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This paper examines the potential of solar and hydrogen (H 2) energy-based hybrid energy systems for residential applications. The growing need for energy and the demand for sustainable energy sources have led to the development of integrated energy systems that combine renewable energy resources to meet energy needs. This paper overviews recent studies on hybrid energy systems for on-grid and off-grid residential utilizations. It discusses the system configuration and components of hybrid energy systems, including solar panels, electrolyzers, fuel cells (FC), and batteries. It also covers the technical optimization of integrated energy systems, including sizing, control strategies, and economic analysis. The key findings of this review paper indicate that hybrid energy systems can offer dependable and sustainable energy for residential applications. Through numerical analyses, the optimal dimensioning of the system elements and control strategies can significantly enhance the system's performance and lower the cost of energy. This study also highlights the challenges and opportunities for integrating hybrid energy systems within residential applications. Overall, it provides in-depth perspectives on the possibilities inherent in solar and hydrogen energy-based hybrid energy systems for residential applications. The findings can guide future research and the advancement of hybrid energy systems for sustainable energy solutions. • Comprehensive review on solar and hydrogen-based residential applications. • Holistic approach to system configuration, optimization, and economics. • Detailed analysis of interconnected components enhancing system efficiency. • Unique focus on real-world residential applications and scenarios. • Broad applicability across diverse geographical regions. [ABSTRACT FROM AUTHOR]

Converting surplus electricity into hydrogen is considered a promising way for accommodating large-scale wind or solar power. However, it is expensive to establish a new-built hydrogen network or storage facilities at the current stage. Hydrogen-enriched compressed natural gas (HCNG), a mixture of natural gas and hydrogen, can be an alternative approach to consuming surplus renewable energy in the short-medium term. This paper investigates the feasibility of establishing an electricity-gas-hydrogen coupled energy system by modeling the HCNG network, power grid, and hydrogen electrolyzer in Ireland with consideration of pipeline characteristics. The economic analysis based on the planning results of the coupled system is presented in detail. When the hydrogen injection ratio reaches 20% at the HCNG stations, the system operating cost and carbon emission can be reduced by 24.2% and 6.4%, and 100% wind can be consumed. • A detailed modeling method for HCNG pipeline pressure drop and line pack is proposed. • An EGH-IES planning model encompassing entire HCNG supply chain is established. • A case study is conducted based on the real energy system in Ireland. [ABSTRACT FROM AUTHOR]

Green H 2 (GH) has emerged as a highly promising medium for the transportation of eco-friendly energy. The utilization of H 2 as the primary operational medium in H 2 -based energy storage systems and fuel cells has facilitated the integration of these systems with various other renewable energy sources, rendering such integration highly viable. This review presents an overview of the current advancements in the field of GH production techniques using water electrolyzers powered by renewable energy sources. The present paper starts with a concise overview of several production techniques and a detailed analysis of various types of water electrolyzer. It also offers a thorough examination of H 2 production methods utilizing solar, wind, and hybrid systems. An economic evaluation of GH production was analyzed by comparing the costs associated with different renewable sources. This study focuses on investigating the challenges and advantages of GH and the implementation of large-scale commercial operations. The proton exchange membrane water electrolyzer (PEMWE) technologies boast higher current densities (1-2Acm−2) than alkaline water electrolyzer (AWE); the PEMWE technologies also produce a higher purity of H 2 up to 99.9999 %. The wind energy-associated PEM LCOH ranges from 5.3 to 9.29 $/kg. AWE had levelized cost of H 2 (LCOH) of 7.49–7.59 $/kg. Other studies show that SOE-based LCOH ranges from 6 to 9.34 $/kg and should drop to 1.9 $/kg by 2050. The cost of GH was found to be significantly influenced by the rated wind speed compared to other wind turbine parameters, and it ranged from $1.7/kg to $40.00/kg. [Display omitted] • GH could help reduce global warming and transition to a more sustainable energy system. • Discussion on grand challenges, prospects, and key recommendations to the commercialization of water electrolysis systems. • The lack of global hydrogen standards hinders the growth of the global hydrogen market. [ABSTRACT FROM AUTHOR]

Green hydrogen (GH 2) is produced using renewable energy resources (RERs) such as solar photovoltaic (PV) and wind energy. However, relying solely on a single source, H 2 production systems may encounter challenges due to the intermittent nature, time-of-day variability, and seasonal changes associated with these energies. This paper addresses the assessment of mega-scale solar-wind complementarity and the economic viability of large-scale H 2 production and storage in Algeria, considering various climatic conditions. A techno-economic feasibility analysis is conducted by examining various factors, including resource complementarity, electricity and hydrogen productivity, solar and wind contributions, capacity factors (CFs), total net present cost (TNPC), the levelized cost of hydrogen (LCOH) production, and storage (LCOS). The findings reveal that among the studied locations (Tamanrasset, M'sila, Hassi R'mel, and Adrar), Tindouf ranked first in H 2 production, with the highest amount at 11,267 kg and the lowest LCOH at 2.999 $/kg. Wind energy accounted for 69% (3,846,922 kWh) of the total (5,572,571 kWh), while solar energy contributed 31% (1,738,171 kWh). Economically, the LCOH-TNPC for the various locations ranged from 2.99 $/kg-77,042,696 $ to 3.70 $/kg-99,000,488 $. The total electricity-hydrogen generated is estimated at 25,840.251 MWh-529,395 kg. Wind power makes the major contribution, accounting for 63%–70%, compared to the PV system's share, ranging from 31% to 37%. Compared to relying on a single source, leveraging solar-wind complementarity presents opportunities for more consistent energy utilization and reliable hydrogen production. The obtained results are essential for decision-makers and policymakers in Algeria, indicating that the country can successfully achieve energy diversification and transition for future sustainability, and become a major player in the international hydrogen market. [Display omitted] • Mega-scale solar-wind assessment for energy-H 2 production and storage in Algeria. • Feasibility analysis with techno-economic criteria (H 2 productivity, CF, TNPC, LCOH). • LCOH ranges from 2.99 to 3.707 $/kg and TNPC from 77,042,696 to 99,000,488 $. • Tindouf site achieves highest H 2 production and lowest LCOH: 114,267 kg, 2.999 $/kg. • Wind CF is nearly double that of PV, ranging from 34.3 to 44.1%, contributing 63–70%. [ABSTRACT FROM AUTHOR]

The extensive use of coal and oil for heating, electricity generation and cooling of buildings contributes to various environmental problems, both locally and globally. One of the feasible solutions to the climatic issues currently in this region is using sustainable energy sources. Hydrogen is an alternative option to fossil resources generated from sustainable energy sources. It is a form of energy that is both ecologically safe and sustainable. Hydrogen may now be produced in several different ways, including by reforming hydrocarbons, the Electrolysis of water, and Steam reforming of fossil fuels. However, because there is a finite supply of fossil fuels and a change in climate conditions due to the emission of CO 2 & other contaminants, there has been a focus on producing hydrogen using renewable resources. This study reviews an H 2 production system that combines geothermal & solar energy, the two primary renewable energy sources and a hybrid solar-geothermal system. This study looked into different aspects, like the working fluid for water electrolysis, the geothermal fluid temperature, and the type of power cycle. Comparative analysis was also performed on numerous GPPs, including flash, ORC cycles, binary, flash-binary, and solar collectors; this covers investigations on the rates and costs of producing hydrogen. • This paper looks at three different approaches of producing hydrogen using renewable energy sources. • An innovative renewable energy system that depends on solar and geothermal power. • An integrated system consists of geothermal and solar energy, an electrolyzer, and a fuel cell unit. • Hydrogen production as a function of design factors including working fluid, electrolysis temperature, and cycle type. • Producing hydrogen from geothermal and solar energy is a cost-effective and potentially profitable solution. [ABSTRACT FROM AUTHOR]

This paper focuses on the design and use of a control system for a renewable energy production plant based on hydrogen. The proposed control system aims at ensuring the stability and smooth functionality of the plant, which consists of a (i) photovoltaic system connected to an electrolyzer through a battery, (ii) a DC/DC step down transformer, and (iii) an electrolyzer heat exchange system. In this study, solar irradiance is the main system input, and hydrogen production the main output. Since the system utilizes solar energy as input, it depends on the random input of solar irradiance, ambient temperature, and wind flow. Furthermore, the electrolyzer's functionality is subject to several operational variables including cell voltage, current, temperature, and pressure. The electrolyzer heat exchange system operates at specified water temperatures and flow rates. The DC/DC output voltage, and therefore the voltage supplied to the electrolyzer, is regulated by changing its duty cycle. To regulate hydrogen production in the renewable energy production plant, an efficient control system is required. Accordingly, in this work, a control system is designed accounting for three different electrolyzer technologies, alkaline, PEM (proton exchange membrane), and E-TAC (electrochemical - thermally activated chemical water splitting). Subsequently, the effectiveness of the control system is analyzed using Matlab and Simulink models. The main results indicate that the battery is a crucial element in the whole system as it supplies the necessary energy to the electrolyzer. By regulating the appropriate components, the proposed control system proved capable of minimizing power fluctuations and increasing system efficiency up to 20% depending on ambient conditions. Additionally, the results indicate E-TAC and PEM efficiencies 13% and 7% higher than alkaline, respectively. [Display omitted] • Design of a control system for three different electrolyzer technologies. • Use of control systems for electrolyzer voltage and heat exchange. • Photovoltaic system connected to an electrolytic one through a battery. • Proposed control system increases system efficiency up to 20%. [ABSTRACT FROM AUTHOR]

