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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]

Low or even zero carbon dioxide emissions will be an essential requirement for energy supplies in the near future. Besides transport and electricity generation, industry is another large carbon emitter. Hydrogen produced by renewable energy provides a flexible way of utilizing that energy. Hydrogen, as an energy carrier, could be stored in a large capacity compared to electricity. In Sweden, hydrogen will be used to replace coal for steel production. This paper discusses how the need for electricity to produce hydrogen will affect the electricity supply and power flow in the Swedish power grid, and whether it will result in increased emissions in other regions. Data of the Swedish system will be used to study the feasibility of implementing the hydrogen system from the power system viewpoint, and discuss the electricity price and emission issues caused by the hydrogen production in different scenarios. This paper concludes that the Swedish power grid is feasible for accommodating the additional electricity capacity requirement of producing green hydrogen for the steel industry. The obtained results could be references for decision makers, investors, and power system operators. [ABSTRACT FROM AUTHOR]

To tackle the carbon emission problem, the exploitation of renewable energy resources (RESs) with zero emissions has gained much importance. In this context, hydrogen has become an important resource to involve itself in distributed energy resources (DERs) to generate electricity, energize vehicles, and heat our living areas. The utilization of hydrogen technologies is indispensable due to their procurement, environmental friendliness, and high efficiency for DERs. A challenging area in the field of hydrogen energy technologies is extracting efficient power and integration to DERs. This paper investigates how to model and operate a proton exchange membrane fuel cell (PEMFC) stack in a DER application to establish a living lab facility for educational and research purposes by covering Power-to-X (P2X). The PEMFC model of the studied system is designed in a MATLAB/Simulink environment and implemented in an experimental testbed. Thus, a fuel cell (FC) unit as a complementary source is preferred to be used near a photovoltaic (PV) array, a small-scale wind turbine (WT), and a lead acid battery energy storage system (BESS) by creating a P2X concept to form a living lab platform. Beyond the model, regarding the experimental part, a PV array, a WT, and a BESS are combined with a PEMFC module that is rated output of 1200 W. Expect for all systems, the FC part is emphasized in this study. Also, a dynamic model of the mentioned PEMFC is proposed and verified. • Importance of hydrogen energy is focused on its advantages, future role, potential, and challenges. • FC unit as a complementary source is evaluated by creating a P2X concept. • This platform is designed to meet the energy needs of research-education, diversify the supply, increase energy independence. • Energy procurement is supplied via green energy during a lesson, which is noteworthy and instructive. • Feasibility of combined PV/WT/BESS/PEMFC system is investigated. [ABSTRACT FROM AUTHOR]

With the urgent global need to limit warming to 2 °C as well as a localized need in our case study to address rising energy demand amid electrical and thermal network limitations, a critical examination of demand-side energy reductions and the concept of energy sufficiency is needed. This paper contributes to the sparse literature on bottom-up analysis by utilizing Iceland—a leader in renewable energy generation—as a case study to explore the socio-economic factors influencing energy footprints. Our findings reveal significant energy footprints across various consumption domains, particularly housing and mobility, influenced by income levels, urbanization, and lifestyle choices. The study highlights the paradox of a high renewable energy supply leading to potential misconceptions regarding abundant and low-cost energy, resulting in substantial energy consumption-related environmental impacts. Using detailed household consumption survey data, this research provides insights crucial for developing sustainable energy policies that not only target technological advancements but also address the need for a reduction in energy demand and a shift towards energy sufficiency. This work marks a contribution to the literature through the provision of a case study of low income inequality and high energy footprints in a highly renewable energy system context. Further, this work is useful for Icelandic and international policymakers to understand in such high-demand contexts which consumption domains would be most relevant for sufficiency policies. This comprehensive analysis opens pathways for future research to further explore the intersections of energy consumption, socio-economic factors, and well-being, offering a nuanced understanding necessary for crafting sufficiency and demand-side policies aimed at a sustainable energy future. [ABSTRACT FROM AUTHOR]

Solar energy is one type of clean energy resource, and currently the IMO, EU and UK are targeting net zero carbon emissions by 2050. This paper delves into the integration of photovoltaic (PV) systems into hybrid vessels in order to meet their strategies and targets. The technical challenges that come with designing such systems as well as their economic and environmental impacts are examined. By optimizing the usage of harnessed solar energy, we discover the operational strategy that provides maximal benefits through day-to-day savings as well as over the 25 year lifespan of solar panels. It demonstrates impressive economic viability, with cost savings of up to GBP 4.55 per day and a payoff period as short as 9 years. It also displays a modest emission reduction of up to 8.002 kg of CO2, which serves as proof for a pathway to greener practices in the maritime industry. This report highlights the operational flexibility that a hybrid vessel possesses once paired with a PV system through the ability to withstand regulatory and market changes. Also, when looking ahead, further adoption of PV technology creates opportunities for innovation in adopting renewable energy solutions in maritime transportation. [ABSTRACT FROM AUTHOR]

Renewable energy sources such as wind and solar power exhibit strong stochasticity and volatility, resulting in decreased power supply security and sustainability. A strategically optimized hybrid renewable energy system (HRES) is crucial for maintaining stable load operations and achieving sustainable energy development. This paper introduces an energy optimization management model for an independent HRES consisting of wind turbines, photovoltaic systems, diesel generators, and energy storage units. Operational strategies focus on energy storage-led loads following diesel generator-led load prioritizations. The model aims to optimize objectives to include economic, environmental, and power supply reliability indices. A dynamic adaptive parameter approach balances the parameters of the objective function at various instances. The optimal capacity allocation of the model is solved using the improved gray wolf optimization (IGWO) algorithm. This approach incorporates the golden sine strategy, the levy flight strategy, and the dynamic inverse learning strategy into the traditional GWO algorithm. Analyzing different test functions, evaluation metrics, and actual load data indicates that the proposed algorithm excels in global optimization capabilities and search speeds. The model significantly reduces the economic and environmental costs of the HRES microgrids and improves the sustainable development of renewable energy in various scenarios. [ABSTRACT FROM AUTHOR]

