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The global photovoltaic (PV) installed capacity, vital for the electric sector's decarbonation, reached 1552.3 GW p in 2023. In France, the capacity stood at 19.9 GW p in April 2024. The growth of the PV installed capacity over a year was nearly 32% worldwide and 15.7% in France. However, integrating PV electricity into grids is hindered by poor knowledge of rooftop PV systems, constituting 20% of France's installed capacity, and the lack of measurements of the production stemming from these systems. This problem of lack of measurements of the rooftop PV power production is referred to as the lack of observability. Using ground-truth measurements of individual PV systems, available at an unprecedented temporal and spatial scale, we show that by estimating the PV power production of an individual rooftop system by combining solar irradiance and temperature data, the characteristics of the PV system inferred from remote sensing methods and an irradiation-to-electric power conversion model provides accurate estimations of the PV power production. We report an average estimation error (measured with the pRMSE) of 10% relative to the system size. Our study shows that we can improve rooftop PV observability, and thus its integration into the electric grid, using little information on these systems, a simple model of the PV system, and weather data. More broadly, this study shows that limited information is sufficient to derive a reasonably good estimation of the PV power production of small-scale systems. [ABSTRACT FROM AUTHOR]

This comprehensive study explores the influence of aerosols and clouds on solar radiation in the urban environments of nine of Greece's largest cities over the decade from 2014 to 2023. Utilizing a combination of Earth Observation data, radiative transfer models, and geographic information systems, the research undertook digital surface modeling and photovoltaic simulations. The study meticulously calculated the optimal rooftop areas for photovoltaic installation in these cities, contributing significantly to their energy adequacy and achieving a balance between daily electricity production and demand. Moreover, the research provides an in-depth analysis of energy and economic losses, while also highlighting the environmental benefits. These include a reduction in pollutant emissions and a decrease in the carbon footprint, aligning with the global shift towards local energy security and the transformation of urban areas into green, smart cities. The innovative methodology of this study, which leverages open access data, sets a strong foundation for future research in this field. It opens up possibilities for similar studies and has the potential to contribute to the creation of an updated, comprehensive solar potential map for continental Greece. This could be instrumental in climate change mitigation and adaptation strategies, thereby promoting sustainable urban development and environmental preservation. [ABSTRACT FROM AUTHOR]

To address environmental issues, Indonesia aims to achieve a 23% renewable energy share by 2025 and 31% by 2050, according to the National Energy Plan. This article examines the regulations governing the management of rooftop solar power plant (rooftop-PV) in Indonesia and their connection to pro-environment consumer behavior. Despite Indonesia's ambitious targets for Renewable Energy (RE) growth, progress in the field still needs improvement. Pro-environmental behavior (PEB) within the community is crucial for adopting rooftop PV as a more environmentally friendly energy alternative. This research employs a qualitative descriptive methodology with content analysis to evaluate the current situation. The research findings indicate that rooftop PV offers economic benefits through cost savings for consumers and is supported by existing regulations. However, some businesses feel that the government needs to expedite revising relevant regulations to address investment stagnation and installed solar panel capacity. Concerns arise that proposed policy changes may hinder the growth of rooftop PV businesses and the achievement of national capacity targets. The role of pro-environment consumer behavior, which has the potential to drive rooftop PV adoption, will be influenced by psychological and social factors, as well as changes in applicable regulations. [ABSTRACT FROM AUTHOR]

In the context of power system decarbonization, the demand-side strategy for increasing the share of renewable energy is studied for two constrained energy systems. This strategy, which is currently widely suggested in policies on the energy transition, would impact consumer behavior. Despite the importance of studying the latter, the focus here is on decisions regarding the type, location, and timeframe of implementing the related measures. As such, solutions must be assessed in terms of cost and feasibility, technological learning, and by considering geographical and environmental constraints. Based on techno-economic optimization, in this paper we analyze the evolution of the power system and elaborate plausible long-term trajectories in the energy systems of two European islands. The case studies, Procida in Italy and Hinnøya in Norway, are both electrically connected to the mainland by submarine cables and present issues in their power systems, which are here understood as relatively isolated power systems. Renewable energy integration is encouraged by legislative measures in Italy. Although not modeled here, they serve as a backbone for the assumptions of increasing these investments. For Procida, rooftop photovoltaics (PV) coupled with energy storage are integrated in the residential, public, and tertiary sectors. A price-based strategy is also applied reflecting the Italian electricity tariff structure. At a certain price difference between peak and off-peak, the electricity supply mix changes, favoring storage technologies and hence decreasing imports by up to 10% during peak times in the year 2050. In Norway, renewable energy resources are abundant. The analysis for Hinnøya showcases possible cross-sectoral flexibilities through electrification, leading to decarbonization. By fine-tuning electric vehicle charging tactics and leveraging Norway's electricity pricing model, excess electricity demand peaks can be averted. The conclusions of this double-prospective study provide a comparative analysis that presents the lessons learnt and makes replicability recommendations for other territories. [ABSTRACT FROM AUTHOR]

---With the increasing request for integrating rooftop photovoltaic (PV) systems into the distribution grid, it is crucial to prevent the potential negative impacts of high PV penetration. Considering the uncertainty and variability characteristics of high rooftop PV penetration, a stochastic approach for determining PV hosting capacity (HC)—the maximum capacity of a PV system to receive electricity from the power distribution network before the network reaches an operating limit violation—is necessary. Therefore, this study proposes calculating PV hosting capacity using the Monte Carlo simulation. Unlike previous works, this paper uses real feeders as case studies, representing both urban and rural areas. The feeder representing an urban area with many industrial and business customers has a higher hosting capacity, 31 % of full load, compared to the feeder representing rural areas, which has 18 % of full load. By using actual feeders that represent urban and rural areas, more representative results for specific problems can be achieved without assuming urban and rural feeders have the same specific problems.