Solar photovoltaic thermal system (SPTS) can fully tap solar energy resources to realize thermal and electric supply for users simultaneously, but the volatility and uncertainty of renewable energy and load cause the imbalance of energy supply. This paper proposes a multi-time scale optimal scheduling method for SPTS based on event-triggered model predictive control (ET-MPC) considering battery performance deterioration. Firstly, SPTS is divided into day-ahead and day-in optimization layers from different time scales. Day-ahead scheduling takes the minimization economic cost as the optimization function to obtain pre-scheduling plan, and day-in scheduling adapts rolling optimization scheme based on model predictive control (MPC) to reduce power fluctuations and achieve optimal scheduling adjustment. Moreover, the battery performance decay parameter is introduced into the MPC model and embedded into the optimization problem to prolong the cyclic life deterioration, and an event-triggered mechanism is introduced into MPC to improve the computational efficiency and reduce the communication frequency. Finally, the results show that the proposed double-layer scheduling method improves 4.15 %, 66 % and 13.39 % respectively regarding cost, power fluctuation and battery maintenance, and improve the calculation efficiency of 48.89 % compared with standard MPC method, which indicates that the proposed method has good economy, stability and execution efficiency. • This paper proposed energy scheduling for solar photovoltaic thermal system (SPTS). • Double-layer optimal scheduling is proposed to realize the economy and stability. • Battery service time is prolonged through defining performance index. • An event-triggered mechanism is introduced to MPC to reduce the communication burden. • The proposed method improves performance from different perspectives. [ABSTRACT FROM AUTHOR]

Buildings have significantly contributed to high energy demand (30.3%) and GHG emissions (26.1%) worldwide. Consequently, many developed countries have set carbon-neutral targets for 2050, mandating that all new constructions thereafter be designed as net-zero emission buildings (NZEBs). To achieve this goal, one of the most practical sources of renewable energy, solar power, is employed in this study to estimate the economic feasibility of implementing NZEBs in the non-residential sector of the United States. While past studies have typically estimated the economic payback period of solar power technology by assuming fixed values for "PV energy conversion rates (%)" and "investment costs ($USD)", this paper carefully investigated the economic feasibility of "solar-based NZEBs" by precisely tracking these dynamic future changes in PV panels. These techno-economic variables were carefully predicted using a statistical technique known as the five-parameter logistic (5 PL) function. The results show that Site 4 is the only solar region suitable for implementing "PV-integrated NZEBs", reaching a payback period of 8.44 years in 2040 (Scenario 1). Furthermore, with small technological improvements in PV energy efficiency (%), buildings located in Site 3 and Site 4 can meet the net-zero emission target with payback periods of less than 10 years in 2034 (Scenario 2). Finally, starting in 2044, the "PV-integrated system" will have a payback period of approximately 7 years in most study locations, even without federal support for the solar investment tax credit (SITC). Accordingly, federal support for solar power generation will be more effective if the SITC rate is gradually reduced by 2.5% annually starting in 2033. In conclusion, this paper suggests the economic feasibility of implementing solar-based NZEBs in the United States non-residential sector by considering the synergetic effect of technological improvement and cost reduction in PV-integrated systems. • This study predicted the cost and efficiency of PV panels to estimate the economic feasibility of solar-based NZEBs. • The cost reduction and technical advancement in PV panels can remarkably improve the economics of solar power. • The 5 PL function is systematically modeled to predict the total investment cost and efficiency of PV panels. • In most study locations, solar-based NZEBs are projected to achieve a 7-year payback period beginning in 2044. • The federal support for the SITC rate (%) is recommended to be gradually lowered starting in 2033. [ABSTRACT FROM AUTHOR]

In recent times, the escalating global demand for sustainable and renewable energy sources has catalyzed the exploration and development of innovative technologies, among which floating photovoltaic (FPV) systems emerge as a particularly promising solution. These systems exploit solar energy by deploying PV panels on water surfaces. These systems, offer several advantages, including their independence from land use constraints, enhanced energy efficiency due to the cooling effect of water, and the potential for synergy with various energy sources. Expanding on prior literature reviews, this paper provides a focused review of the latest developments in FPV systems, cutting-edge technologies, challenges faced the FPV in marine settings, extending to an economic analysis for comprehensive feasibility assessment, and market potential from diverse angles. The primary objective is to promote additional research and applications of FPV to guarantee the safety and stability of FPV systems under challenging marine environmental conditions, aiming to enhance overall efficiency, reliability, and the widespread adoption of FPV projects, while concurrently reducing investment costs. Highlighting its importance for energy-deficient African countries, the paper underscores the significance of integrating FPV systems into the continent's energy strategies for widespread adoption, to bolster energy security and environmental sustainability across the continent. [ABSTRACT FROM AUTHOR]

Modern power systems integrated with renewable energies (REs) contain many uncertainties. The proposed method introduces a novel approach to address the challenges associated with wind power generation uncertainty in probabilistic load flow (PLF) studies. Unlike conventional methods that use wind speed as an input, the paper advocates for utilizing wind generator output power (WGOP) as an input to the point estimate method (PEM) in solving PLF. The uniqueness lies in recognizing the distinct behavior of wind power uncertainty, where not all random samples of wind speed contribute to actual wind power production. The paper suggests a Nataf-KernelDensity-Spline-based PEM, combining the Nataf transformation, Kernel density estimation (KDE), and cubic spline interpolation. This innovative integration effectively manages wind power correlation within the analytical framework. By incorporating spline interpolation and kernel density estimation into the traditional PEM, the proposed method significantly enhances accuracy. To validate the effectiveness of the proposed approach, the method is applied to IEEE-9 and IEEE-57 bus test systems, considering uncertainties related to load, wind power generation (WPG), solar power generation (SPG), and conventional generator (CoG) outages. Comparative analysis with Monte Carlo simulation (MCS) results demonstrates that the proposed method outperforms the conventional PEM in terms of accuracy. Overall, the paper contributes a pioneering solution that not only highlights the importance of using WGOP as an input in PLF but also introduces a sophisticated method that surpasses traditional approaches, improving accuracy in power system studies involving renewable energy integration. The accuracy of the proposed method is validated by comparing its results with those obtained through Monte Carlo simulation (MCS), where the proposed method yields more accurate results than the conventional PEM. [ABSTRACT FROM AUTHOR]

Today, wind and solar energy sources have opened their place in the power system due to their environmental appeal. With the presence of these renewable energy sources (RESs), forecasting net load (NL) and its ramp are of huge importance owing their fundamental role in evaluating and improving the flexibility of the power grid. However, it is challenging to analysis flexibility and NL ramps using NL forecasts due to the uncertainty of RESs. Furthermore, the surge in the number of electric vehicles (EVs) as notable electricity consumers, and how their charging strategy can affect the NL curve are matters of concern. Most NL forecasting and flexibility analyses overlook the concurrent integration of wind and solar sources. Moreover, the impact of controlled EVs charging on grid flexibility remains largely unexplored. Existing studies also fail to assess the proper combination of wind and solar energy sources for future flexibility needs. This paper presents a framework for forecasting NL and detecting ramps with the simultaneous presence of EVs and RESs to investigate the impact of controlled charging of EVs on flexibility. Investigating charging of EVs as a solution is delved deeply in this paper to reduce NL ramps and improve flexibility. The numerical results show that controlled EVs charging may lead to 3% ramp reduction and 52% increment in the system flexibility. This paper also proposes to forecast and find the proper combination of RESs for the next years, leading to a 75% increment in the system flexibility compared to the business as usual RESs penetration. [Display omitted] [ABSTRACT FROM AUTHOR]

Significant increases in renewable energy are needed in electricity systems in order to reduce greenhouse gas emissions, particularly in the face of increasing electricity demand arising from the electrification of heat and transport. Greater flexibility is required in the electricity system to facilitate this, using proven flexibility providers such as batteries and interconnection or new technologies yet to be proven. This paper investigates how the relationship between battery and interconnection development and carbon price can impact carbon dioxide emissions and renewable energy curtailment. The study simulates twenty-eight scenarios and sensitivities using a unit commitment and economic dispatch model of a 2030 European power system that acknowledges that coal will not be fully eliminated from the 2030 generation mix. The results show that interconnection and battery deployment can alleviate renewable energy curtailment by over 2.4 TWh for the basecase, but a high carbon price is critical to ensuring their deployment plays a complementary role in reducing emissions. The paper also examines the impact of batteries and interconnection on solar and wind energy curtailment. It reveals that battery development nearly doubled the solar energy benefits achieved by interconnection development in some cases, while wind energy benefited more from interconnection development. • A high CO 2 price is critical to IC and batteries achieving emissions reductions. • IC can facilitate production of cheaper higher emitting fuels when CO 2 price is low. • Solar energy benefits more from deployment of batteries due to similar timescales. • Diversity of wind profiles can be leveraged with increased interconnection. • Regardless of CO 2 price IC and batteries alleviate renewable energy curtailment. [ABSTRACT FROM AUTHOR]

