a pilot zone belonging to a Distribution Network Operator from Romania was used to confirm the accuracy of the proposed algorithm. The comparison with the results obtained using the DigSilent PowerFactory Simulation Package certified the performance of the algorithm, with the mean absolute percentage error (MAPE) being 0.94%. [ABSTRACT FROM AUTHOR]

The primary objective of this research was to determine the impact of renewable energy, alternative and nuclear energy, urbanization, energy use, and fossil fuel energy consumption on Romanian economic development. To investigate the relation between variables, we employed the Autoregressive Distributed Lag (ARDL) technique in conjunction with FMOLS (Fully Modified Least Squares) and CCR (Canonical Cointegrating Regression). Long-run and short-run findings suggest that alternative and nuclear energy, as well as fossil fuel consumption, has a positive association with economic growth, but renewable energy, urbanization, and energy usage have an adversative relationship with economic growth. Similarly, FMOLS and CCR statistics indicate that alternative and nuclear energy and fossil fuel consumption have a favorable impact on economic development. Renewable energy consumption, urbanization, and energy use, on the other hand, revealed a negative connection with economic progress. Conservative solutions are necessary to implement appropriate policies to address energy consumption concerns in Romania in order to improve economic development. [ABSTRACT FROM AUTHOR]

Taking into account the international policies in the field of environmental protection in the world in general, and in the European Union in particular, the reduction of greenhouse gas (GHG) emissions, and primarily of carbon dioxide, has become one of the most important objectives. This can be obtained through various renewable energy sources and non-polluting technologies, such as the mixing of hydrogen and natural gas. Combining hydrogen with natural gas is an emerging trend in the energy industry and represents one of the most important changes in the efforts to achieve extensive decarbonisation. The importance of this article consists of carrying out a techno-economic study based on the simulation of annual consumptions regarding the construction and use of production capacities for hydrogen to be used in mixtures with natural gas in various percentages in the distribution network of an important operator in Romania. In order to obtain relevant results, natural gas was treated as a mixture of real gases with a known composition as defined in the chromatographic bulletin. The survey presents a case study for the injection of 5%, 10%, and 20% hydrogen in the natural gas distribution system of Bucharest, the largest city in Romania. In addition to conducting this techno-economic study, the implications for final consumers of this technical solution in reducing greenhouse gas emissions—mainly those of carbon dioxide from combustion—are also presented. [ABSTRACT FROM AUTHOR]

Under the European Union (EU) energy efficiency targets that Romania has assumed, increasing the share of solar energy has been one of the main points to be considered. The most important solar energy resources are found in the lowlands and low hills in southern and south-eastern parts of the country. The current paper is focused on the Romanian Plain, which has the best environmental conditions to support the development of photovoltaic (PV) farms. One hundred and ten PV farms have been identified and mapped which cover a total area of 1393 hectares. Although it provides a clean and sustainable energy source, the related environmental implications of PV farms could be either positive or negative. In this study, some of the main categories of impacts have been selected for identification and analysis of their environmental consequences. Several indicators have been computed: the share of PV farms from the main land use/cover categories and main soil types, and the distance of PV farms to forests, water bodies, or protected areas. The overall results of the study reveal the current and potential impacts of PV farms in order to understand the interactions between the environment and the use of renewable energy sources and further support science-based solutions for sustainable development. [ABSTRACT FROM AUTHOR]

Due to the population's growing need for energy and the increasing impact of the phenomena of global warming and climate change on a global level, it becomes imperative to diminish energy consumption worldwide. For this reason, a deeper understanding of factors that encourage energy-saving habits and overall lifestyle is required. This research examined the factors that hold an impact on the adoption of energy-saving habits in Romania. It used eight constructs that were checked to see if they influence the individuals' intentions to save energy. The research used a quantitative analysis approach, with primary data assembled through a survey of the population from six developed counties in Romania. In order to investigate and assess the data, structural equation modeling (SEM) was used. The results show that environmental awareness, perceived consumer effectiveness and a collectivistic perspective affect individuals in implementing energy-saving habits (in their life) in a significant and positive way. However, resistance to change and perceived costs were identified as having a negative and significant impact on the individuals' implementation of such habits within their households. The outcomes of this research play a part in raising awareness of what could determine a more energy-saving lifestyle, and therefore it is essential that stakeholders within the energy sector in Romania consider the aspects of environmental awareness, perception of consumer effectiveness, perceived costs, collectivism and resistance to change during the development of programs of energy efficiency. [ABSTRACT FROM AUTHOR]