The green transition is a challenge for the Polish economy and energy sector. In this paper, the expert method of analysis was applied and findings revealed that the challenges and prerequisites for an effective transformation of the power sector mainly include technical, technological and organizational issues of energy production and use. The provision of electricity at competitive prices and with a low carbon footprint, for individual consumers and industry, is a prerequisite for maintaining the well-being of the population and ensuring the competitiveness of domestically produced goods. The ambitious climate policy goals of the European Union require immediate action and call for radical changes in the Polish energy sector; in the coming years, it must drastically reduce the amount of energy produced from fossil fuels and replace it with so-called green energy from renewable sources. The main purpose of this article was to highlight the need to modify Poland's energy policy until 2040 in order to make it more consistent with the ambitious climate goals of the European Union. This article also shows that Poland's energy transition must include a shift from fossil fuels to renewables, while ensuring that energy security is stabilized by the current energy and generation resources. To this end, we discuss the issues of creating reserves in the national energy system for the entire period of Poland's energy transition. [ABSTRACT FROM AUTHOR]

The ongoing transition from fossil fuel-based electricity generation toward green energy relying on the intermittent renewable energy sources indispensably requires development of novel energy conversion and storage methods. Depending on a particular location and local resources, pumped storage, lithium- or sodium-ion batteries, compressed air energy storage, as well as the so called power-to-gas (P2G) technologies may be applied. Taking into account the abundant solar energy resources available in the northwestern China, such as Ningxia hui autonomous region, and local water resources coming from the Yellow River, a power-to-hydrogen (P2H2) distributed energy conversion system is proposed in this paper, which is based on a high-efficiency reversible Solid Oxide Cell (rSOC). The conducted studies comprise tests with simulated current based on the actual photovoltaic power station data, and with usage of the as-obtained Yellow River water for the electrolysis mode without any pretreatment. It is documented that the reversible operation is beneficial, and the tested cell can operate for a prolonged time. Of importance, Na, Ca, Mg, and Si elements remain in an evaporator, and do not contaminate the cell, while higher than the initial boron concentration can be found in the condensed exhaust gases. The respective operational parameters of the system correspond to an electrolysis current density loading up 433.3 mA cm−2 for 4 h, as well as fuel cell operation mode with a current density of 8.3 mA cm−2 for 12 h. It is found that the average voltage losses in the electrolysis cell and fuel cell mode are 0.27 %/cycle and 0.886 %/cycle, respectively, indicating that the lifetime of the cells can be more than 800 h. The reported studies demonstrate validity of applying rSOC-based P2H2 system, especially if abundant photovoltaic power and water resources are available. [Display omitted] • The Yellow River water was utilized by rSOC for the first time. • The designed test current was modeled with local photovoltaics. • The P2H2 nearby consumption system can reversibly operate for over 800 h. • The degradation rates in SOFC mode are lower than those in SOEC mode. • The Yellow River water has no significant effect on the degradation rate. [ABSTRACT FROM AUTHOR]

The global energy issue is undergoing transformation owing to various factors, such as climate change and geopolitics. In the long term, the primary pathways to achieve sustainable energy development remain the clean energy and global cooperation. As the largest energy consumption centers, the Asia Pacific and North America possess complementary energy profiles and developmental needs for cooperation. This paper analyses various electricity or hydrogen transmission technologies suitable for the Pacific Rim energy system. The liquid hydrogen superconducting energy pipelines possess the potential to fulfill the demands of long-distance and large-scale energy transmission. Building upon this technology, a super energy pipeline project connecting East Asia and North America across 12 time zones was proposed. It is composed of pipelines and relay energy stations, which can realize large-scale storage and transportation of renewable energy as well as the diversified energy supply at terminals. The techno-economic evaluation of the project has been comprehensively conducted, and the investment can be recovered within 10 years. The project is expected to boost the progress of renewable energy, ensure regional energy security and promote the sustainable development of global energy. [Display omitted] • Proposes cross-continental energy transmission scheme for Pacific Rim. • Highlights the potential of liquid hydrogen superconducting energy pipelines. • Identifies the future requirements for the energy storage and transmission. • Presents a review of the existing global energy mix. [ABSTRACT FROM AUTHOR]

The large-scale centralized development of wind and PV power resources is the key to China's dual carbon targets and clean energy transition. The vast desert–Gobi–wilderness areas in northern and western China will be the best choice for renewable energy development under multiple considerations of resources endowment, land use constraints, technical conditions, and economic level. It is urgent to carry out a quantitative wind and PV resource assessment study in desert–Gobi–wilderness areas. This paper proposed a multi-dimensional assessment method considering the influence of the power grid and transportation infrastructure distributions, which includes three research levels, namely, the technical installed capacity, the development potential, and the development cost. Nine main desert–Gobi–wilderness areas were assessed. The wind and PV technical installed capacities were 0.6 TW and 10.7 TW, and the total development potentials were over 0.12 TW and 1.2 TW, with the full load hours of 2513 and 1759 and the average development costs of 0.28 CNY/kWh and 0.20 CNY/kWh. Finally, this paper proposed the meteorological–electrical division distribution. A case study in the Kubuqi and Qaidam Deserts was carried out on wind–wind and wind–PV collaborative development across different meteorological–electrical divisions, which can reduce by 58% the long-term energy storage capacity and decrease the total system LCOE from 0.488 CNY/kWh to 0.445 CNY/kWh. [ABSTRACT FROM AUTHOR]