Renewable portfolio standard is an effective administrative tool to guide the behavior of electricity producers and impact the renewable energy diffusion. However, currently the renewable energy quota is generally set to be static and the efficiency is limited. In this paper, we proposed a dynamic renewable portfolio standard policy and we aimed to analyze how it will impact the renewable energy diffusion in China. The connections between electricity producers were simulated under both the perfectly competitive market and monopoly market. And a networked evolutionary game approach is applied considering dynamic linking between the electricity producers. The results show that dynamic quota policy is effective in promoting the proportion of wind power generation from 20% to 59.17% and promoting the proportion of solar power generation from 20% to 79.25%. With the sensitivity analysis, we found that renewable energy quota and the on-grid price are the most influential parameters. The proportion will reach 76.47% if quota is 0.7 and 68.1% if on-grid price is 630 Yuan/MWh. And the influence of tradable green certificate prices and generation cost is limited in promoting renewable energy diffusion. This paper offers the Chinese government a potential implementation for the perfection of national renewable energy diffusion. [Display omitted] • Propose a novel dynamic renewable portfolio standard scheme. • Analyze the influences of different kinds of the electricity market. • Investigate parameters affecting the wind power and solar power generation. • Establish dynamic networked evolutionary game models. • Dynamic linking is considered when the connections of players change. [ABSTRACT FROM AUTHOR]

Global warming is one of the most important environmental problems in the world. One might state that the most potential considerable cause of global warming is the increase in greenhouse gas emissions in the atmosphere. The commonly suggested method used to struggle with this potential problem is to consume renewable energy sources instead of fossil fuels. In today's World, where the rate of urbanization is very high, the research on the effect of the energy demand of the residential sector on global warming has become a crucial research topic in the energy and climatic literature. Among different solar sectors, the residential sector is a major energy consumer. Considering the residential, commercial, and industrial solar sectors, the residential solar sector has become a major component of total solar energy. It accounts for approximately 43% of total solar. On the other hand, to the best of my knowledge, there exists no empirical study in the literature considering the influence of residential solar consumption on environmental quality. Thus, determining the effect of the most used energy source, residential solar, energy consumption on the environmental quality has arisen the key research problem of this paper. This research analyzes the effects of residential solar energy usage on CO 2 emissions for the period 1989:1–2020:1 in the USA. It has been observed throughout Morlet wavelet analyses that the use of residential solar energy has a strong effect on mitigating CO 2 emissions in the 1–2 year frequency. Eventually, this paper provides relevant potential energy policies that can enhance the efficiency of residential solar energy consumption. Partial wavelet coherence (RSolar-CO 2 || Coal, Hydro, IP), 1989:1–2020:1. [Display omitted] • Considers the impact of residential solar consumption (RSolar) on CO 2 emissions. • Follows the data for the USA for the monthly period 1989:1–2020:1. • Launches wavelet models in which RSolar, CO 2 , Coal, Hydro, and IP are employed. • Reaches the negative impact of RSolar on CO 2 in the USA for the period 1989:1–2020:1 at 1-2 year-cycle period. • Through potential energy policies, residential solar energy consumption efficiency should be increased. [ABSTRACT FROM AUTHOR]

Increasing the demand for water and energy resources as well as the clean energy policies and the need for pollution emission reduction has developed the research on the renewable energy resources. This paper reviews the recent advances in multi-generation units for heat, electricity, and desalinated water production. It tries to investigate the new papers in this arena which were not mentioned in the previous reviews. The main parts of this work introduce the co-generation systems for the production of "water and electricity", "heat and water", and "electricity, water, and heat". The results show that among the solar energy receiving devices, Photovoltaic/Thermal panels (PV/Ts) and parabolic trough solar collectors are the most used in co-generation systems. On the other hand, a combination of solar collectors and power cycles makes them a suitable choice for the establishment of a large-scale co-generation plant. Therefore, solar collector-based electricity and water co-generation systems have at least 10 times more output capacity than PV- or PV/T-based systems. On the other hand, most heat and water co-generation systems can achieve an output temperature of 60 °C or more and produce around 10000 kg/year of freshwater based on system size. Examining the co-generation systems of water, electricity and heat also shows that these systems have a high production capacity compared to other co-generation systems. Systems based on heliostat solar tower can produce maximum powers of more than 18 MW and fresh water of 90 kg/s. • Recent advances in solar multi-generation units are reviewed. • PV/Ts and parabolic trough solar collectors are most used collectors in cogeneration systems. • RO and MED have more applications in solar-based co-generation units. • Using waste heat can increase technical and economic performance of system. [ABSTRACT FROM AUTHOR]

• The thermal, rheological, and optical properties of ferrofluids and how they change with magnetic fields were discussed. • The utilization of ferrofluids in solar energy systems was detailed in a state-of-the-art analysis. • The recommendations aimed to optimize the use of ferrofluids and magnetic fields in energy systems to enhance performance. Solar energy technologies play a crucial role in the transition to sustainable energy sources; however, there is an ongoing challenge in optimizing their efficiency and performance. This review paper thoroughly exposes the potential for enhancing solar systems by incorporating ferrofluids and utilizing magnetic fields. It provides a comprehensive examination of the rheological, thermal, and optical properties of ferrofluids, as well as their behavior when exposed to magnetic fields. The paper emphasizes the ability of ferrofluids to improve heat transfer efficiency, adapt to changing conditions, and enable precise control in the conversion of solar energy. Furthermore, the review addresses the obstacles and limitations associated with integrating ferrofluids into solar technologies, proposing potential solutions and outlining future research directions. [ABSTRACT FROM AUTHOR]

• Prevalent quality assessment of drying materials with solar energy was reviewed. • The potential application of solar drying for high-quality dried products was introduced. • The physical and chemical mechanisms of quality transformation during drying process were clarified. Solar energy is a green and renewable clean energy. Using this as main or auxiliary energy to dry agricultural materials could reduce energy consumption and improve product quality. In the drying process of agricultural materials, not only drying technologies but also drying parameters would affect the quality of materials. This paper provides a guided technological tour on solar drying through a literature research. An overview about the drying technologies to evaluate the drying quality, such as traditional sun drying, solar tunnel drying, solar greenhouse drying, solar-assisted drying system, is presented to demonstrate advances and application potential of solar drying. Finally, variable temperature drying is preliminarily proposed and tested to verify its superiority of energy saving and drying quality improvement. The literature research in this paper gives a reference on the effective application of solar drying through specifying the mechanisms of quality transformation. [ABSTRACT FROM AUTHOR]

In recent years, harvesting solar energy as a renewable and sustainable energy source has been studied extensively across engineering fields. Having reviewed more than 50 large-scale projects of Hydronic Asphalt Pavement (HAP), this paper offers a series of findings: the range of construction cost of asphalt collector varies between 25 and 151 €/m2 and 1.760–3.000 €/m2 for the heat exchanger and the total cost. The energy harvest capacity of asphalt solar collector systems (0,6–0,8 GJ/m2/year) and the required amount of heat for snow melting projects (100–900 W/m2) vary significantly in different projects. Using grid supports for easier pipe placement and protection of pipes against heavy loads during and after construction is recommended. Pavement solar collector systems reduced carbon dioxide emissions by 8–100% in different projects by changing their source of energy from fossil fuels to renewable and sustainable sources. Moreover, in order to further evaluate the sustainability of the HAP systems, a detailed life cycle assessment is required, including all available data related to the energy performance, pavement service life, material end-of-life recycling, etc. Finally, the paper identifies the knowledge gaps requiring further research especially in the area of energy output of the HAP systems, pavement service life and life cycle assessment. • A comprehensive review of large-scale hydronic asphalt pavement projects is provided. • Potential challenges in the large-scale hydronic asphalt pavement are investigated. • Technical specifications, operational aspects and performance are explored. • Construction cost and structural response of systems are analyzed. • The projects' performance is evaluated based on energy output and sustainability. [ABSTRACT FROM AUTHOR]

The paper offers a method for developing a universal system of automated design of an optimal structure of autonomous distributed hybrid energy complexes (ADHEC) and the means for regulation of the energy balance therein, i.e. control of the power flows circulating in the mentioned system. ADHEC will not only help unload the existing power system, but can also be used to produce "green" hydrogen. In general, the design of the optimal structure of ADHEC includes the following stages (subtasks): data research and creation of a statistical database of electric loads of consumers, the wind speed in the region under consideration, the hydroelectric potential of mountain and lowland rivers, and the solar energy, as well as the research and development of a database of converters of wind and water energy into electrical energy. The paper focused on the task of designing the optimal structure of the distributed hybrid generation system that will ensure the desired level of power generation at a minimal cost and with necessary functional reliability. [ABSTRACT FROM AUTHOR]