To address environmental issues, Indonesia aims to achieve a 23% renewable energy share by 2025 and 31% by 2050, according to the National Energy Plan. This article examines the regulations governing the management of rooftop solar power plant (rooftop-PV) in Indonesia and their connection to pro-environment consumer behavior. Despite Indonesia’s ambitious targets for Renewable Energy (RE) growth, progress in the field still needs improvement. Pro-environmental behavior (PEB) within the community is crucial for adopting rooftop PV as a more environmentally friendly energy alternative. This research employs a qualitative descriptive methodology with content analysis to evaluate the current situation. The research findings indicate that rooftop PV offers economic benefits through cost savings for consumers and is supported by existing regulations. However, some businesses feel that the government needs to expedite revising relevant regulations to address investment stagnation and installed solar panel capacity. Concerns arise that proposed policy changes may hinder the growth of rooftop PV businesses and the achievement of national capacity targets. The role of pro-environment consumer behavior, which has the potential to drive rooftop PV adoption, will be influenced by psychological and social factors, as well as changes in applicable regulations.

The global photovoltaic (PV) installed capacity, vital for the electric sector’s decarbonation, reached 1552.3 GWp in 2023. In France, the capacity stood at 19.9 GWp in April 2024. The growth of the PV installed capacity over a year was nearly 32% worldwide and 15.7% in France. However, integrating PV electricity into grids is hindered by poor knowledge of rooftop PV systems, constituting 20% of France’s installed capacity, and the lack of measurements of the production stemming from these systems. This problem of lack of measurements of the rooftop PV power production is referred to as the lack of observability. Using ground-truth measurements of individual PV systems, available at an unprecedented temporal and spatial scale, we show that by estimating the PV power production of an individual rooftop system by combining solar irradiance and temperature data, the characteristics of the PV system inferred from remote sensing methods and an irradiation-to-electric power conversion model provides accurate estimations of the PV power production. We report an average estimation error (measured with the pRMSE) of 10% relative to the system size. Our study shows that we can improve rooftop PV observability, and thus its integration into the electric grid, using little information on these systems, a simple model of the PV system, and weather data. More broadly, this study shows that limited information is sufficient to derive a reasonably good estimation of the PV power production of small-scale systems.

This comprehensive study explores the influence of aerosols and clouds on solar radiation in the urban environments of nine of Greece’s largest cities over the decade from 2014 to 2023. Utilizing a combination of Earth Observation data, radiative transfer models, and geographic information systems, the research undertook digital surface modeling and photovoltaic simulations. The study meticulously calculated the optimal rooftop areas for photovoltaic installation in these cities, contributing significantly to their energy adequacy and achieving a balance between daily electricity production and demand. Moreover, the research provides an in-depth analysis of energy and economic losses, while also highlighting the environmental benefits. These include a reduction in pollutant emissions and a decrease in the carbon footprint, aligning with the global shift towards local energy security and the transformation of urban areas into green, smart cities. The innovative methodology of this study, which leverages open access data, sets a strong foundation for future research in this field. It opens up possibilities for similar studies and has the potential to contribute to the creation of an updated, comprehensive solar potential map for continental Greece. This could be instrumental in climate change mitigation and adaptation strategies, thereby promoting sustainable urban development and environmental preservation.

In the context of power system decarbonization, the demand-side strategy for increasing the share of renewable energy is studied for two constrained energy systems. This strategy, which is currently widely suggested in policies on the energy transition, would impact consumer behavior. Despite the importance of studying the latter, the focus here is on decisions regarding the type, location, and timeframe of implementing the related measures. As such, solutions must be assessed in terms of cost and feasibility, technological learning, and by considering geographical and environmental constraints. Based on techno-economic optimization, in this paper we analyze the evolution of the power system and elaborate plausible long-term trajectories in the energy systems of two European islands. The case studies, Procida in Italy and Hinnøya in Norway, are both electrically connected to the mainland by submarine cables and present issues in their power systems, which are here understood as relatively isolated power systems. Renewable energy integration is encouraged by legislative measures in Italy. Although not modeled here, they serve as a backbone for the assumptions of increasing these investments. For Procida, rooftop photovoltaics (PV) coupled with energy storage are integrated in the residential, public, and tertiary sectors. A price-based strategy is also applied reflecting the Italian electricity tariff structure. At a certain price difference between peak and off-peak, the electricity supply mix changes, favoring storage technologies and hence decreasing imports by up to 10% during peak times in the year 2050. In Norway, renewable energy resources are abundant. The analysis for Hinnøya showcases possible cross-sectoral flexibilities through electrification, leading to decarbonization. By fine-tuning electric vehicle charging tactics and leveraging Norway’s electricity pricing model, excess electricity demand peaks can be averted. The conclusions of this double-prospective study provide a comparative analysis that presents the lessons learnt and makes replicability recommendations for other territories.

This paper reports on modelling outcomes for improvements to building energy performance in Indonesia. Long-term climate effects due to building energy demand and carbon emissions are also considered. The global change assessment model (GCAM) was used to generate the related end-user building energy data, including socioeconomics, for urban areas of Indonesia. As a comprehensive study, the total life cycle of carbon in the building sector and the concept of zero-carbon buildings, including energy efficiency, zero-emissions electricity and fuel-switching options, were considered. Building shell conductance (U-value) of the building envelope, floor area ratio (FAR), air conditioner (AC) efficiency, electrical appliance (APL) efficiency, rooftop photovoltaic (PV) performance and ground source heat pump (GSHP) systems were considered as parameters to mitigate carbon emissions under the operational energy category in the GCAM. Carbon mitigation associated with the cement production process was considered in the raw material category. Urban population and labour productivity in Indonesia were used as base inputs with projected growth rates to 2050 determined from the available literature. Low growth rate 'LowRate' and high growth rate 'HighRate' were considered as variable inputs for U-value, FAR, AC efficiency, APLs efficiency and PV capacity factor to model emissions mitigation. The energy consumption of the GSHP was compared to the conventional reverse cycle ACs to identify the potential of the GSHP as a fuel-switching option. In the GCAM, the benchmark (base case scenario) data set was generated based on input parameters (urban population and labour productivity rate) only for the residential building sector in Indonesia. Total potential carbon emissions mitigation was found to be 432 Mt CO2-e for the residential building sector in Indonesia over 2020–2050. It was found that an average of 24% carbon emissions mitigation could be achieved by 2020–2030 and 76% by 2031–2050. [ABSTRACT FROM AUTHOR]