• This paper integrates DG sources like PV, WT, FC, MT, BESS in the MG. • A stochastic model of actual data is used to create 4 various case studies for RES. • This paper incorporates utility-driven DSM program in the problem for reducing the operational prices more. • The research does not report on the use of quantum-driven computational intelligence for optimizing energy management in MGs. By integrating renewable energy resources and communication technology into the structure, microgrids (MG) have become self-sustaining with less relying of fossil-fuel based units. In this regard, it is significant to have a highly effective energy management system (EMS) to handle the high volatility of clean energy resources, the uncertainty of time-varying loads, and the fluctuating nature of the market price. Due to the technical limitations, the MG's optimal performance is currently restricted to maximizing operational prices. A study must be conducted to appraise the effects of demand-side management (DSM) on the overall operational costs and peak reductions when integrated with EMS. This study investigates the effect of a utility-driven mutable load shaping method on non-dispatchable energy resources in the renewable microgrids considering the digital twin of solar and wind units. It proposes a three-stage stochastic EMS frame in order to solve the optimal day-ahead planning and to minimize the operating price of network-coupled MG. An initial stage involves creating four potential cases for solar and wind energy production profiles based on real-time meteorological information with the aim o time t , the active power interchange to or from utility for. f minimizing the uncertainty. Stage two involves configuring the MG system, determining the operating limitations, and incorporating DSM load participation information into the objective function. Stage 3 involves designing an optimal power dispatch configuration for DG units, increasing exports to utilities, and comparing the outcomes of each scenario including or excluding DSM involvement. According to the simulation results obtained for the suggested stochastic model implementing 20% DSM, the suggested approach could sucessfuly achieve a price decrease of almost 43.8%. [ABSTRACT FROM AUTHOR]

The use of renewable energy sources is becoming increasingly widespread around the world due to various factors, the most relevant of which is the high environmental friendliness of these types of energy resources. However, the large-scale involvement of green energy leads to the creation of distributed energy networks that combine several different generation methods, each of which has its own specific features, and as a result, the data collection and processing necessary to optimize the operation of such energy systems become more relevant. Development of new technologies for the more optimal use of RES is one of the main tasks of modern research in the field of energy, where an important place is assigned to the use of technologies based on artificial intelligence, allowing researchers to significantly increase the efficiency of the use of all types of RES within energy systems. This paper proposes to consider the methodology of application of modern approaches to the assessment of the amount of energy obtained from renewable energy sources based on artificial intelligence technologies, approaches used for data processing and for optimization of the control processes for operating energy systems with the integration of renewable energy sources. The relevance of the work lies in the formation of a general approach applied to the evaluation of renewable energy sources such as solar and wind energy based on the use of artificial intelligence technologies. As a verification of the approach considered by the authors, a number of models for predicting the amount of solar power generation using photovoltaic panels have been implemented, for which modern machine-learning methods have been used. As a result of testing for quality and accuracy, the best results were obtained using a hybrid forecasting model, which combines the joint use of a random forest model applied at the stage of the normalization of the input data, exponential smoothing model, and LSTM model. [ABSTRACT FROM AUTHOR]

In recent times, the research in sustainable energy resources was integrated with the control approaches of various hybrid renewable energy systems for balancing the electricity generation. The accelerated hybrid energy storage systems and steadily growing energy consumption make the variability and the predictable behavior occur in the renewable energy sources, which requires an energy management system. This paper aims to control hybrid renewable energy systems for power management. The systems consist of photovoltaic (PV) arrays, diesel generators, wind systems with boost converter DC-DC, and inverters. The optimum of the real-time process is less due to prediction errors of multiple renewable sources, which track the output voltage and load current. Model predictive control (MPC) is proposed for problem-solving time operation to address this issue and compensate for the prediction error. The major impact factors, such as optimal split power, stability, reliability of energy, and desired dynamic responses, have been identified by applying the MPC technique. A simulation model has been constructed using MATLAB/Simulink environment to confirm the effectiveness of the MPC technique model. [ABSTRACT FROM AUTHOR]

This paper presents a study that focuses on alleviating the impacts of grid outages in Ethiopia. To deal with grid outages, most industrial customers utilize backup diesel generators (DG) which are environmentally unfriendly and economically not viable. Grid-integration of hybrid renewable energy systems (HRES) might be a possible solution to enhance grid reliability and reduce environmental and economic impacts of utilizing DG. In this study, an optimization of grid integrated HRES is carried out for different dispatch and control strategies. The optimal power supply option is determined by performing comparative analysis of the different configurations of grid integrated HRES. The result of the study shows that grid integrated HRES consisting of photovoltaic and wind turbine as renewable energy sources, and battery and hydrogen as hybrid energy storage systems is found to be the optimal system to supply the load demand. From the hydrogen produced on-site, the FC generator and FCEVs consume 143 620 kg/yr of hydrogen which is equivalent to 394 955 kg/yr gasoline fuel consumption. This corresponds to saving 1 184 865 kg/yr of CO 2 emissions and 605 703 $/yr revenue. Besides, this system yields 547 035.4 $/yr revenue by injecting excess electricity to the grid. The study clearly shows the economic and environmental viability of this new technology for implementation. • Modeling and optimization of grid-integrated HRES including grid-reliability and dispatch control. • Storage of excess electricity produced from renewable energy sources in batteries. • Onsite production of renewable hydrogen with excess electricity produced from renewable energy sources. • The role of renewable hydrogen for simultaneous decarbonization of electricity and transportation sectors. • Minimizing overall operating costs by injecting excess electricity to the grid. [ABSTRACT FROM AUTHOR]

This paper provides a comprehensive overview of the microgrid (MG) concept, including its definitions, challenges, advantages, components, structures, communication systems, and control methods, focusing on low-bandwidth (LB), wireless (WL), and wired control approaches. Generally, an MG is a small-scale power grid comprising local/common loads, energy storage devices, and distributed energy resources (DERs), operating in both islanded and grid-tied modes. MGs are instrumental to current and future electricity network development, such as a smart grid, as they can offer numerous benefits, such as enhanced network stability and reliability, increased efficiency, an increased integration of clean and renewable energies into the system, enhanced power quality, and so forth, to the increasingly growing and complicated power systems. By considering several objectives in both islanded and grid-tied modes, the development of efficient control systems for different kinds of MGs has been investigated in recent years. Among these control methods, LB communication (LBcom)-based control methods have attracted much attention due to their low expenses, recent developments, and high stability. This paper aims to shed some light on different aspects, a literature review, and research gaps of MGs, especially in the field of their control layers, concentrating on LBcom-based control methods. [ABSTRACT FROM AUTHOR]