Distributed energy systems are becoming increasingly popular worldwide. The 100% renewable energy system can be an important energy supply alternative to reduce the carbon emissions and address energy shortage, especially for remote areas. However, the performance of 100% renewable energy system (RES) at community level needs further detailed analysis, which is affected by the climates, availability of renewable energy and local energy markets. This paper proposes a design optimization framework of 100% renewable energy systems for low-density communities and investigates the system performance. To investigate the integration and performance of 100% RES, thirty typical cities located in different regions of China were chosen considering different climates, geographical features, and renewable energy distributions. By taking the economic performance as the optimization objective, the optimal design for the 100% RES is obtained, and the energy and economic performance is analyzed. Results show that, under the current energy market conditions, the 100% RES is feasible for low-density communities in most regions of China. The payback periods of the systems in most cities are less than six years. When the cost of PV is reduced by half considering future technological developments, the payback period of a 100% RES can be reduced by 30%–60%. This paper would provide design suggestions and application recommendations in regard to promoting 100% RES in China. • Application of 100% renewable energy system at community level is studied. • 30 zones are selected considering climates, renewable energy sources and markets. • Solar energy and biomass can contribute to over 90% of the total energy supply. • Investment of 100% RES can be paid back in 6 years for most regions. • Payback periods can be reduced by 30%–60% when PV technology is further developed. [ABSTRACT FROM AUTHOR]

As the solar energy utilization technology for renewable clean energy, actual parabolic trough receivers are subject to tracking errors and absorber tube installation errors, and the bellows and Kovar ring under these errors have a significant impact on the receiver's safety. Based on the MCRT-FVM-FEM principles in this paper, a receiver's optical-thermal-stress mathematical model is modeled and the thermal-stress performance and safety of the receiver's key components under two errors are evaluated. The correlation between the bellows and Kovar ring's performance and the two errors is analyzed. The results demonstrate that the lower tracking errors and larger installation errors markedly increment the absorber's deformation and have a negative impact on the receiver safety. Bellows and Kovar ring's asymmetrical temperature distribution causes variable swell and uneven stress under tracking and installation errors. Temperature gradient variation of bellows is more sensitive under errors than Kovar rings. Kovar ring's compressive stress rises substantially as the Y-directional installation error varied from −15 mm to 15 mm compared to other errors. With tracking errors exceeding 8 mrad, bellows' tensile stress and Kovar ring's compressive stress diminish under installation error. Thus, larger tracking errors significantly reduce the threat to the receiver when installation errors exist. [ABSTRACT FROM AUTHOR]

It is becoming increasingly important for human societies to use renewable energy. More effective energy storage solutions are crucial to increase the share of renewable energy in the domestic and industrial sectors, which consumes a large amount of thermal energy for heating and cooling purposes. There has been little quantitative analysis of thermal energy storage in solar-based cold production units. An efficient method of designing heat and/or cold storage systems and smart operation planning can help a cooling/heating system to be smaller for the same capacity of supply and thereby reducing the costs of initial investment and costs of operation. This paper attempts to show how the size of a heat and cold storage system affects its thermal performance and how it can lower costs and emissions. For this, a solar-assisted thermally driven cooling supply system with various designs and integrations of their cold storage unit is simulated dynamically through a whole year in Qassim region as the case study. The results show that a system design with double solar heat storage and double cold storage in parallel arrangement results in the best techno-economic-environmental performance. For this case, the levelized cost of cooling will be 383 USD/MWhr, which will be at least 3% lower than the typical hot/cold buffer tank design scenario. [ABSTRACT FROM AUTHOR]

The increase of Renewable Energy (RE) production to fight the climate crisis is posing new technological and financial challenges, due to the availability and variability of RE Sources (RES). These challenges can be addressed by selecting the most suitable mix of RES to optimise power production, to assure grid resilience and to promote local energy use. To facilitate the selection of such combination, this paper presents an original methodology that allows to compare mixing scenarios with different RES, also in presence of batteries and backup system. It simultaneously optimises the energy surplus with respect to the eventual external electrical load and the missing energy with respect to the same electrical load. This method, which can cope with isolated or plugged-to-grid systems, is here applied to a novel case study, an oil&gas platform under decommissioning, located in the Adriatic Sea (Italy). The RE production from wind, wave and solar panels is supposed to support other activities for the platform reuse, such as aquaculture, monitoring and mineral deposition. In this case, solar energy is providing the greatest contribution to the optimal mix in terms of production, while wave energy assures the most relevant contribution in terms of continuity. [ABSTRACT FROM AUTHOR]

Single-phase string inverter has been widely applied to grid-tied photovoltaic (PV) rooftop applications for its renewable energy. However, the inherent attribute of intermittency in solar energy may induce instability and unqualified power. To meet the grid-interconnection standards, high demands of efficiency and harmonic distortion need to be imposed on DC/AC inverters. Conventional soft-switching inverters used to sacrificing auxiliary resonant circuits to exchange for soft switching. This requires additional costs as well as sufficient dead time to discharge junction capacitances of all switches, which exacerbates total harmonics distortion (THD) induced by dead-time effect. To improve, this paper proposes a partial soft-switching silicon carbide (SiC) -based active neutral-point-clamped (ANPC) inverter, which possesses high efficiency, eligible dead time, and no auxiliaries. 650-V SiC MOSFET is adopted for its smaller output capacitance compared with Si device. Hybrid PWM modulation is utilized to achieve partial soft switching. Whereas, the soft switching realization range and power losses highly depend on the dead time. To achieve less power loss and improved dead time effect, this paper proposes a loss model-based dead time algorithm through a Power Loss VS. Dead Time mathematical loss model. Moreover, the mechanism of the dead time affected by soft switching is explored. The transition modes, dead time configurable boundaries, and design procedure are also analyzed in detail. A 1-kW prototype is demonstrated with the input of 800 V and the rated output of 220 V/ 4.5 A. Its efficiency could reach 99.6% with THD=0.95% at full power level. [ABSTRACT FROM AUTHOR]

In the pursuit of sustainable energy solutions, the integration of renewable energy sources and hydrogen technologies has emerged as a promising avenue. This paper introduces the Integrated Renewable Energy-Driven Hydrogen System as a holistic approach to achieve energy independence and self-sufficiency. Seamlessly integrating renewable energy sources, hydrogen production, storage, and utilization, this system enables diverse applications across various sectors. By harnessing solar and/or wind energy, the Integrated Renewable Energy-Driven Hydrogen System optimizes energy generation, distribution, and storage. Employing a systematic methodology, the paper thoroughly examines the advantages of this integrated system over other alternatives, emphasizing its zero greenhouse gas emissions, versatility, energy resilience, and potential for large-scale hydrogen production. Thus, the proposed system sets our study apart, offering a distinct and efficient alternative compared to conventional approaches. Recent advancements and challenges in hydrogen energy are also discussed, highlighting increasing public awareness and technological progress. Findings reveal a payback period ranging from 2.8 to 6.7 years, depending on the renewable energy configuration, emphasizing the economic attractiveness and potential return on investment. This research significantly contributes to the ongoing discourse on renewable energy integration and underscores the viability of the Integrated Renewable Energy-Driven Hydrogen System as a transformative solution for achieving energy independence. The employed model is innovative and transferable to other contexts. [Display omitted] • Integrating renewable energy and hydrogen for energy independence. • Advantages of Integrated Renewable Energy-Driven Hydrogen System: Zero emissions, resilient energy. • Economic viability: Payback period of 2.8–6.7 years. • Technological progress in hydrogen energy. • A novel and transferable system dynamics model for sustainable solutions is proposed. [ABSTRACT FROM AUTHOR]

There is a growing interest in renewable energy sources cause the worsening impact of fossil fuel development and abuse on the ecological environment. Solar collectors are major facilities that utilize solar energy, many studies and techniques have been employed to increase the efficiency of the collectors. This paper aims to evaluate the thermal performance of an evacuated tube solar collector(ETSC) in the solar thermal system by using Al 2 O 3 , CuO, Fe 3 O 4 and Multi-walled carbon nanotube(MWCNT) nanofluid as working fluids. An evaluation approach for the energy, exergy and entropy of ETSC were proposed. Furthermore, the energy gained and stored by nanofluid in the solar collector was also been studied. The ETSC shown highest energy and exergy efficiency when the 0.01 vol%-MWCNT nanofluid was used which was 33.1% higher than that of water, and it was the same situation of exergy efficiency while the highest was 3.17 under the optimum situation. In addition, the energy gained by 0.01 vol%-MWCNT nanofluid showed the highest potential of energy absorption than other nanofluid, the maximum exergy destruction and entropy generation were achieved when water was used as working fluid of solar collector while the lowest were observed when MWCNT nanofluid with 0.01 vol% was used. Compared to normal working fluid in the ETSC, the use of nanofluid with high thermal conductivity can save more fossil fuels and coals which have a positive effect on protecting the environment. [ABSTRACT FROM AUTHOR]