Rooftop photovoltaic (PV) systems are represented as projected technology to achieve net-zero energy building (NEZB). In this research, a novel energy structure based on rooftop PV with electric-hydrogen-thermal hybrid energy storage is analyzed and optimized to provide electricity and heating load of residential buildings. First, the mathematical model, constraints, objective function, and evaluation indicators are given. Then, the simulation is conducted under the stand-alone condition. The annual return on investment and the levelized cost of energy of the system are 36.37% and 0.1016 $/kWh, respectively. Residential building with the proposed system decreases annual carbon emission by 25.5 t. In the third part, simulation analysis under different grid-connected modes shows that building system will obtain better economics when connected to the grid, but the low-carbon performance will be reduced. Finally, the cumulative seasonal impact of the countywide rooftop PV buildings is discussed. The result indicates that the energy structure proposed in this paper can effectively reduce the grid-connected impact on the local grid. This model and optimization method developed in this paper is applicable to different climate zones and can provide management support to the investors of NZEB before the field test. [ABSTRACT FROM AUTHOR]

The European Union has set itself the goal of increasing its share in renewable energy up to 42.5% by 2030 by accelerating the clean energy transition plan. National legislation within the Member States must now adapt the strategic plans to rapidly implement their allocation in renewable energy. Solar photovoltaics are in this context considered to be one of the technologies that could rapidly be rolled out, with both building-integrated as well as free-field photovoltaic systems needed to reach these ambitious goals. There are strong arguments for prioritizing photovoltaics on buildings, as they make use of land that is already sealed, and the environmental impact is considered lower as fewer resources might be needed for the structures holding the panels. However, since there is limited literature available to back this claim with quantitative data, this paper presents a comparative study of the structures needed to implement rooftop versus free-field photovoltaic applications. With a detailed life cycle analysis, several commonly used structures have been analyzed in relation to their environmental impact. The findings show that the impact on resources can be up to 50% lower in rooftop systems compared with free-field applications but that a series of site- and material-related factors need to be considered to prioritize one system over another on a regional scale. This study thus aims at providing fact-based decision support for strategic considerations related to photovoltaic implementation plans. [ABSTRACT FROM AUTHOR]

The integration of small-scale Photovoltaics (PV) systems (such as rooftop PVs) decreases the visibility of power systems, since the real demand load is masked. Most rooftop systems are behind the metre and cannot be measured by household smart meters. To overcome the challenges mentioned above, this paper proposes an online solar energy disaggregation system to decouple the solar energy generated by rooftop PV systems and the ground truth demand load from net measurements. A 1D Convolutional Neural Network (CNN) Bidirectional Long Short-Term Memory (BiLSTM) deep learning method is used as the core algorithm of the proposed system. The system takes a wide range of online information (Advanced Metering Infrastructure (AMI) data, meteorological data, satellite-driven irradiance, and temporal information) as inputs to evaluate PV generation, and the system also enables online and offline modes. The effectiveness of the proposed algorithm is evaluated by comparing it to baselines. The results show that the proposed method achieves good performance under different penetration rates and different feeder levels. Finally, a transfer learning process is introduced to verify that the proposed system has good robustness and can be applied to other feeders. [ABSTRACT FROM AUTHOR]

The electricity crisis is a common issue in Bangladesh; however, recently the electricity scenario has been getting worse due to various reasons including power generation and distribution all over the country. Meanwhile, the large number of people requires a huge amount of energy which is not possible to be met by the national grid due to the limited power generation from different plants. Among all renewable energy sources, the solar photovoltaics (PV) system is the best choice as a generation source, either off-grid or with a grid-tied connection, to reduce the pressure on the national grid. In Bangladesh, there are more than 175,000 schools, and it is possible to generate a huge amount of renewable (solar) power to supply all the schools by using rooftop PV systems. We propose a new approach that combines solar energy harvesting and savings to make the schools self-sufficient and energywise. We performed a Hybrid Optimization Model for Multiple Energy Resources (HOMER) pro simulation and find that it was possible to generate approximately 200 megawatts (MW) of power. We conducted a feasibility study on generating power from rooftop PV systems on school buildings and reduced the power consumption using retrofitted thin-film-coated glass by around 16–20% per day depending on the school size, which can help the national power grid system by either making all the schools off-grid or grid-connected to supply power to the national grid. In addition, we perform a HelioScope simulation to investigate the maximum upscaling of PV sizing for the rooftops of school buildings in Bangladesh to realize how to make each school a mini solar power station in the future. The HelioScope simulation performance showed that it was possible to generate approximately 96,993 kWh per year from one school building.

This paper explores the potential of rooftop solar PV to meet the electricity demand in the urban areas of Abha city, Saudi Arabia (KSA), minimising imports from the grid. A localised energy system for Abha is proposed that considers two types of loads: (i) residential loads with a monthly aggregated energy consumption of 172,440 MWh and an electric demand of 239.5 MW, and (ii) commercial loads with a monthly aggregated energy consumption of 179,280 MWh and an electric demand of 249 MW. The grid currently supplies this load. This paper proposes a PV development planning tool for residential and commercial areas to calculate the total PV production for each type of load to achieve a balanced energy area, considering (i) the number of buildings, (ii) the type of load, (iii) the peak load, and (iv) the total PV array area in m2 per building. The results of the modelling study using real data demonstrate that the anticipated total PV production in residential and commercial areas is sufficient to meet local peak demand, and there is an excess of power that can either be stored locally or exported to the grid. [ABSTRACT FROM AUTHOR]