Romania introduced in 2018 an amendment to the national law 220/2008 by including the Prosumer concept that allows investors in grid-connected photovoltaic systems with a capacity up to 27 kWp to receive a feed in tariff for the electricity delivered to the grid representing approximatively one third of the price paid when the electricity is consumed from the grid. Thus, the challenge is to use as much as possible the photovoltaic power when it is produced. A methodology is developed to evaluate how much of the electrical energy output of a grid-connected photovoltaic platform is used by a geothermal heat pump for space heating in a building. A numerical simulation is performed in Trnsys17 based on locally measured meteorological parameters over a period of one entire year. A case study is presented for which the characteristics of the building, of the heat pump system and of the photovoltaic system are described and integrated into the transient simulation environment. The numerical results are comparatively presented and discussed along with experimental data for sunny days in cold season. For the analysed case study, the self-consumption is 16%, significantly lower than the yearly coverage degree of 70%. Further research can be done to increase the self-consumption. [ABSTRACT FROM AUTHOR]

Consumer behaviour in the energy field is playing a more important role in the new approach dominated by the proliferation of renewable energy sources. In this new context, the grid has to balance the intermittent and uncertain renewable energy generated, and find solutions, also, on the consumer side for increasing the stability and reliability of the energy system. The main de-mand response solutions are price and incentive based, but there is a need to identify the main factors which can influence their efficiency due to the fact that there is a lack of knowledge about the preferences of consumers. The main goal of this article is to identify the main demand response solutions and the related key factors which influence the participation of consumers in demand response programs and may contribute to the spread of renewable energy sources. For this research, semi-structured interviews were organised with experts in energy from Romania, Hungary and Serbia, as well as workshops with experts in energy, and an online survey with customers for electricity. This article reduces the gap between the results of technical studies, related in demand response programs, and their practical implementations, where the consumer behaviour and its social dimensions are neglected even though, in reality, they are playing the main role. The results suggest that the consumer's participation in demand response programs is highly influenced by different aspects related to the promotion of the renewable energy and the reduction of CO2 emissions and the global warming impact. [ABSTRACT FROM AUTHOR]

CoME EASY is a European Union H2020 project started in May 2018, which aims to help local public authorities secure a more sustainable energy and climate policy, in line with the New Green Deal and Fit for 55 initiatives. The main idea of CoME EASY is to offer an integrated package of on-line tools that synchronize European Energy Awards (EEA) with Covenant of Mayors (CoM), ISOs, Smart Cities, and other initiatives that allow local communities to have multiple commitments for energy efficiency and climate with less effort. EEA is a quality management and awarding system for municipalities and regions, which started in 1988 in Switzerland and now includes more than 1700 municipalities from 8 countries and 10 new pilot countries with more than 65 million people belonging to the local communities that are involved. There are six main areas of activity in EEA (Development and Spatial Planning Strategy, Municipal Buildings and Facilities, Supply and Disposal, Mobility, Internal Organization, Communication and Cooperation) through which municipalities are driven by advisors so as to receive a score in percentage for each area, which further allows them to compare with other communities. Romania has been an EEA pilot country since 2016 and, despite initial problems in implementing the system, now has three communities, Iași (Romania second largest city), Alba Iulia (the so-called other Romanian capital), and Vama Buzăului, included in CoME EASY. These cities tested frameworking tools and managed to be assessed with EAA tools, and developed a Sustainable Energy and Climate Action Plan synchronously. Owing to the CoME EASY tools, all of these communities were able to deliver key performance indicators that are in line with the United Nations Sustainable Development Goals. [ABSTRACT FROM AUTHOR]