• An overview of solar photovoltaic (PV) power generation in respect of all the other renewable energy sources (RES) have been presented on cumulative basis. • The different solar PV configurations, international/ national standards and grid codes for grid connected solar PV systems have been highlighted. • The state-of-the-art features of multi-functional grid-connected solar PV inverters for increased penetration of solar PV power are examined. • The various control techniques of multi-functional grid-connected solar PV inverters are reviewed comprehensively. The installed capacity of solar photovoltaic (PV) based generating power plants has increased significantly in the last couple of decades compared to the various renewable energy sources (VRES). As a result, the increased penetration of solar PV-based generating units leads to several issues related to power quality, system stability, and reliability. In view of these concerns, various international standards and grid codes have been amended to address such critical issues. Therefore, most solar PV-based generating units have undergone several changes in operational and control structure. Subsequently, varieties of solar PV configurations and control structures have been proposed by several researchers to augment the desired operational features. This paper presents a comprehensive review of various solar PV configurations, control strategies, and ancillary services with multifunctional features within this context. The utilization and benefits of various configurations and their practical aspects have been discussed thoroughly for all the configurations and architectures. Apart from this, the control aspects of grid-connected solar PV systems are categorized into two important segments, namely, a) DC-side control and b) AC-side control. This article covers the important features, utilization, and significant challenges of this controller and summarizes the advanced control techniques available in the literature. Further, the various control techniques have been compared concerning different operational parameters, such as controller gains, duties, and selector quantities in tabular form with ready references. Furthermore, the concerns related to power quality, stability, and reliability of various techniques have been included for understanding the applicability of grid-connected PV systems. In the end, a detailed comparison of some available industrial inverters concerning their power ratings, voltage ratings, configurations, and advanced functions incorporated are also presented, which will help the researchers, academicians, and practicing engineers. [ABSTRACT FROM AUTHOR]

In this paper, a 2.25 kWp grid integrated with the tied solar park has been implanted in the Renewable Energy Applied Research Unit (URAER) in a dry and harsh desert region. The PV plant uses micromorph thin-film solar modules (a-Si/μc-Si) technology. The photovoltaic module systems (PVS) were evaluated from May 2015 to December 2020 (around five and a half years of operation), and the electricity was injected into the internal network of the low-voltage power supply. Performance evolution has been conducted in this work as stated by the IEC61724 guideline. The monthly and annual performance indicators analyzed and assessed consist of reference yield, array yield, final yield, system losses, capture losses, PV module efficiency, system efficiency, inverter efficiency, capacity factor, and performance ratio. The annual electricity production is 3688.28 kWh, 3188.25 kWh, 3306.28 kWh, 3136.05 kWh, and 2952.81 kWh for 2016, 2017, 2018, 2019, and 2020 operating periods, respectively. The solar park's total produced energy yield over the monitored period and the quantity of CO 2 emissions avoided are 16,271.67 kWh and 14.17 tons, respectively, which can significantly contribute to and help in purifying the environment from pollution. In addition, the energy results produced by the PVS were compared to those found by the four widely used PV simulation tools (PVsys, PVGIS, NREL's PVWatts® Calculator and Solar Med-Atlas). Furthermore, this work investigates and quantifies the degradation phenomenon of solar PVS power output after five years and a half years of outdoor exposure. There is around 0.22 % degradation per year. When this rate was compared to other studies conducted worldwide, it was shown to be highly appropriate. Technical-economic research was also conducted, revealing that the system's PVS period, which establishes its sustainability, is between 9 and 12 years. The results demonstrate that micromorph thin-film modules perform better and are more efficient under harsh real-world outdoor environmental conditions. Inventux modules preserve most of their better performance even with increasing module temperature. This kind of PV module technology is low-insensitive to the highest PV module temperature. Compared to the literature, micromorph thin-film technologies are better and preferable than crystalline modules under desert environmental conditions. The results also indicate that grid-connected solar park plants using this kind of technology are feasible in the hot arid climate to produce electricity and may participate in future energy projects in the country. • This study investigates the performance of a pilot grid-tied solar power station located in the southern region of Algeria, which has been operating in the harsh desert climate. • Data recorded between May 2015 and December 2020 was used to evaluate the system's performance, and the results were compared to those obtained from four simulation tools. • The study found that the micromorph thin-film module technology from Inventux Company was the most reliable and potent option for this site, with better performance and resistance to changes in temperature. • The system's annual electricity production and CO 2 emissions were recorded for five operating periods, and degradation in solar PV power output after six years of outdoor exposure was quantified, with a degradation rate of 1.10%/year. • Technical-economic research indicated that the system had a payback period of 9-12 years, making it a feasible option. • The findings will provide useful guidelines for decision-makers, engineers, and industrial companies interested in large-scale solar photovoltaic systems in hot, harsh semi-arid climates. [ABSTRACT FROM AUTHOR]

[Display omitted] • Standard solar collectors' absorber geometry modification by inserting V-grooves. • Optimizing solar collectors based on the geometric modification was demonstrated. • Importance of the absorbing surface geometry combined with spectral selectivity. • Improvement of the efficiency of the collectors despite increasing the thermal losses. • Efficiency improvement up to 5.61%, considering a V-groove opening angle of 60°. Solar energy plays an essential role in the process of the energy transition to renewable sources, and so too do technological innovations for exploring these energy sources, and for improving the thermal efficiency of conventional flat solar collectors. This study set out to model, simulate, and investigate the effect of modifying the geometry of the absorber plate of standard solar collectors for heating liquids, by inserting V corrugations. This leads to making consequent modifications to geometrical and optical parameters that improve the efficiency of the equipment. This paper presents the application of a mathematical-graphical model that seeks an optimum incidence angle to corrugate an absorber plate. This model, based on available optical experimental data, was built to improve the efficiency of solar collectors. During its application, an investigation could be made of the effect of the corrugation on the radiation and on the convection coefficients, the correlations of which were introduced into the mathematical model, and some of them were neither mentioned nor used in previous publications. A case study was carried out to investigate the behavior of three different collectors and the improvement in the efficiency of these collectors. It was shown that by using V grooves the efficiency was improved for all three flat solar collectors studied. As seen, the geometric modification contributes to improving efficiency when associated with selective absorption layers of solar collectors. The combination of both strategies can enhance the thermal efficiency of solar collectors and this can be further explored by researchers and manufacturers. [ABSTRACT FROM AUTHOR]

This paper performs a thermo-economic assessment of a multi-generation system based on solar and wind renewable energy sources. This system works to generate power, freshwater, and hydrogen, which consists of the following parts: the solar collectors, Steam Rankine subsystem, Organic Rankine subsystem, desalination part, and hydrogen production and compression unit. Initially, the effects of variables including reference temperature, solar radiation intensity, wind speed, and solar cycle mass flow rate, which depend on weather conditions and affect the performance of the integrated system, were investigated. The thermodynamic analysis results showed that the overall study's exergy efficiency, the rate of hydrogen and freshwater production, and total cost rate are 33.3%, 7.92 kg/h, 1.6398 kg/s, and 61.28 $/h, respectively. Also, the net power generation rate in the Steam and Organic Rankine subsystems and wind turbines are 315 kW, 326.52 kW, and 226 kW, respectively. The main goal of this study is to minimize the total cost rate of the system and maximize the exergy efficiency and hydrogen and freshwater production rate of the total system. The results of optimization showed that the exergy efficiency value improved by 20.7%, the hydrogen production rate increased by 1%, and the total cost rate value declined by 2%. Moreover, the optimum point is similar to a region in Hormozgan province, Iran. So, this region is proposed for building the power plant. • Propose a renewable-based system to produce power, hydrogen, and freshwater. • Conducting a thermo-economic and parametric analyses of the system. • Employing a multi-objective optimization algorithm to find the optimum values. • Finding the optimum exergy efficiency and total cost rate of 42% and 62.5 $/h. • Selecting the best place in Iran where is closest to the optimum results. [ABSTRACT FROM AUTHOR]

The production of hydrogen is still a major challenge, due to the high costs and often also environmental burdens it generates. It is possible to produce hydrogen in emission-free way: e.g. using a process of electrolysis powered by renewable energy. The paper presents the concept of a research, experimental stand for the storage of renewable energy in the form of hydrogen chemical energy with the measurement methodology. The research involves the use of proton exchange membrane electrolysis technology, which is characterized by high efficiency and flexibility of energy extraction for the process of electrolysis from renewable sources. The system consist of PV panel, PEM electrolyzer, battery, programmable logic controller system and optional a wind turbine. Preliminary experimental tests results have shown that the electrolyzer can produce in average 158.1 cc/min of hydrogen with the average efficiency 69.87%. • Zero-emission hydrogen production is possible. • Hydrogen production using a proton exchange membrane (PEM) electrolyzer for Polish conditions. • Proposal for experimental studies on hydrogen production. [ABSTRACT FROM AUTHOR]