Realizing urban energy systems with net-zero CO2 emissions by 2050 is a major goal of global societies in building sustainable and livable cities. Developing cities hold a key to meeting this goal, as they will expand rapidly in the next decades with increasing energy demand, potentially associated with rising CO2 emissions and air pollution if fossil fuels continue to be utilized. Therefore, identifying equitable, cost-effective, and deep decarbonization pathways for developing cities is essential. Here, we analyzed Bangkok City, Thailand, using the System Advisor Model (SAM) for techno-economic analysis to evaluate the decarbonization potential of rooftop photovoltaics (PV) integrated with electric vehicles (EVs) as batteries on a city scale. The analyses took into consideration hourly local weather conditions, electricity demand, electricity tariffs, feed-in-tariffs, degradation, declining costs of PV and EV, etc., specific to Bangkok. As the prices of PV and EVs decrease over the next several decades, the "PV + EV" system may provide a basis for new urban power infrastructure with high energy efficiency, low energy cost, and large CO2 emission reduction. The results show that the "PV + EV" scenario in 2030 has the highest CO2 emission reduction of 73% from electricity and vehicle usage, supplying 71% of the electricity demand of the city. The "PV + EV" system may reduce energy costs by 59% with estimated technology costs in 2030. Most of the energy generated from rooftop PV is consumed owing to large EV battery capacities, which can contribute to the rapid decarbonization of Bangkok City by 2050. [ABSTRACT FROM AUTHOR]

Abstract The integration of small-scale Photovoltaics (PV) systems (such as rooftop PVs) decreases the visibility of power systems, since the real demand load is masked. Most rooftop systems are behind the metre and cannot be measured by household smart meters. To overcome the challenges mentioned above, this paper proposes an online solar energy disaggregation system to decouple the solar energy generated by rooftop PV systems and the ground truth demand load from net measurements. A 1D Convolutional Neural Network (CNN) Bidirectional Long Short-Term Memory (BiLSTM) deep learning method is used as the core algorithm of the proposed system. The system takes a wide range of online information (Advanced Metering Infrastructure (AMI) data, meteorological data, satellite-driven irradiance, and temporal information) as inputs to evaluate PV generation, and the system also enables online and offline modes. The effectiveness of the proposed algorithm is evaluated by comparing it to baselines. The results show that the proposed method achieves good performance under different penetration rates and different feeder levels. Finally, a transfer learning process is introduced to verify that the proposed system has good robustness and can be applied to other feeders.

Solar energy from rooftop photovoltaic (PV) systems in Australia’s National Electricity Market (NEM) has been continuously increasing during the last decade. How much this change has affected power demand from electricity networks is an important question for both regulators and utility investors. This study aims to quantify the impact of rooftop solar energy generation on spot electricity demand and also to forecast power system load in the post-covid-19 era. Using half-hourly data from 2009 to 2019, we develop a novel approach to estimate rooftop solar energy generation before building regression models for wholesale electricity demand of each state. We find that the adoption of solar PV systems has significantly changed the levels and intra-day patterns of power demand, especially by reducing daytime power consumption from the grid and creating a “duck curve”. The results also show that most states in the NEM would see decreased electricity demand during 2019–2034.

Focusing on the adoption of rooftop solar photovoltaics (PV) by high-income households and businesses in the Western Cape, South Africa, the article analyzes its effects on the hybridization of urban electricity systems and the ability of municipalities to drive a just transition in cities where inequality remains very high. By reducing municipal electricity sales, decentralized solar technologies threaten the surpluses generated from charges paid by grid customers, which are essential to subsidize electricity services for the poor and support other municipal services. Based on fieldwork in four Western Cape cities, the paper shows that municipalities are implementing a variety of local arrangements (regulatory, tariff, and technical) to control distributed electricity generation and are seeking, with mixed success, to avoid a post-carbon transition model that undermines grid benefits by creating a new energy divide. [ABSTRACT FROM AUTHOR]

Developing rooftop photovoltaic (PV) has become an important initiative for achieving carbon neutrality in China, but the carbon reduction potential assessment has not properly considered the spatial and temporal variability of PV generation and the curtailment in electricity dispatch. In this study, we propose a technical framework to fill the gap in assessing carbon reduction potential through remote sensing data-driven simulations. The spatio-temporal variations in rooftop PV generations were simulated on an hourly basis, and a dispatch analysis was then performed in combination with hourly load profiles to quantify the PV curtailment in different scenarios. Our results showed that the total rooftop PV potential in China reached 6.5 PWh yr−1, mainly concentrated in the eastern region where PV generation showed high variability. The carbon reduction from 100% flexible grids with 12 h of storage capacity is close to the theoretical maximum, while without storage, the potential may be halved. To maximize the carbon reduction potential, rooftop PV development should consider grid characteristics and regional differences. This study has important implications for the development of rooftop PV and the design of carbon-neutral pathways based on it. [ABSTRACT FROM AUTHOR]

A 30 kWp rooftop solar photovoltaic (PV) power plant was modelled using energy balance equations, 3-year energy production and its economic return is calculated according to the feed-in tariff agreement. Hourly measured electricity generation and Excel spreadsheet simulation results were closely compatible. The system generated 45.35 MWh, 47.05 MWh and 46.34 MWh of energy in year 1, 2 and 3, respectively. It has been observed that the performance ratio of the PV system varies between 84.50 % and 90.27 %, while the capacity factor varies between 17.26 % and 17.63%. While 93.90 MWh of electrical energy has been injected into the grid over a 3-year period, 46.40 MWh of energy has been taken from the grid. The price of electricity injected and consumed was calculated according to the FIT conditions at the time the system was installed, and the payback period was calculated as approximately 6 years. [ABSTRACT FROM AUTHOR]

The current high energy consumption can cause scarcity as Indonesia's population growth has increased quite significantly. Alternative energy is needed to anticipate energy problems in the future. Solar energy is one of the options given the most significant potential for energy produced in Indonesia. This research aims to see the strategies that PLN can do to increase the use of Rooftop PV in Indonesia based on the results of the analysis that has been done. The approach to this research is a qualitative approach with the SWOT and FGD methods. Also, the data used are primary data from survey results on Rooftop PV users in Indonesia. The SWOT analysis results show that PLN is in quadrant I, which means it has an extreme market position. PT PLN has the potential to increase the use of Rooftop PV in Indonesia. Two strategic points can be carried out by PLN, namely, carrying out vertical integration and diversifying conglomerates. Also, the researcher has proposed several alternative strategies, namely the upstream (manufacturing) development plan, the downstream (consumer) development plan, and the internal development plan.