Considering the difficulty of power supply for automatic observation equipment in the polar regions, this paper introduced a small standalone renewable energy system with wind–solar co-generation as the energy supply scheme. Mathematical models were given, including solar photovoltaic panels, wind turbines, solar irradiance, wind energy density, and renewable energy assessment. ERA-Interim atmospheric reanalysis data were used to evaluate solar energy resources, and the synergistic effect of wind–solar resources on renewable energy was also analyzed and discussed. The system composition of the small standalone renewable energy system was proposed in this study. This system deployed near Zhongshan Station was taken as the object of investigation to analyze the operation performance of each component of the system in different months, and the technical feasibility of the system has also been verified. The results showed that the wind–solar resources in the polar regions had a synergistic effect, which can provide an effective and feasible scheme for the power supply of automatic observation equipment. Through research and analysis, it was found that each component of the renewable energy system, including photovoltaic panels, wind turbines, and batteries, could meet the long-term power supply requirements of automatic observation regardless of the polar periods, polar day or polar night. This paper can not only provide theoretical and data support for the application of small independent renewable energy systems in the polar regions but also provide feasible solutions for clean energy supply of the systems and equipment for independent observation stations deployed in uninhabited islands and alpine regions. [ABSTRACT FROM AUTHOR]

The global renewable energy landscape is changing rapidly. Green energies reduce greenhouse gas emissions, diversify the energy supply, and lower dependence on volatile and uncertain fossil fuel markets. The future looks promising for green energy sources, which are taking on an increasingly important role, especially in the current context, as governments are trying to identify viable solutions to the energy crisis and reduce dependence on fossil fuels. Worldwide, there is a growing interest in and support for green energy sources, a factor that could help accelerate the current energy transition. Despite these positive developments, much remains to be done globally to make the energy transition a reality. In this respect, the European Union member states have committed to a wide neutrality target by establishing an increase in the total share of energy from renewable sources to 55% (by 2030) and, at the same time, reducing the net greenhouse gas effect emissions by at least 55% until 2030 to reach the neutrality target by 2050. Green energy sources are essential for long-term efforts to mitigate climate change and will play an important role in improving energy security and accessibility. The efforts of every country to strengthen the energy sector through the development of green energies will reduce geopolitical risks and disproportionate external costs for society. The large-scale use of green energies will contribute to sustainable development. The objective of our research is to review the literature on green energy in the context of sustainable development by analyzing research conducted by various authors and international organizations on these topics. The period considered for this study is 2011–2020. Our research focused on the EU 27, but the review also took into account the results obtained by other countries worldwide, such as China, the USA, Norway, and Iceland. The main research method used was the analysis of scientific papers, studies developed by international organizations, and a wide set of agreements and political commitments assumed by different states for developing green energy as a solution for sustainable development. The obtained results show an interesting international debate about green energies and how they can contribute to sustainable development. This paper's results also show that in 2019 at the global level, low-carbon energy sources, including nuclear power and renewable energy, accounted for 15.7% of primary energy (solar, wind, hydropower, bioenergy, geothermal and wave and tidal), while in 2021, for the EU 27, the share of energy from renewable sources reached 22%. According to international statistics, more than 90% of the governments of many countries are making investments to efficiently capitalize on green energy sources and to design new models of sustainable economic and social development, in order to lower pollution levels, reduce the dependence on fossil fuel imports and limit the climate change impact. [ABSTRACT FROM AUTHOR]

The energy crisis is affecting a number of countries, but particularly those that are heavily dependent on the traditional energy generation formula (e.g., Poland), as well as those neighbouring the territory of the ongoing war in Ukraine, i.e., Poland, Lithuania, Latvia and Estonia. With this in mind, the authors of this study decided to explore the issue of water energy as a source of green (cheap and environmentally safe) energy in these countries. The main objective of the paper is to review the available literature, which is needed to identify the role hydropower plays in energy security and energy transition in these energy markets. This paper is based on a review and critical appraisal of the available literature and studies together with an inference. The structure of the paper consists of an introduction, the main part of the review and conclusions. The geopolitical location and socio-economic conditions of the adopted set of countries, form the basis of the review of the existing literature on the theme explored and the substantive inference. The main findings of this review indicate that the literature is most strongly focused on the overall assessment of the energy transition of the adopted countries for review, where the hydropower thread is most often taken up as one source of renewable energy supply. Hydropower, due to its relatively low share in the energy systems of the adopted set of countries, is, according to the authors, insufficiently explored. The most significant gap relates to the aspect of the potential for hydropower development in these areas, considering both the construction of new hydropower plants and opportunities signalled in the literature for the modernisation or restoration of existing ones. In this respect, the need for analyses (studies and simulations) of hydropower development, considering the economic benefits associated with their development juxtaposed with the safety dimension of this course of action for the environment (analysis and assessment of environmental costs) is indicated, which is the main recommendation of the review. [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]