Demand response plays a very important role in balancing the intermittent production of an increasing share of renewable energy sources on the energy market. This article analyses the importance of demand response and the role of aggregators for the new development of the electricity market, where the renewables will play a more important role. The main objective of this research is to determine the acceptance level of demand response and its implementation on the energy consumer side. This acceptance should include a professional actor, the aggregator which is assuming the role of optimizing the relation between energy producers and consumers, and to monitor the implementation and use of demand response. The research is based on semi-structured interviews with experts in energy from Hungary, Romania and Serbia, on workshops with experts and a wider online survey with end customers for electricity. The results indicate that there is a willingness potential to implement demand response programs with aggregators as intermediaries between energy providers and end consumers of electrical energy. [ABSTRACT FROM AUTHOR]

The process of reaching carbon neutrality by 2050 and cutting CO2 emissions by 2030 by 55% compared to 1990 as per the EU Green Deal is highly complex. The energy mix must be changed to ensure long-term environmental sustainability, mainly by closing down coal sites, while preserving the energy-intensive short-term economic growth, ensuring social equity, and opening opportunities for regions diminishing in population and potential. Romania is currently in the position of deciding the optimal way forward in this challenging societal shift while morphing to evidence-based policy-making and anticipatory governance, mainly in its two coal-mining regions. This article provides possible future scenarios for tackling this complex issue in Romania through a three-pronged, staggered, methodology: (1) clustering Romania with other similar countries from the point of view of the Just Transition efforts (i.e., the energy mix and the socio-economic parameters), (2) analyzing Romania's potential evolution of the energy mix from the point of the thermal efficiency of two major power plants (CEH and CEO) and the systemic energy losses, and (3) providing insights on the socio-economic context (economic development and labor market transformations, including the component on the effects on vulnerable consumers) of the central coal regions in Romania. [ABSTRACT FROM AUTHOR]

About ten hydroelectric power plants realized from 1970 to 1990 in Romania are confronted with stator overheating. The developed mathematical model analyzes the voltage stability based on modal analysis of the Jacobian matrix, identifying the hazardous modes of variation between voltage and flow rate, correlated with the characteristics of the analyzed generators and their response to these variations. Vulnerable elements in the system for inductive and capacitive modes of operation are identified. In these conditions, hydro generators cannot attend the secondary voltage control, not even for a frequency power dependency control. The elaborated mathematical model was tested at the hydroelectric power plants Gilceag, Mariselu, and Susag with similar functioning conditions. The necessary conditions for stator ventilation and variation of flow hydrodynamic parameters during the operation were established. The theoretical model was tested with an experimental method applied separately for the thermal and ventilation conditions. Some results obtained during the measurements are illustrated and correlated with the theoretical results. The model was tested to prevent the onset instability of voltage drops and accelerated overheating. Finally, some solutions to minimize the stators overheating based on local conditions are recommended. [ABSTRACT FROM AUTHOR]

The ongoing digitization of the economy has led to the creation and functioning of platform model socio-economic systems. It is also reflected in the changes in patterns of energy consumption in households. In the first cross-section, it is an industrial revolution, with environmental benefits. However, platforms are primarily a revolution in the consumption sphere, and here, the effects of digitization are not fully recognized. Our social needs are increasingly met "through accessibility" without us leaving our home. Due to the home's multifunctionality, based on the availability of platform services, household energy consumption should be viewed differently today than before. The article aims to show the changes in Central and Eastern Europe (CEE) household energy consumption between 2008–2018 and their assessment through the prism of the economy's platformization methods. The study presents the changes in energy consumption in households and determines the correlations between platformization (the author's index) and changes in energy consumption in households with the use of taxonomic methods. The platformization leaders—Estonia and Lithuania—were subjected to a more detailed analysis. The presented method(s) may be useful in predicting the changes in households' energy consumption caused by the digitization of other countries in the region (countries under transformation and outsiders-Bulgaria, Romania), in implementing household energy management systems, and in a better adjustment of regulations directed at these consumers. [ABSTRACT FROM AUTHOR]