This paper proposes a comprehensive framework for estimating the regional rooftop photovoltaic (PV) potential. The required rooftop information is extracted from Gao Fen-7 satellite images. In particular, the rooftop area is obtained using a semantic segmentation network. The azimuth and inclination angles are calculated based on the digital surface model. In addition, to improve the accuracy of the economic evaluation, buildings are divided into commercial and industrial buildings and residential buildings. Based on the difference in the roof inclination, the rooftops can be divided into flat roofs, on which the PV panels are installed with the optimal inclination angle, and sloped rooftops, on which the PV panels are installed in a lay-flat manner. The solar irradiation on the plane-of-array is calculated using the isotropic sky translocation model. Then, the available installed capacity and generation potential of the rooftop PV is obtained. Finally, the net present value, dynamic payback period, and internal rate of return are used to evaluate the economic efficiency of the rooftop PV project. The proposed framework is applied in the Da Xing district of Beijing, China, with a total area of 546.84 km2. The results show that the rooftop area and available installed capacity of PV are 25.63 km2 and 1487.45 MWp, respectively. The annual rooftop PV generation potential is 2832.23 GWh, with significant economic returns.

This paper reports on modelling outcomes for improvements to building energy performance in Indonesia. Long-term climate effects due to building energy demand and carbon emissions are also considered. The global change assessment model (GCAM) was used to generate the related end-user building energy data, including socioeconomics, for urban areas of Indonesia. As a comprehensive study, the total life cycle of carbon in the building sector and the concept of zero-carbon buildings, including energy efficiency, zero-emissions electricity and fuel-switching options, were considered. Building shell conductance (U-value) of the building envelope, floor area ratio (FAR), air conditioner (AC) efficiency, electrical appliance (APL) efficiency, rooftop photovoltaic (PV) performance and ground source heat pump (GSHP) systems were considered as parameters to mitigate carbon emissions under the operational energy category in the GCAM. Carbon mitigation associated with the cement production process was considered in the raw material category. Urban population and labour productivity in Indonesia were used as base inputs with projected growth rates to 2050 determined from the available literature. Low growth rate ‘LowRate’ and high growth rate ‘HighRate’ were considered as variable inputs for U-value, FAR, AC efficiency, APLs efficiency and PV capacity factor to model emissions mitigation. The energy consumption of the GSHP was compared to the conventional reverse cycle ACs to identify the potential of the GSHP as a fuel-switching option. In the GCAM, the benchmark (base case scenario) data set was generated based on input parameters (urban population and labour productivity rate) only for the residential building sector in Indonesia. Total potential carbon emissions mitigation was found to be 432 Mt CO2-e for the residential building sector in Indonesia over 2020–2050. It was found that an average of 24% carbon emissions mitigation could be achieved by 2020–2030 and 76% by 2031–2050.

Improving air quality, reducing greenhouse gas emissions, and achieving independence from fossil fuels have led most countries towards deploying solar photovoltaics (PV) in the power distribution grid and electrifying the transportation fleet. Internal combustion engine (ICE) vehicles are, in particular, one of the main culprits of injecting greenhouse gas emissions into the atmosphere, making electric vehicles (EVs) an important tool in combating climate change. Despite their considerable environmental and economic benefits, the integration of PVs and EVs can introduce unique operational challenges for the power distribution grid. If not coordinated, high penetration of PVs and EVs can result in variety of power quality issues, such as instances of overvoltage and undervoltage, frequency fluctuations, and/or increased losses. This paper proposes a mixed-integer multi-objective nonlinear optimization model for optimal energy dispatch in a power distribution grid with high penetration of PV and EV resources. The model proposed here is an extension of the traditional voltage and var optimization (VVO) into a comprehensive and coordinated control of voltage, active power, and reactive power. A modified version of the IEEE 123-bus test distribution system is used to demonstrate the effectiveness of the proposed solution. [ABSTRACT FROM AUTHOR]

The electricity crisis is a common issue in Bangladesh; however, recently the electricity scenario has been getting worse due to various reasons including power generation and distribution all over the country. Meanwhile, the large number of people requires a huge amount of energy which is not possible to be met by the national grid due to the limited power generation from different plants. Among all renewable energy sources, the solar photovoltaics (PV) system is the best choice as a generation source, either off-grid or with a grid-tied connection, to reduce the pressure on the national grid. In Bangladesh, there are more than 175,000 schools, and it is possible to generate a huge amount of renewable (solar) power to supply all the schools by using rooftop PV systems. We propose a new approach that combines solar energy harvesting and savings to make the schools self-sufficient and energywise. We performed a Hybrid Optimization Model for Multiple Energy Resources (HOMER) pro simulation and find that it was possible to generate approximately 200 megawatts (MW) of power. We conducted a feasibility study on generating power from rooftop PV systems on school buildings and reduced the power consumption using retrofitted thin-film-coated glass by around 16–20% per day depending on the school size, which can help the national power grid system by either making all the schools off-grid or grid-connected to supply power to the national grid. In addition, we perform a HelioScope simulation to investigate the maximum upscaling of PV sizing for the rooftops of school buildings in Bangladesh to realize how to make each school a mini solar power station in the future. The HelioScope simulation performance showed that it was possible to generate approximately 96,993 kWh per year from one school building. [ABSTRACT FROM AUTHOR]

Building a smart energy system to promote photovoltaic (PV) utilization has become an important task for cities to achieve a low-carbon future. With a focus on the rooftop PV integrated with the electric vehicle (EV) system (PV + EV), this study developed a framework to simulate the interaction between the PV + EV systems and load and evaluate the energy–environment–economic influences at the city level. Shenzhen, China, was used as a case study. The results showed that with EVs batteries providing storage service to PV, PV self-consumption can be significantly improved from 78% in the PV only system to 95% in the PV + EV system by 2030. The system can supply 37% of the total power demand in Shenzhen, which is double the current electricity generation capacity. With reduced grid power consumption and oil combustion in vehicles, citywide CO 2 emissions can be reduced by 42%. Avoided expenditures on fuel and electricity outweigh the additional capital investment of PV and EVs, leading to a total net cost savings of 21%. Compared to the PV system alone, the PV + EV system could provide more comprehensive benefits for Shenzhen. The analytical framework is generalizable to most cities in China and abroad that have yet to experience an increase in EV uptake. [ABSTRACT FROM AUTHOR]