Renewable and energy sustainable solutions are the need of the hour in this current era where energy is needed for every single and small task but energy generation resources are limited. The emergence of 6G, IoT (Internet of Things), smart technologies and AI (artificial intelligence) has made it possible to integrate renewable energy solutions to save energy and to preserve green environments by saving energy generation resources. The data are generated from diverse nodes and geographical locations in large amounts, and it is very challenging to manage the transition states of data. Optical fibers and optical channels play an important role in handling the flow of massive data. Innovative solutions are required to handle the transition of data by saving energy optimally. Energy is life, and saving energy is as important as saving life. All the newer technologies are thriving for minimal consumption of energy by exploiting smart solutions and with the advent of renewable solutions for energy generation. In many application scenarios, data must be transmitted to a sink/server within a short span of time as soon as the event takes place. An inter-hop minimal latency is required when data are transferred between hops in a green multi-hop cognitive radio network (GM-CRN), which requires innovative solutions to transmit the data over optical channels by consuming minimal energy. This article focuses on the integration of renewable energy resources in multi-hop optical channels, which not only helps save energy but also optimizes the data transmission rate, throughput and transmission latency. The management of renewable energy generation resources along with inter-hop delay is still a challenging task and this article attempts to provide a solution to address this problem. This paper suggests a mechanism that ensures minimal inter-hop delay and interference avoidance to optimize network utility. The sink allocates licensed channels to the IoT devices with energy harvesting (EH) capability for data transmission by considering the network utility, energy harvesting, and sustainability of energy. The research in this article further investigates a utility optimization and minimal delay problem, which can be decomposed into four deterministic sub-problems, i.e., the device battery management (DBM) problem, data discard control (DDC) problem, sampling rate control (SRC) problem, and interference-free channel allocation (ICA) problem with the aid of Lyapunov Optimization techniques. Finally, an efficient online algorithm is also devised to optimize the network utility by minimal allocation of power to sink nodes without hampering the data transmission speed on optical channels. The results of the proposed mechanism are evaluated by using the standard statistical parameters in a simulated environment, and the proposed mechanism is compared with state-of-the-art techniques to assess the viability of the proposed approach for advanced optical technologies (AOT). [ABSTRACT FROM AUTHOR]

Integrating biomass, photovoltaic, and other renewable energy sources for hydrogen production can form a biomass-photovoltaic-hydrogen integrated energy system (BPH-IES). The system features multi-energy storage and joint supply, as well as cascaded utilization, is a promising co-generation way to meet the system's electricity, heat and hydrogen needs, and has significant energy-exergy-economy-environment (4E) performance. Therefore, scientific and effective evaluation of the BPH-IES is an important prerequisite for promoting its development. Firstly, by analyzing the structure of the BPH-IES system, this paper constructs a comprehensive performance evaluation index system of the system from the 4E dimensions. Secondly, a hybrid multi-criterion decision making (MCDM) framework for the 4E comprehensive performance evaluation of the BPH-IES is constructed, in which the anti-entropy weighting method is used to determine the objective weights, the subjective weights are determined by the decision making trial and evaluation laboratory method improved by intuitionistic fuzzy sets, and the final combined weighting results are obtained based on a game-theoretic method that the objective and subjective weights' heterogeneity can be fully minimized. The grey-relation-analysis-based measurement alternatives and ranking according to the compromise solution method is proposed to determine the ranking of alternatives. This paper selected 8 typical BPH-IES cases for 4E evaluation analysis. The results showed that energy performance is the core dimension that reflects the 4E performance of the system, and system's economy indicators such as energy supply income and energy supply cost will also significantly affect the system's 4E performance. Therefore, the 4E performance of BPH-IES can be effectively improved by expanding the system's demand and supply scale and increasing the system's installed proportion of clean energy and hydrogen penetration. Finally, the ranking consistency test, Leave-One-Out analysis and sample separation test demonstrate that the developed hybrid MCDM can ensure robustness meanwhile improve the decision efficiency. [ABSTRACT FROM AUTHOR]

The objective of the paper is to define long-term factors and trends in the development of the world energy industry and their refraction to Ukrainian realities. The article consists of an introduction, three sections, namely: the main trends in the development of the global fuel and energy complex, analysis of the current state, long-term factors and trends in the development of the national fuel and energy complex of Ukraine. Conclusions end the paper. As for the world energy sector it is shown that its modern changes - Grand Transit - are due to the ideology of sustainable development and have the character of an extraordinary change in the technocenosis, the transition from the use of fossil fuels to energy from renewable sources, mainly - wind and photovoltaic nature. Along with the major tendencies of the Great Transition, there is also the trilemization and politicization of energy sector. Trilemization components are: Energy Security, Energy Equity and Environmental Sustainability. There are three scenarios for the development of the global energy - Unfinished Symphony, Modern Jazz and Hardrock, distinguished by the degree of greening and the availability of energy resources. Political motives are becoming more and more significant at all levels - from global to local. Major players are lobbying their interests, there is an activity of structures from the field of nuclear energy, powerful fuel companies, owners of gas transportation and gas distribution infrastructure. In Ukraine, transformation processes are taking place against the backdrop of low environmental acceptability and high depreciation of fuel and energy sector facilities and infrastructure, political and economic instability. The requirements of decarbonization create challenges to the very existence of coal energy, which is the main component of the energy generating fund of the country and the regions, where mines are located. Options for the development of hydrogen/ammonia energy in the form of vertically integrated energy-chemical systems with the nuclear power plants and reformed coal-fired thermal power plants are considered as promising; energy diversification of mining regions; the creation of virtual power plants based on hydrodynamic water heating installations. [ABSTRACT FROM AUTHOR]

The global trends toward increasing clean and sustainable power generation have brought significant changes and developments in electrical distribution networks. The existing passive networks are being restructured to facilitate renewable distributed generations to ensure high degree of reliability of power supply to customers. A distribution system reliability assessment (DSRA) is crucial to analyze the risk and cost associated with power interruptions and take necessary preventive and corrective actions. This paper presents an approach to DSRA and carries out a comprehensive reliability assessment of an active distribution network (ADN) connected with solar, wind, and tidal energy sources. A multi‐state reliability model is developed, combining the Markov and well‐being frameworks to determine the reliability of a network energized by multiple renewable energy sources (RESs). The load point reliability and worth‐oriented indices, namely SAIDI, SAIFI, CAIDI, AENS, EENS, ECOST and IEAR, are evaluated to analyze the impacts of the three RESs on the reliability of the ADN. The paper also proposes two new metrics to estimate the benefits of adding RESs from the reliability worth and cost perspectives. The analyses have been carried out on the Roy Billinton Test System. The results show that the maximum reliability worth and cost benefits can be extracted from a combined operation of multiple RESs. A combination of solar‐wind‐tidal energy sources, therefore, can be an effective solution for countries having long coastlines to fulfill not only the sustainable energy goals but also to improve the grid's reliability and reduce the monetary losses incurred due to customer interruptions. [ABSTRACT FROM AUTHOR]