Renewable energy attracts increasing attention from both industry and academia under the context of carbon neutrality. For wind and solar energy, the strong dependence on natural processes results in the imbalance between energy production and real demands. Energy storage technologies, e.g., Compressed Air Energy Storage (CAES), are promising solutions to increase the renewable energy penetration. However, the CAES system is a multi-component structure with multiple energy forms involved in the process subject to high temperature and high-pressure working conditions. The CAES system is a complex process flowsheet consisting of charging and discharging process. The process should be optimized to achieve the best thermodynamic and economic performance. Under the optimal design conditions, it might lead to severe consequences once a failure occurs, e.g., harm to humans, the environment, and assets. Limited attention and scarce available information have been paid to the CAES system risk management yet. Hence, this paper applies the System-Theoretic Process Analysis (STPA), which is a top-down method based on system theory, to identify the CAES system safety hazards. The results are expected to provide a preliminary guideline for practitioners regarding the safety and reliability of the CAES system. As a result, a more reliable CAES system can contribute to a more flexible energy system with more efficient and economic utilization of fluctuating renewable energy. [ABSTRACT FROM AUTHOR]

The combination of biomass and solar energy in the combined cooling heating and power (CCHP) system is conducive to reducing carbon dioxide emissions of the system. To improve the system's economic performance under the punishment of carbon tax, this paper optimizes the system from system design and operation strategies. A hybrid renewable energy CCHP system with shaft power distribution structure of an internal combustion engine (ICE) is proposed. By optimizing the shaft power distribution of ICE, the direct drive heat pump is realized, and the efficiency of the shaft power of ICE is improved. A double-layer optimization method considering the long and short-term benefits is proposed based on the system, fully improving the system economy in design and operation. The case study shows that the CCHP system reduces the annual cost by 40.37% and the CO 2 emission by 88.93% compared with the separate production system. Compared with the non-shaft power distribution system, the maximum daily operation cost is saved by 557.11CNY. Compared with the hourly optimization method, the proposed optimization method based on total daily benefit reduces the annual cost by 7.73% and CO 2 emission by 35.87%, and the utilization rate of the energy storage device is higher. [ABSTRACT FROM AUTHOR]

[Display omitted] • Areas with the potential of Brackish water resources were identified. • To identify the type of water sources, the soil type investigation method was used. • The energy required for RO water desalination devices is supplied by sunlight. • The potential of solar power plant in Iran was calculated to generate electricity. • Four factors were used to identify suitable areas. Iran has 985,798 square kilometers of desert areas, equivalent to 59.8 percent of the country's total area. This factor causes the creation of salt marshes and, accordingly, the salinization of surface and groundwater. For the first time in this paper, an indirect method is presented to identify areas of Brackish water sources with 3000–10000 mg/L TDS in the entire country of Iran and simultaneously identify the area's potential in terms of the solar energy to provide energy for desalination by reverse osmosis devices. Other types of sources of water, such as seawater, which has more salinity than Brackish water (about 35000 mg/liter) are not investigated in this research, because the primary purpose of this article is to use water that exists in the form of ponds, wells, or surface water that water cannot be used for residential or agricultural purposes, at the same time, this water is not seawater. Simultaneously 16 data layers that include economic, environmental, technical, and geological parameters have been considered.The proposed methodology provides a structured decision aid, which can be used in other countries to identify the mentioned areas and produce fresh water using reverse osmosis devices. Geographic Information Systems (GIS) are used to generate layers of data and to apply the elimination criteria and constraints. Multiple Criteria Decision Analysis (MCDA) is then used to rank and sort the grids via the identified evaluation criteria. This research can also have two other applications. The first is for professionals who want to identify areas with saline water potential, and the second is for organizations that want to launch reverse osmosis desalination plants that work with solar renewable energy. Technically, there are about 160 cities in Iran that have an area of about 144440685120.498077 square meters, have saline water sources, and simultaneously have the potential to use solar energy as one of the renewable energy sources to power reverse osmosis desalination devices. Most of these areas are located in the east of Iran and these areas have high water stress. In this research, the city of Khansar with an area of 95917147.16 square meters, which is located in the province of Isfahan and in the central part of Iran, has surface and underground saline water resources that both technically and operationally, has the highest potential. [ABSTRACT FROM AUTHOR]

The growing demand of renewable energy sources in the energy sector has a considerable impact on the development of stand-alone solar photovoltaic (PV) systems. Three-port converter (TPC) topologies are widely used as a gateway between solar PV, energy storage, and loads. This paper proposes a three-port converter with buck and boost operating modes. The topology is SEPIC-based rather than the conventional buck-boost or Cuk circuit, hence eliminates the inverting output and reduce the input current ripple. The series capacitor in a SEPIC converter endows the TPC with inherent protection against short-circuit output. The TPC has four modes of operation: Dual Output (DO) mode, Dual Input (DI) mode, Single Input Single Output-1 (SISO-1) mode and Single Input Single Output-2 (SISO-2) mode. The power flow management algorithm employs a mode-specific voltage regulation strategy that distributes the duty cycle for each switch via time-sharing control scheme. Small signal model of the TPC is developed in each operating mode and based on this, voltage controller parameters are derived. When the TPC changes modes, the algorithm modifies the controller parameters to the mode-specific values. The proposed system is implemented by utilising the FPGA Cyclone-III comprising the Nios-II processor core with necessary hardware intellectual property (IP) forming a System on a Programmable Chip (SoPC). The system is evaluated in real time using a 120W solar PV as the energy source and lead-acid battery as the storage. [ABSTRACT FROM AUTHOR]

This paper proposes a maiden intelligent controller design that consists of a fuzzy proportional-integral-derivative-double derivative (FPIDD) controller whose parameters are fine-tuned using the Gradient-Based Optimization algorithm (GBO). The proposed FPIDD2 regulator is employed as a secondary regulator for stabilizing the combined voltage and frequency loops in a two-area interconnected power system. The proposed FPIDD2 controller is tested in a two-area hybrid system, with each area comprising a mix of traditional (thermal, gas, and hydraulic power plants) and renewable generation units (wind and solar power). Additionally, the proposed controller takes into account system nonlinearities (such as generation rate limitations and governor deadband), system uncertainties, and load/renewables changes. The dynamic responses of the system demonstrate that FPIDD2 has superior ability to attenuate the deviations in voltage and frequency in both areas of the system. In the investigated hybrid system, the suggested FPIDD2 is compared to a GBO-tuned integral derivative tilted (ID-T) controller and FPID controller. As a fitness function for the GBO, the criteria of minimizing the integral time absolute error (ITAE) are applied. The results are presented in the form of MATLAB/SIMULINK time-domain simulations. The simulation outcomes prove that the presented controller has an outstanding performance compared with the other control strategies in the dynamic response of the system in terms of rising and settling times, maximum overshoot, undershoot values and ITAE. The ITAE value of the FPIDD2 regulator tuned by the GBO technique was enhanced by 90.9% with the GBO-based ID-T and 55.4% with GBO-based FPID controllers. [ABSTRACT FROM AUTHOR]

• The study makes the following main contributions: • 1) A mathematical layout is developed to include renewable resources for load scheduling in digital twin-based microgrids. • 2) Uncertainty modelling of PV production employing Beta PDF for load scheduling is utilized in digital twin environment. • 3) The load scheduling algorithm employing RL for minimizing the energy bills regarding a renewable resource is developed. Utility companies recognize the importance and necessity of demand response (DR) programs for reducing the increased production costs associated with rising energy demand. The advent of smart information and communication systems has made DR programs on the basis of cost a viable option to control load in smart microgrids. Small domestic consumers are rapidly using stochastic renewable energy resources such as photovoltaic (PV). The study examines an integrated layout for residential load scheduling or load commitment problems (LCP) with renewable energy resources no matter what kind of tariff is applied. Uncertainty-based decision-making problems are effectively solved using reinforcement learning (RL). The paper proposes an RL-enabled solution to the LCP in smart microgrids. An innovative aspect of the study is the development of an integrated layout containing an implementable solution that takes into account user satisfaction, stochastic renewable power, and tariffs. In simulation tests, the suggested layout is tested for its effectiveness and flexibility. An analysis of the algorithm's efficiency using a household user with schedule-able and non-schedulable devices, together with a PV resource, has been presented. [ABSTRACT FROM AUTHOR]

In the present paper a techno-economic hydrogen production and transportation costs to export from Colombia to Europe and Asia were determined using the open-source Python tools, such as WindPowerLIB, PVLIB, ERA5 weather data, and the Hydrogen-2-Central (H2C) model. Calculations were performed as well for Chile, for comparison as a regional competitor. In addition, a detailed overview of Colombia's energy system and national efforts for a market ramp-up of renewable energy and hydrogen is provided. The application of the model in different scenarios shows Colombia's potential to produce green hydrogen using renewable energies. The prices estimated are 1.5 and 1.02 USD/kgH 2 for 2030 and 2050 with wind power, and 3.24 and 1.65 USD/kgH 2 for 2030 and 2050 using solar energy. Colombia can become one of the most promising hydrogen suppliers to Asian and European countries with one of the lowest prices in the production and transportation of green hydrogen. [Display omitted] • Open-source models were used to obtain costs of H 2 production and transportation. • LCOH of green H 2 using wind energy is 1.63 and 1.11 USD/kgH2 by 2030 and 2050. • LCOH of green H 2 using solar energy is 3.72 and 1.89 USD/kgH2 by 2030 and 2050. • Exporting H 2 to Asia by 2030 and 2050 costs 3.47 and 2.9 USD/kg, respectively. • Exporting H 2 to Europe by 2030 and 2050 costs 3.1 and 2.55 USD/kg, respectively. [ABSTRACT FROM AUTHOR]