Hybrid energy systems with renewable energy penetration have become popular solutions to improve energy security and realize the carbon neural target in urban areas. In this paper, a holistic framework is proposed for the sustainable development of a neighborhood-scale energy system integrating rooftop PV and waste-to-energy technologies. Under this framework, potential assessment of local renewable energy, optimization approach, and sensitivity analysis are integrated for the optimal design and management of the hybrid energy system with uncertain analysis. Besides, the economic, efficiency, and environmental performance under grid-connected and off-grid operation modes are compared. This proposed framework is applied to a neighborhood area in Beijing. The results show that the grid-connected hybrid energy system will still rely on traditional energy supply with low cost but great carbon emissions. In the off-grid mode, 11 % of the rooftop area will be encouraged to deploy PV panels, which satisfying 39 % of the total electricity demand. Moreover, although decreasing the PV capital cost, raising the electricity price, and increasing carbon emission penalty cost will stimulate the development of local renewable energy, compulsive renewable energy penetration policy is more effective to promote the traditional energy system transformation and reduce carbon emissions. • A holistic framework for optimizing the neighborhood-scale energy system was presented. • A hybrid energy system with the integration of rooftop PV and waste-to-energy was proposed. • The impacts of operation modes, energy policies, and uncertain parameters were investigated. • Technical, economic, and environmental performance of hybrid energy systems was evaluated. [ABSTRACT FROM AUTHOR]

This paper describes the optimization of energy conversion when solar radiation occurs at peak power conditions, namely at 11.00 am to 2.00 pm where the position of the sun is parallel to the layout of the PV Rooftop installation. The panels used are 5 units with the type of polycrystalline with a capacity of 1 panel unit consisting of 250 Wp. The position of the panels installed on the roof of the Andalas University building is based on an angle of 90o degrees with a position of ±255m above sea level. The advantages obtained when placed on the roof of the building are due to the minimal impact of shadow effects and environmental disturbances. Data retrieval using DC current and voltage sensors is then connected to the Arduino Uno microcontroller which is then interfaced in graphic form. Considerations in the installation of PV by reviewing the weather conditions at that time where the conditions were sunny and the air was clean with the aim that the performance when solar radiation entered the solar cells could be produced more optimally. Based on the data obtained at peak power, PV can convert DC power to 972.56 Wp. In the final stage of collecting data recorded on this PC, it can later be used as a reference for installing solar panels for household electricity scales in the West Sumatra region.

The increase in the share of renewable energy in the power generation mix plays a pivotal role in the decarbonisation of power systems, thus facilitating the achievement of international and national targets for reducing greenhouse gas emissions and addressing climate change. Due to the intermittent nature of variable renewable energy, the integration of these sources in power systems requires investments in additional solutions and setting strategies to ensure grid stability and reliability. For that purpose, a prospective modelling was applied to the relatively isolated island named Procida, located in the gulf of Naples in Italy, through the bottom-up optimization model TIMES-Procida for a long-term energy plan where technical solutions, i.e., deployment of photovoltaics on rooftops and storage, and policy scenarios, i.e., energy efficiency, were used to analyse the evolution of the energy system. The introduction of renewable energy could be much more relevant when dealing with islands; they appear as decisive territories for experimentation and analysis of the transformation of all power systems. At year 2050, our results address decarbonisation and energy autonomy. They show that only with high shares of renewable energy will the territory see a noticeable decarbonisation of its economic sectors (up to 24%) and a decreasing dependency on imports (−16.6% compared to low renewable integration). By comparing the results of scenarios including or lacking storage solutions, we showcased how this reflected on the investments in PV and on grid congestion relief. [ABSTRACT FROM AUTHOR]

Solar energy is a renewable energy source that can be used as a source of electricity using a photovoltaic (PV) system to reduce our dependence on fossil energy. This paper discusses an overview of the use of a rooftop PV system in accordance with applicable regulations in Indonesia. Computer simulation was conducted to determine the potential power and output energy of the rooftop PV system in the city of Surabaya. The simulation was carried out by SolarGIS Pvplanner software. Mathematical equations are derived to estimate the unit price of electric energy for the PV system, and the calculations are done numerically. The simulation results show that the total daily energy average generated from the 3 kWP roof solar PV system in Surabaya is about 13 kWh. Meanwhile, the unit price for PV system electricity is obtained between 0.08 USD - 0.11 USD / kWh.

This paper explores the potential of rooftop solar PV to meet the electricity demand in the urban areas of Abha city, Saudi Arabia (KSA), minimising imports from the grid. A localised energy system for Abha is proposed that considers two types of loads: (i) residential loads with a monthly aggregated energy consumption of 172,440 MWh and an electric demand of 239.5 MW, and (ii) commercial loads with a monthly aggregated energy consumption of 179,280 MWh and an electric demand of 249 MW. The grid currently supplies this load. This paper proposes a PV development planning tool for residential and commercial areas to calculate the total PV production for each type of load to achieve a balanced energy area, considering (i) the number of buildings, (ii) the type of load, (iii) the peak load, and (iv) the total PV array area in m2 per building. The results of the modelling study using real data demonstrate that the anticipated total PV production in residential and commercial areas is sufficient to meet local peak demand, and there is an excess of power that can either be stored locally or exported to the grid.