Nigeria's power infrastructure is dominated by polluting grid-connected fossil-based power systems. The Nation currently suffers from an acute electricity shortage, making nearly 40% of ongrid customers receive unreliable and inconsistent power below their demand. Solar resources are widespread in the country at considerably good potential than in many European nations. Nevertheless, Nigeria's solar photovoltaic (PV) installation capacity could be better. This paper presents the techno-economic, environmental and risk analysis of a grid-connected 10 kW, 100 kW, and 1 MW PV system for three customer segments in Abuja, Nigeria. It is found that a 1 MW grid-tied PV system is very viable at an electricity export rate not below 0.01 $/kWh and a total initial cost (TIC) of not more than 2000 $/kW for fixed axis system and 2600 $/kWh or lower for the two-axis system. The 10 kW and 100 kW PV systems are only financially viable with fiscal incentives. However, they become profitable with a minimum feed-in tariff of about 0.294, 0.297, 0.223 and 0.214 $/kWh for the fixed 10 kW, 2-axis 10 kW, fixed 100 kW and two-axis 100 kW systems, respectively. [ABSTRACT FROM AUTHOR]

Climate change is one of the global issues being combatted in recent times. One of the measures is a worldwide cutdown on carbon emissions. This has brought about the rapid development of technologies that can best actualise this goal. The decentralised energy system is designed to harness the strengths of small power-generating sources such as renewable energy sources in a noncentralised manner to help meet the global need for clean energy. Renewable energy sources are faced with the challenge of intermittency, which brings about instability in the grid. Another source of clean energy is nuclear energy, which is traditionally large and not flexible; however, the recent development of technology has resulted in a scaled-down version of the large nuclear plants that are more flexible yet provide clean and stable electricity. This paper explores the possibility of deploying nuclear microreactors in the decentralised energy system and describes the features and the challenges of a decentralised energy system. The features of the small modular reactor that make it a viable candidate for the generating source in the decentralised energy system are explored. A case study for a DES system with a microreactor was conducted for a rural area in Nigeria. The HOMER software was used in simulating the optimum system, while TOPSIS was used in ranking the systems. The result showed that the PV/nuclear/battery system ranked first, followed by the PV/nuclear/wind and battery system. [ABSTRACT FROM AUTHOR]

This paper presents a novel approach to designing and optimizing a Solar-Wind Hybrid Energy System (SWHS) for an Electric Vehicle Charging Station (EVCS) and a university shopping complex in India. Objectives include addressing sustainable energy challenges, ensuring reliability, and minimizing the Levelized Power Supply Price (LPSP). Key contributions encompass a two-stage framework for optimal SWHS configuration, consideration of uncertainties in renewable energy generation, and the use of the Ebola Optimization Search Algorithm (ESOA). The first stage models SWHS components, formulates an objective function, and addresses reliability to minimize LPSP. The second stage employs ESOA, inspired by Ebola spread, exploring both local and global search spaces. Simulation results and a load profile analysis validate the proposed framework and ESOA's performance, observing a significant improvement of 15% in LPSP and a 10% increase in system reliability. The study provides insights into optimal Distributed Generation (DG) sizing in SWHS, ensuring reliable and cost-effective power supply for EVCS and commercial applications, contributing to the renewable energy system design and optimization field. The analysis indicates an enhanced system reliability by 10 % and a notable reduction in LPSP by 15 %. [ABSTRACT FROM AUTHOR]

The recent geopolitical conflicts in Europe have underscored the vulnerability of the current energy system to the volatility of energy carrier prices. In the prospect of defining robust energy systems ensuring sustainable energy supply in the future, the imperative of leveraging renewable indigenous energy sources becomes evident. However, as such technologies are integrated into the existing system, it is necessary to shift from the current centralized infrastructure to a decentralized production strategy. This paper presents a method to identify a panel of technological solutions at the district level, intended to reduce complexity for the integration of decentralized models into a national-scale model. The framework's novelty lies in combining a global sensitivity analysis for solution generation with clustering to identify typical configurations. The global sensitivity analysis is performed on a mixed integer linear programming model, which optimally sizes and operates district energy systems. The sensitivity analysis determines the most influential parameters of the model using the Morris method and provides a representative sampling of the solution space by leveraging the Sobol sampling strategy. The latter is then clustered using a density-based algorithm to identify typical solutions. The framework is applied to a suburban and residential Swiss neighborhood. The first outcome of the research is the high sensitivity of the model to energy carrier prices. As a result, Sobol's sampling space separates itself into two system types: those based on a natural gas boiler and those relying on a combination of electrical heaters and heat pumps. For both types, the electricity demand is either fulfilled by PV panels or electricity imports. The identified configurations showcase that the framework successfully generates a panel of solutions composed of various system configurations and operations being representative of the overall solution space. • Energy carriers' retail prices are the most influential parameters of a district energy system. • Energy system configurations differ according to the consumed energy carrier and PV penetration. • PV deployment is affected by electricity tariffs but not by technological implementations. [ABSTRACT FROM AUTHOR]