Hydrogen drives the big wheel of nature. Hydrogen nuclear fusion in the sun produces light and heat. Solar flux reaching the earth's surface in an hour is far more than global annual energy demand. Photosynthesis traps 100-TW solar energy annually into biomass on land at 0.1% efficiency that is about six times more than global yearly energy demand. All photosynthetic organisms (photoautotroph) annually convert 100-billion tons of carbon in the atmosphere into biomass. The rampant rise in energy demand requires to replicate natural photosynthesis process artificially to convert solar energy and Carbon dioxide (CO 2) in liquid and burnable gaseous fuels. Chemists, physicists and biologists are collaborating to develop suitable catalysts for artificial photosynthesis. There is a consensus the sun can fuel transport sector by hydrogen and power grid by photo-electricity. It is well in time to develop a full spectrum of solar technologies instead of keeping ourselves plugged to hydrocarbon honey. Photocathodes and catalysts can mediate water splitting using nature-inspired artificial photosynthesis. Economic hydrogen production can accomplish the grand energy transition from fossil fuels to sustainable and renewable energy sources. This paper reviews the recent advances in artificial photosynthesis technologies and presents our work on the microbial fuel cell for hydrogen production and points out technical barriers and operational challenges. • Photosynthesis traps about 100-TW solar power, six times larger than the power consumption of all human civilizations. • Economic hydrogen production can accomplish the grand energy transition from fossil fuels to renewable energy sources. • This paper presents original work on Microbial Fuel Cell for hydrogen production with barriers and operational challenges. [ABSTRACT FROM AUTHOR]

A power system with 80% renewable energy sources (RES) requires significant provision of flexibility to balance the deviations of fluctuating solar and wind power. This paper focuses on how a smart mix of renewable generation technologies can reduce the demand for flexibility and therefore the overall system costs. To measure the demand for flexibility in systems with high RES generation, the term flexibility is defined and described using predictable indicators such as the difference between the highest and the lowest residual demand or the number of hours with negative residual load during a year. This definition is required to determine the optimal mix of RES installations. Optimization is performed for Germany based on the grid development plan of the transmission system operators. In contrast to most studies of the future energy system that foresee a further expansion of onshore wind, this paper shows that higher shares of offshore wind and, to some extent, photovoltaic are better suited to reducing the demand for flexibility and thus the cost of integrating fluctuating RES into the system. • Extended definition of flexibility demand for power systems based on renewables. • Offshore wind and photovoltaic requires less flexibility than onshore wind. • Uncertainty about the future renewable mix increases system integration costs. • Challenge: trade-off between levelized cost of generation and system integration. [ABSTRACT FROM AUTHOR]

An ever-increasing interest on integrating solar power to utility grid exists due to wide use of renewable energy sources and distributed generation. The grid-connected solar inverters that are the key devices interfacing solar power plant with utility play crucial role in this situation. Although three-phase inverters were industry standard in large photovoltaic (PV) power plant applications, the microgrid regulations increased the use of single-phase inverters in residential power plants and grid interconnection. This paper presents a detailed review on single-phase grid-connected solar inverters in terms of their improvements in circuit topologies and control methods. Even though there are many reviews have been proposed in the current literature, this study provides a differentiating approach by focusing on novel circuit topologies and control methods of string and micro inverters. The single and multi-stage solar inverters are reviewed in terms of emerging DC-DC converter and unfolding inverter topologies while the novel control methods of both stages have been surveyed in a comprehensive manner. The isolated and transformerless circuit topologies have been investigated by reviewing experimental and commercial devices. The soft computing, evolutionary and swarm intelligence based algorithms have been summarized in MPPT methods section while current injection and grid-connection control methods of unfolding inverters stage have been presented with and without PLL architecture. There are many papers have been compared and listed in each section to provide further outcomes which is followed by a summarizing discussion section and conclusion. [ABSTRACT FROM AUTHOR]

Hydrogen production from renewable energy sources appears to be an interesting solution for reducing greenhouse gas emissions and ensuring the energy security supply. This paper develops an integrated framework to evaluate land suitability for hydrogen production from solar energy site selection that combines multi-criteria decision making (MCDM) with geographical information systems (GIS); an application of the proposed framework for Algerian country. In GIS two types of criteria will be taken: constraints and weighting criteria. Constraints criteria will make it possible to reduce the area of study by discarding those areas that prevent the implementation of installing solar hydrogen production systems. These criteria will be obtained from the legislation (land use, water bodies, waterways, roads, railways, power lines, and also their buffer around them). Weighting criteria will be chosen according to the objective to be reached, in this case they will be the hydrogen demand, potential solar hydrogen production, digital elevation models (DEMs), slope, proximity to roads, railways, and power lines. Through the use of MCDM the criteria mentioned will be weighted in order to evaluate potential sites to locate a solar hydrogen production installation system. Analysis and calculation of the weights of these criteria will be conducted using Analytic Hierarchy Process (AHP). As a result, the final index model was grouped into four categories as "very low suitability", "low suitability", "moderate suitability" and "high suitability" with a manual interval classification method. The results indicate that 10.34% (246,272.02 km2), of the study area has very low suitability, 60.75% (1,446,907.65 km2) has low suitability, 6.68% (159,100.3 km2) has moderate suitability and 0.49% (11,669.21 km2) has high suitability for a solar-powered hydrogen production installation system. The other 21.74% (517,790.5 km2) of the study area is not suitable for such projects. The sensitivity analysis highlights that the suitable sites for solar hydrogen production installation system are dependent on the weights of the criteria that influence the decision. The MCDM methodology integrated with GIS is a powerful tool for effective evaluation of the solar-powered hydrogen production sites selection. • The paper addresses the problem of site selection for solar hydrogen projects. • Land suitability index is computed to determine the best sites. • MCDM coupled with GIS is a powerful tool for effective evaluation of the solar hydrogen production sites selection. [ABSTRACT FROM AUTHOR]

In recent decades, the world's environmental troubles have become increasingly serious. Seeking new and environmentally friendly energy sources to replace chemical fuels is the key to improving environmental problems. As a renewable energy source, solar energy is the most promising and viable alternative energy source. In this paper, we present a spectrally selective solar broadband absorber with a hollow cylindrical microstructure. The model uses Ti film-Al2O3 film-Cu film as the substrate and Ti–Al2O3–Ti–Al2O3 (in the order from top to bottom) materials stacked to form hollow cylinders as the microstructure. The model was simulated using the FDTD Solutions software from Lumerical Solutions. From the simulation results, it can be seen that the absorption rates of the model in the solar radiation band 280 nm–4000 nm are all above 90%, and the average absorption rate is 94.1%; under the light of AM 1.5, the weighted average absorption rate is 94.8%. In addition, the reflectivity of the model in the 6516 nm–20000 nm band is all higher than 80%, with an average reflectivity of 94.2%, and the average reflectivity in the non-solar radiation band of 4000 nm–20000 nm is 85.4%, which has good thermal infrared suppression ability. In addition, we discovered the physical mechanism of model broadband absorption by analyzing the electric field distribution maps at different wavelengths. At the same time, the model has polarization insensitivity and wide-angle absorption properties. The excellent spectral selectivity allows this solar broadband absorber to operate in high temperature environments, which is very meaningful for the research of both solar thermophotovoltaic technology and thermal insulation and cooling materials. In this paper, we present a spectrally selective solar broadband absorber with a hollow cylindrical microstructure. The model is substrate of Ti film-Al2O3 film-Cu film (top-down order), and hollow cylinders made of Ti–Al2O3–Ti–Al2O3 (top-down order) materials stacked as microstructures, with seven layers and total thickness of only 1 μ m. We use FDTD software to simulate the model. The results show that the model has an average absorption of 94.1% in the 280 nm–4000 nm band of solar radiation, an absorption bandwidth (absorption >90%) of 3720 nm, a weighted average absorption of 94.8% under AM 1.5 illumination. And the reflectivity of the model starts to increase continuously after the wavelength of 4800 nm. The reflectivity is greater than 80% in all wavelengths after 6516 nm, up to 96.5%. After numerical calculations, the average reflectivity of the model is 94.2% in the 6516 nm-20,000 nm band and 85.4% in the 4000 nm-20,000 nm band outside the solar radiation band. This shows that the model has good spectral selectivity and thermal infrared suppression. [Display omitted] • Ultra-wideband high-efficiency solar absorber based on hollow cylindrical microstructures-. • The solar broadband absorber achieves excellent spectral selectivity and thermal infrared suppression. • The absorber has excellent polarization insensitivity and wide angle absorption characteristics. [ABSTRACT FROM AUTHOR]