Solar photovoltaic (PV) technology stands out as a cornerstone in Bangladesh's journey towards achieving net-zero emissions, representing a crucial building block in the country's sustainable energy transition plan. However, rapid land use change and the lack of suitable land for developing PV pose significant barriers to achieving Bangladesh's renewable energy targets and decarbonisation goals towards a net-zero transition. Our analysis of the predevelopment land use state of ten existing solar PV plants in Bangladesh reveals a substantial use of scarce agricultural land for their establishment. Therefore, to identify pathways for overcoming the challenges, this study reassesses Bangladesh's geographic and technical potential for solar PV using geospatial modelling by considering local contexts. Our investigation encompasses Rooftop PV (RPV), Ground-mounted PV (GPV), Floating PV (FPV), and Agrivoltaic (APV) systems. To identify suitable areas and quantify potential, we employ a comprehensive exclusion model and system-specific suitability models using the QGIS platform. Utilising the latest spatial datasets, including footprint data comprising approximately 20 million buildings, a 10 metre (m) resolution land cover map, and bathymetry data, our study provides a robust analysis. The results of our models present a holistic view of Bangladesh's solar PV potential, estimating about 30 GWp for RPV, 9 GWp for GPV, 5 GWp for FPV, and 81 GWp for APV applications. Given the escalating urbanisation in Bangladesh, our findings recommend diversifying solar PV deployment with a focus on RPV and other PV systems that offer dual use of land to facilitate a smoother energy transition towards sustainable development. [Display omitted] • System-specific Solar PV potential assessment for Bangladesh's net-zero transition. • Analysis of existing 10 solar PV plants reveals design practices in Bangladesh. • The estimate uses the latest 10-m land cover and 20 million building footprints. • The country has more Rooftop PV potential than ground-mounted systems. • Dual-use PV systems can address land scarcity concerns for a net-zero transition. [ABSTRACT FROM AUTHOR]

The current high energy consumption can cause scarcity as Indonesia's population growth has increased quite significantly. Alternative energy is needed to anticipate energy problems in the future. Solar energy is one of the options given the most significant potential for energy produced in Indonesia. This research aims to see the strategies that PLN can do to increase the use of Rooftop PV in Indonesia based on the results of the analysis that has been done. The approach to this research is a qualitative approach with the SWOT and FGD methods. Also, the data used are primary data from survey results on Rooftop PV users in Indonesia. The SWOT analysis results show that PLN is in quadrant I, which means it has an extreme market position. PT PLN has the potential to increase the use of Rooftop PV in Indonesia. Two strategic points can be carried out by PLN, namely, carrying out vertical integration and diversifying conglomerates. Also, the researcher has proposed several alternative strategies, namely the upstream (manufacturing) development plan, the downstream (consumer) development plan, and the internal development plan. [ABSTRACT FROM AUTHOR]

Rooftop Photovoltaic (RTPV) systems have gained more interest due to modularity and environmental friendliness. This article proposes an RTPV system for fulfilling the load demand of the main campus of Assuit University. The proposed system's economic and technical feasibility is comprehensively explored, including the expense and reliability. The system's sizing is implemented as a constrained optimization challenge. Particle Swarm Optimization (PSO) is employed to identify the proposed RTPV modules' optimal quantity, considering expanding Assuit University until 2025. Robust and reasonably accurate load forecasting models are developed and examined, including medium and long terms, to identify the monthly/annual load peaks from 2019 to 2025. The sizing procedure's PSO outcomes are validated via their comparison with Software such as PVsyst and PVGIS. The results indicated the economic efficacy of the proposed RTPV system and the ability of PSO to yield improved sizing than the other Software because of the well-formed objective function.

Turkey, which has immense solar potential, has recently shifted towards solar energy and new renewable energy deployment regulations, including implementation and commercializing rooftop PV technologies. Thus, these require a detailed assessment to determine the power source's capability and convince the policymakers. To the authors' best knowledge, there is no available data or a city-based study for the rooftop PV potential in Turkey. Here, we present the first city-based rooftop PV potential study in Ankara. The technical PV potential calculations are sensitive to the suitable area ratio, module efficiency, and module area assumptions. This study proposes a new, free, reliable, and open-source model for estimating the rooftop PV potential, and it is adaptable to every roof type. The suitable roof area for PV panels is calculated using Helioscope software. Five different modules with different efficiencies and module sizes are modelled in Helioscope. The results showed that Ankara's total technical PV potentials for residential, public, and commercial buildings are 1.15 TWh/year, 55 GWh/year, and 26.8 GWh/year, respectively. Best results are obtained by Mono-Si Halfcut (M 2) and Thin Film (M 5) modules in residentials, M 2 and Mono-Si Bifacial Modules (M 3) in Public and Commercial Buildings. • Technical potential highly depends on the suitable area, module size and efficiency. • Estimation of potential varies due to building and roof type. • Technical potential can be increased by prudential roof designing in new buildings. • Around 463,000 people's annual electricity demand can be supplied in Ankara. • A combination of different modules can increase potential according to roof type. [ABSTRACT FROM AUTHOR]

Renewable energy sources and the possible sustainability that can be achieved through them has become a common discourse in the world today. The Middle East and Northern African countries have high potential to benefit from large scale renewable energy projects. These nations may initiate or permit the use of residential rooftop photovoltaic (PV) systems in the near future. However, data regarding system design, grid compatibility, and consumption of energy produced through rooftop photovoltaic systems is insufficient. The supporting policies and a feed-in tariff lack, thereby creating more research and development issues. Therefore, this research study aims to use the ten most populated nations in the Middle East and Northern Africa to (1) compare the use of rooftop PV systems in ten populated cities and (2) to evaluate the economic viability of rooftop PV systems under varying policies and electricity rate schemes. The findings of the study can help policymakers understand the application of rooftop PV systems in the Middle East and Northern African countries. The study, the first of its kind, uses an economic model to evaluate rooftop PV systems in ten identical houses in ten of the most populated cities in the Middle East and Northern African countries.

Realizing urban energy systems with net-zero CO2 emissions by 2050 is a major goal of global societies in building sustainable and livable cities. Developing cities hold a key to meeting this goal, as they will expand rapidly in the next decades with increasing energy demand, potentially associated with rising CO2 emissions and air pollution if fossil fuels continue to be utilized. Therefore, identifying equitable, cost-effective, and deep decarbonization pathways for developing cities is essential. Here, we analyzed Bangkok City, Thailand, using the System Advisor Model (SAM) for techno-economic analysis to evaluate the decarbonization potential of rooftop photovoltaics (PV) integrated with electric vehicles (EVs) as batteries on a city scale. The analyses took into consideration hourly local weather conditions, electricity demand, electricity tariffs, feed-in-tariffs, degradation, declining costs of PV and EV, etc., specific to Bangkok. As the prices of PV and EVs decrease over the next several decades, the “PV + EV” system may provide a basis for new urban power infrastructure with high energy efficiency, low energy cost, and large CO2 emission reduction. The results show that the “PV + EV” scenario in 2030 has the highest CO2 emission reduction of 73% from electricity and vehicle usage, supplying 71% of the electricity demand of the city. The “PV + EV” system may reduce energy costs by 59% with estimated technology costs in 2030. Most of the energy generated from rooftop PV is consumed owing to large EV battery capacities, which can contribute to the rapid decarbonization of Bangkok City by 2050.