Biofuels are becoming more important in the renewable energy sources mix. Liquid biofuels are products of agriculture. Bioethanol can be prepared from corn, beetroot and other plants. Biodiesel is mainly made from rapeseed. This paper presents information about biodiesel development in Poland, as well as some background information about its development in the European Union (EU). We analyzed the data about biofuels in the literature, and provide statistical data about liquid biofuel in Poland and other countries of the EU. The aim of the study is to assess the viability of liquid biofuel development in Poland. The base for biodiesel production in Poland and the EU is rapeseed. The production yields and sown area of rapeseed increased in Poland from 2005–2020. This was due to integration and European Union policies which aim to supply clean energy. The energy mix in Poland differs from that of the EU. Solid biofuels have made up the biggest share of renewable energy sources in Poland (73.4%) and the EU (40.1%). Poland has smaller share of wind energy, biogas, heat pump, water energy, solar anergy, municipal waste and geothermal energy in its renewable energy sources compared to the rest of the EU. Only with solid and liquid biofuels is the share of renewable energy sources larger in Poland compared to the EU averages. Poland has decreased its share of solid biofuels and water energy among its renewable energy sources, while other sources have increased. Poland is investing to increase its renewable energy sources. To analyze the opportunities for biodiesel production in Poland, we used the scenario method of analysis. We outlined three scenarios. The first is increasing the production of biodiesel by 3% each year for the next three years. The second is production remains unchanged, i.e., at the 2020 level. The last scenario is decreasing production by 3% each year. According to the first scenario, the total demand for rapeseed for energy and food purposes will be 375 thousand tons in 2025. Such a scenario is very likely to occur because of the growing demand for biodiesel and edible oil. The current situation with Ukraine and the Russian Federation will create an increase in demand for rapeseed, leading to higher prices. [ABSTRACT FROM AUTHOR]

Paper [[3]] focused on mapping the wind potential of the southern coastal areas of Bangladesh to estimate the wind energy potential, along with the reduction in carbon emissions due to wind energy. Thirdly, an optimal dispatching model of IEHS with multiple functional areas considering heat network flow regulation is established to minimize the operation cost of IEHS with multiple functional areas while considering the penalty cost of RES abandonment and the time-of-use electricity price. With its reliable scientific and time-tested wind energy estimation method, this research is very important for the development of wind energy in the southern coastal areas of Bangladesh to meet the increasing energy demands through initiating the development of renewable energy to improve the energy security and reduce the carbon emissions of the country. The authors first summarize the system structure and provide a typical system structure, which includes an energy generation system, an energy distribution system, an energy storage system and energy end users. [Extracted from the article]

Using renewable energy sources instead of fossil fuels is one of the best solutions to overcome greenhouse gas (GHG) emissions. However, in designing clean power generation microgrids, the economic aspects of using renewable energy technologies should be considered. Furthermore, due to the unpredictable nature of renewable energy sources, the reliability of renewable energy microgrids should also be evaluated. Optimized hybrid microgrids based on wind and solar energy can provide cost-effective power generation systems with high reliability. These microgrids can meet the power demands of the consuming units, especially in remote areas. Various techniques have been used to optimize the size of power generation systems based on renewable energy to improve efficiency, maintain reliability, improve the power grid's resilience, and reduce system costs. Each of these techniques has shown its advantages and disadvantages in optimizing the size of hybrid renewable energy systems. To increase the share of renewable energies in electricity supply in the future and develop these new technologies further, this paper reviews the latest and most efficient techniques used to optimize green microgrids from an economical and reliable perspective to achieve a clean, economical, and highly reliable microgrid. [ABSTRACT FROM AUTHOR]

This paper discusses the use of agricultural biomass as a promising resource for renewable energy production, e.g., bio-oil and biogas via pyrolysis and catalysis, among other technologies. In order to prevent the accumulation of agricultural biomass, most countries still use traditional disposal or processing methods, e.g., burning in the field, which not only has a low energy conversion rate, but also releases harmful gases, e.g., CO2, CO, and NH3. These traditional methods are regarded as inefficient with respect to the low utilization of waste; they also pose a threat to human health. The energy conversion of agricultural biomass makes full use of resources and accelerates the development of green energy. In particular, agricultural biomass can lead to the production of high-quality renewable fuels and chemical raw materials through catalytic pyrolysis technologies. The fuel produced using catalytic pyrolysis has a low sulfur and alkali metal contents and techno-economic analysis shows that catalytic pyrolysis greatly reduces the production cost and improves the utilization rate of agricultural biomass. The production of bio-oil and gas via catalytic pyrolysis and agricultural biomass are environmentally friendly and economically feasible for clean energy production. Therefore, additional research is needed to enable the upscaling of renewable energy products. [ABSTRACT FROM AUTHOR]

This paper performs a concept on a new exploration of electricity generation by harvesting the kinetic energy from landing aircraft. Firstly, this paper analyzes and tabulates the current status of renewable energy sources and the conventional power generations in Malaysia's electric supply until 2017. It has been reviewed based on the demand, availability, and power production of the sources. At the same time, the locations and providers for several energy supplies have been identified with the evidence of its rated power being generated. Next, this paper also highlights the plan for achieving a low-carbon country based on the plans which have been in place between 1970 until 2017 in order to create a zero-carbon generation by 2030 for Malaysia's energy sector. Toward the end of this paper, the authors suggest a new method on decarbonization technologies for clean energy in order to reach zero-carbon generation earlier than 2030. It is by introducing a new topology of electrical power generation system using waste energy, which is kinetic energy based on landing aircraft, for the possibility of power generation for a new Malaysia. [ABSTRACT FROM AUTHOR]