The curtailment of renewable energy worsens with increasing penetration in power systems, so it is necessary to explore the upper limit value of the penetration of renewable energy (PRE). This paper uses artificial neural networks (ANN) to study the historical data of California independent system operator (CAISO), analyze the fluctuation balance strategy of wind and solar power, and predict the upper limit value of the PRE, which will peak at 40.5% in 2025. In addition, this paper also simulates the inclusion of energy storage unit (ESU) with an installed capacity of 3 GWh in the grid to reduce curtailments, and analyzes the grid operating conditions and the upper limit value of the PRE, showing that the storage units with an installed capacity of only 3% of the average daily power output of solar energy recover 58% of the annual curtailments (2021), and the maximum PRE is 41.2%. [ABSTRACT FROM AUTHOR]

Water scarcity is a major global challenge, with 2.3 billion people living in water-stressed countries and the potential for 700 million people to be displaced by 2030 due to widespread water scarcity. The increasing effects of climate change and overpopulation are exacerbating the problem, particularly in arid and remote regions. One potential solution is the harvesting of atmospheric water, which is estimated to be a vast source of freshwater at 12,900 km3. This study aims to provide a comprehensive and up-to-date review of the latest research in the field of atmospheric water harvesting systems. The purpose of this review is to present the various types of harvested water, the use of solar energy, the methods of gathering it, and the mathematical models used in the literature. The paper has covered numerous types of atmospheric water harvesting techniques, including harvesting dew and fog. In addition, the paper has also discussed water harvesting technologies that rely on sorbent materials. The primary focus of the paper is to present recent advances in water harvesting systems, such as dehumidifying, condensing, vapor compression refrigeration cycles (VCRCs), thermoelectric coolers (TECs), air conditioning units, fuel cells, and integrated systems. The paper aims to provide a comprehensive understanding of the latest developments in atmospheric water harvesting systems. The paper also presents an assessment of the efficiency and effectiveness of these water harvesting systems. The paper concludes by comparing various approaches to provide accurate descriptive information regarding the amount of water harvested. Additionally, the article proposes suggestions to enhance current water harvesting systems and outlines potential future initiatives. • Water harvesting from fog and dew is a promising source of water. • Sorbent materials have the capacity to absorb moisture and generate water from the atmosphere. • TECs are suitable for collecting atmospheric water across many global regions. • Top water-collecting materials absorb moisture, convert it to water in few in minimal time. • VCRC-based devices offer substantial atmospheric water harvesting potential, analysis shows. [ABSTRACT FROM AUTHOR]

The increasing penetration of intermittent renewable energy sources such as solar and wind is creating new challenges for the stability and reliability of power systems. Electrochemical battery energy storage systems offer a promising solution to these challenges, as they permit to store excess renewable energy and release it when needed. This paper reviews the integration of battery energy storage systems for increasing the penetration of variable sources into power grids. It highlights the impacts of high penetration of intermittent sources on the power system. The paper provides an overview of battery energy storage systems and their characteristics, applications, and technologies suitable for grid-scale use. The article highlighted that lithium and flow batteries are the most widely used technologies. Battery integration to the power grid has the potential to help achieve a penetration rate of 40–50% of variable renewable energies, as this rate may vary depending on the specific characteristics of each electrical system. The paper also proposes an approach to incentivize the use of BESS to increase the share of variable renewable energies in weakly interconnected power grids such as those in Sub-Saharan Africa. • Li-ion, Na–S and VRFB are the most promising technologies for grid applications. • Penetration rates between 40 and 50% of VRE could be achieved with grid-tied batteries. • For power quality applications, ZnBr, VRFB and Li-ion batteries are well-suited. • For power regulation applications, Na–S and Li-ion batteries are well-suited. [ABSTRACT FROM AUTHOR]

In order to mitigate the influence of global warming and greenhouse gasses emission, different proceedings are suggested such as utilizing renewable energies and demand response programs. This paper investigates the expansion of renewable resources and electrical energy storage units in distribution systems towards reducing investment costs and environmental pollution. Since the development of components is not possible in a single-stage due to the limitation of staff and funds, a multi-stage programming is applied to consider various restrictions. According to the penetration of crypto-currency miners in recent years, their impact is evaluated on the problem as the high-rate energy consumers. Moreover, the demand side management strategy and risk-averse scenario-based approach are implemented to analyze the role of responsive loads and model the renewable resources uncertainty, respectively. The results approve that simultaneous expansion of wind turbines, photovoltaics and electrical storage systems decreases the total pollution and cost by 100% and 99.98% after the third year, respectively. The simulations also validate that crypto-currency miners reduce the total revenue by 4.16%, whereas the responsive loads increase it by 9.89%. As well, the fluctuations of wind and solar power decrease the total revenue by 13.27%, in return, the robustness notably improves. [ABSTRACT FROM AUTHOR]

Scientists initiated a pursuit of more resilient and long-lasting energy sources due to the continuous deterioration of the environment and the substantial rise in the expense of conventional energy sources. Solar energy is one of the most cost-effective, environmentally friendly, and easily accessible sustainable energy sources. Photovoltaic/thermal (PV/T) solar modules are gaining popularity due to their ability to utilise more solar radiation to generate electric power and heat gain simultaneously. This study reviews recent advancements in PV/T modules, focusing on the dual conversion of solar radiation into electrical and thermal energy. The review highlights significant improvements, such as the use of nanoparticles, bi-fluid circulation, and innovative cooling techniques. The study examined the main categories of PV/T systems, including air-cooled, water-cooled, bi-fluid-cooled, nano-fluid-cooled, and ternary nanofluid-based units. This paper offers an in-depth analysis of various components within PV/T modules, covering aspects such as concepts, materials, and review techniques. However, challenges remain, including the trade-off between thermal and electrical efficiency and integration into existing infrastructure. Despite these limitations, PV/T systems show great potential for contributing to sustainable energy solutions and achieving global sustainable development goals. Future research directions include integrating an artificially intelligent approach for system optimization and expanding hybrid PV/T technologies. [Display omitted] • A graphical summary of the PV/T types is demonstrated. • Sustainability achievements by the PV/T modules are discussed. • Water, air, nanofluid, and bi-fluid-based coolants are summarised. • Ternary nanofluid-based PV/T is reviewed. [ABSTRACT FROM AUTHOR]

The adoption of renewable energy resources is in the core of energy transition. However, its implementation can be highly impacted by country policies. A limited number of researches investigated solar photovoltaic investments, comparing net-metering rules for distinctive energy consumption levels and different discounted rates, from the investors' point of view. This paper analyzes the impact of Brazilian net-metering rules on solar photovoltaic investments, considering residential scale. The methodology contemplates the development of a Discounted Cash Flow model to calculate Discounted Payback (DP), Net Present Value (NPV), Internal Rate of Return (IRR), and Levelized Cost of Electricity (LCOE) of projects. The case studies consider the impact of Brazilian regulation from net-metering rules (previous, considered, and current), energy consumption levels (Low, Middle, and High), and discount rates (5 %, 10 %, 15 %, and 20 %). The results show that from the previous to current rule the return for investor, on average, decreased 5.77 %. However, this reduction would be of 12.81 % if considered rule was adopted. For the 36 studies carried out, even in the worst case the investments remain viable. Therefore, the existing policy is suitable for the current stage of sector development; minimizing the impacts for energy tariff, distribution companies, consumers, and prosumers. [ABSTRACT FROM AUTHOR]

• Assessing solar power technical potential in China with high-resolution data. • Quantifying the gap between actual generation and technical potential at plant level. • Actual solar power generation is only 30% of the technical potential. • Technology, construction, and management factors cause the underperformance. Improving the power output of solar photovoltaic (PV) farms is critical to maximize the potential of PV power and reduce extensive land use in the context of large-scale deployment of renewable energy. In this paper we developed an integrated solar power potential assessment framework to quantify the gap between technical potential and actual generation of solar PV farms on national, provincial, and plant scales, and identify the key factors that cause the underperformance of PV farms. Specifically, to assess technical potential, hourly meteorological reanalysis data is adopted and the power generation-related parameters are calculated (i.e. optimal panel tilt, array spacing, packing factor etc.) with consideration of their spatial variability. For actual power generation, a detailed plant-level dataset is first established by this study which integrates technical, operational, and geospatial information from 145 solar farms across seven provinces in China. Our results show that the actual PV power generation per square meter is only 1/3 of the estimated technical potential. Technological factor is the primary factor, accounting for 48.43% of the underperformance, followed by engineering and management factors, accounting for 38.55% and 13.02%, respectively. The novelty of our study is revealing the underperformance level of solar farms in reality, identifying the causing factors, and highlighting the importance of integrating land-use efficiency indicators into solar power planning and development. [ABSTRACT FROM AUTHOR]