The utilization of cropland and rooftops for solar photovoltaics (PVs) installation holds significant potential for enhancing global renewable energy capacity with the advantage of dual land-use. This study focuses on estimating the global area suitable for agrivoltaics (PV over crops) and rooftop PVs by employing open-access data, existing literature and simple numerical methods in a high spatial resolution of 10 km × 10 km. For agrivoltaics, the suitability is assessed with a systematic literature review on crop-dependent feasibility and profitability, especially for 18 major crops of the world. For rooftop PV, a non-linear curve-fitting method is developed, using the urban land cover to calculate the PV-suitable built-up areas. This method is then verified by comparing the results with open-access building footprints. The spatially resolved suitability assessment unveils 4.64 million km ^2 of global PV-usable cropland corresponding to a geographic potential of about 217 Terawatts (TW) in an optimistic scenario and 0.21 million km ^2 of rooftop-PV suitable area accounting for about 30.5 TW maximum installable power capacity. The estimated suitable area offers a vast playground for energy system analysts to undertake techno-economic assessments, and for technology modellers and policy makers to promote PV implementation globally with the vision of net-zero emissions in the future.

Improving air quality, reducing greenhouse gas emissions, and achieving independence from fossil fuels have led most countries towards deploying solar photovoltaics (PV) in the power distribution grid and electrifying the transportation fleet. Internal combustion engine (ICE) vehicles are, in particular, one of the main culprits of injecting greenhouse gas emissions into the atmosphere, making electric vehicles (EVs) an important tool in combating climate change. Despite their considerable environmental and economic benefits, the integration of PVs and EVs can introduce unique operational challenges for the power distribution grid. If not coordinated, high penetration of PVs and EVs can result in variety of power quality issues, such as instances of overvoltage and undervoltage, frequency fluctuations, and/or increased losses. This paper proposes a mixed-integer multi-objective nonlinear optimization model for optimal energy dispatch in a power distribution grid with high penetration of PV and EV resources. The model proposed here is an extension of the traditional voltage and var optimization (VVO) into a comprehensive and coordinated control of voltage, active power, and reactive power. A modified version of the IEEE 123-bus test distribution system is used to demonstrate the effectiveness of the proposed solution.

Mauritius relies heavily on fossil fuel imports to satisfy the energy requirements of its population. Urged by policies to address climate change at the national and international levels, the government is committed to promote sustainable development, with emphasis laid on reducing greenhouse gas emissions. Consequently, we provide an assessment of rooftop PV potential at the national level. A sampling strategy is used to acquire reduction coefficients, which are thereafter applied to energy-based equations. The result suggests that the rooftop PV potential at the country-scale is estimated at 20.04 GW with an annual energy output of 32,512 GWh. A novel architectural layout for a Solar City to be located at an identified optimum site is proposed. A shading analysis is conducted to verify the appropriateness of the city's structural design to harness energy from the sun. An energy analysis performed, reveals that the Solar City has a solar power potential of 13.55 MW and an annual energy generation capacity equivalent to 21.99 GWh. Construction of the Solar City would help avert the emissions of 13,744 tons of CO2 annually. [ABSTRACT FROM AUTHOR]

Cities are expected to be protagonists of the energy transition and, among other challenges, the decarbonation of the residential consumption could greatly benefit from photovoltaic generation in the built environment. To assess its potential, the present study analyses the possibility to cover the electric demand of the city of Valencia with rooftop-installed PV panels. Specific types of buildings has been selected to study the potential of each one of them with respect to their demand and with a specific production/consumption model. The total potential energy production for the city of Valencia is estimated to be enough to satisfy the demand of domestic electricity. The economic investment scenario has been analysed (best- and worst-case scenarios), and the corresponding environmental benefits have been studied. The results of the present article are encouraging in the context of a global energy transition, necessary in the present times to keep human consumption within the planetary limits. • Potential energy generation with rooftop PV panels has been estimated. • Rooftop PV can cover almost completely the domestic electricity demand. • Best- and worst-case scenarios for economic investments have been estimated. • Environmental considerations and emission estimations are reported. [ABSTRACT FROM AUTHOR]

Developing rooftop photovoltaics has become an important pathway towards carbon neutrality globally, but how to rationally implement rooftop photovoltaic development has not been investigated. This study presents a technical framework for optimizing the development scale and spatial layout of rooftop solar installations based on high-resolution generation simulation and load-oriented electricity dispatch. It is demonstrated that with the gradual expansion of rooftop development, its penetration in the electric grid grows at a decelerated speed, but the accompanying curtailment increases at an accelerated rate. Both regional sub-grid integration and improved grid flexibility marginally increase the development scale under curtailment constraint, while energy storage and trans -regional power transmission allow for significantly larger scales, thus elevating the penetration of photovoltaic generation to higher levels. The analysis reveals that the development scale should be optimized to account for regional differences in load characteristics. The optimal layout that maximizes photovoltaic penetration while minimizes photovoltaic curtailment varies with the grid flexibility and storage capacity. In China, at least 90% grid flexibility and 8–12 hours of storage capacity are required to realize 2/3 photovoltaic penetration and meet a 5% curtailment constraint. This study provides guidance for rooftop photovoltaic development in China and has implications for variable energy management in the community. • A framework is established for optimizing the scale and layout of rooftop photovoltaics. • Energy storage and load shifting support significantly larger development scales. • Scale and layout should be optimized to account for regional load differences. • At least 90% grid flexibility 8–12 h of storage capacity are necessary in China. [ABSTRACT FROM AUTHOR]