Despite a substantial potential of renewable energy sources, the current energy supply system in Iran relies almost entirely on fossil fuel resources. It has imposed significant financial burden on the country and has led to considerable GHG emissions. Moreover, the country is confronting several challenges for harnessing alternative clean energy sources and promoting rational energy policies over the recent decades. To probe the root cause of these problems, this paper first provides an overview on the previous energy planning attempts in Iran. It shows that adequate commitment to a long-term energy planning could have meaningfully prevented these serious challenges. However, the previous studies have had some limitations in terms of employing appropriate planning tools, comprehensive evaluations, and scenarios definition and ranking. This paper thus proposes a power planning framework to assess the sustainability of future electricity scenarios for the period 2015–2050. MESSAGE, a systems engineering optimization model, is employed to evaluate the potential impacts of transitioning to a low-carbon electricity supply system. Using a combined AHP-TOPSIS method, the scenarios are then ranked based on 18 different techno-economic, environmental, and social dimensions of sustainability. The results indicate that scenario Cl_32, in which the share of non-hydro clean energy for electricity generation reaches 32%, is ranked best. • Iran's energy planning studies are reviewed. • A suitable link between energy planning and policy making is necessary for Iran. • A framework for sustainable development of the power sector is proposed. • MCDM is used to assess the sustainability of different scenarios. • The share of non-hydro clean energy technologies should increase up to 32% by 2050. [ABSTRACT FROM AUTHOR]

Renewable energy sources cannot guarantee long-term and stable output supply when they are given energy consumption at the load end. At the same time, traditional solar and utility power supply systems cannot guarantee the priority of using solar energy to generate electricity, which has certain limitations. In this regard, an energy control strategy for achieving smooth and no backflow switching and prioritizing the use of clean energy solar energy under a joint power supply system of a solar power grid and a municipal power grid is proposed, which is used for a conventional combined power supply system of a contactor switching circuit. A topology of low voltage power grid is proposed, which effectively reduces the impact on the solar power grid and the municipal power grid during the system switching process combined control mode for controlling the current phase and repetitive control at the output end of the solar power grid in the combined power supply mode, and adding a feedforward control method for the grid voltage is adopted to ensure that the solar grid and the municipal power prioritize the use of clean energy solar energy and, at the same time, ensure the maximum utilization of solar energy. This paper chose the combined power supply system with the solar power grid and the municipal power grid as the object of this research. The topology structure and controlling strategy of the power supply system were comprehensively and deeply researched, and on this basis, the combined power supply system prototype was designed on the foundation of DSP28335 and CPLD. Moreover, hardware parameters are designed in the system, and an energy management optimization algorithm based on the system is developed on the corresponding experimental platform. The experimental results show that the proposed energy control strategy can effectively reduce the impact on the solar power grid and the municipal power grid during the system switching process, ensure that the solar power grid and the municipal power grid have no backflow combined power supply and give priority to the use of clean energy solar energy. [ABSTRACT FROM AUTHOR]

Summary: With the advent of rapid advancements in the energy storage technologies and in harnessing the renewable resources, a variety of mix of "Problem formulation techniques" and "Solution methodologies" have emerged for scheduling the power generation in Grid integrated environment. Multiple constituent attributes and their combinations thereof define the nature of Unit Commitment problem formulation in a complex way. An attempt has been made in this paper to consolidate the available research efforts, spanning over about past two decades, so as to unravel the rising complexities in developing the unit commitment formulation in this rapidly evolving green energy era. The prevailing unit commitment models have been thoroughly reviewed on the bases of deployment of different combinations of features like objective functions, constraints, optimization techniques, types of renewable generation, and types of storage. This review work presents, in a categorized manner, the viewpoints on problem formulation as well as on the solution methodologies. Further, a novel Unit Commitment model has been proposed by the authors wherein modeling details of each of them have been presented in a conscientious manner. The proposed model is unique as the battery charge/ discharge decision making has been included as a co‐optimization problem with the existing Unit Commitment problem. The superiority of the proposed model has also been reported. [ABSTRACT FROM AUTHOR]

The acceleration of distributed energy resources and carbon pricing policies have compelled utilities to act and to prioritize carbon-constrained infrastructure augmentation in their capital programs. To implement various carbon emission reduction policies, power system transmission planning has become more challenging. The existing energy system will face massive retirement of coal-fired power plants (CFPPs), large scale integration of renewable energy and network expansion. In this paper, an electricity network planning and transformation roadmap, which has two milestones, is put forward. In the first stage, a mathematical model is proposed based on the average cost of carbon emission reduction to realize the cooperation of CFPPs retirement and renewable energy investment. It can help the network carry out the transition from a fossil-fuel dominated system to a low-carbon oriented system. Because of the promising prospect of power-to-gas (P2G) technology, in the second milestone, a method based on carbon emission flow (CEF) is employed to help the power-to-gas stations (P2GSes) to select the construction site and capacity. The gas network constraints are modeled to guarantee that P2GSes can work smoothly without energy flow congestion in both electricity and gas networks. According to the simulation results in case studies, our method can reach the emission reduction target more economically and effectively, and the P2GSes can produce and absorb clean energy. [ABSTRACT FROM AUTHOR]

The increase in energy demand makes it urgent to explore green energy sources. And wind energy is one of the most promising renewable energy sources. In this paper, a rotating hybrid nanogenerator with a combination of a direct-current triboelectric nanogenerator (DC-TENG) and an electromagnetic generator (EMG) is designed; the design concept is to harvest wind energy. First, an optimized ternary DC-TENG is designed based on the ternary dielectric triboelectrification effect. A soft contact structure is designed, which can effectively increase the frictional area as well as reduce the frictional resistance. Then, by introducing the EMG unit, the output power of the device and the speed of charging the capacitor are increased. The high output voltage of the DC-TENG and the high output current of the EMG complement each other to produce excellent power output. At 180 rpm/min, the output power of DC-TENG and EMG can reach 1.78 mW and 215 mW, respectively. With a simple power management circuit design, the device is successfully implemented to power small electronic devices. By charging a suitable capacitor, the device can be used as a power supply to power the sensor. Together with the sensor and power management circuit, it forms a self-powered sensing system that can drive the sensor for continuous operation. This work provides a simple, convenient, and reliable design that offers new insights into energy harvesting in nature. • A ternary dielectric triboelectrification effect triboelectric nanogenerator. • A soft contact structure is designed to minimize frictional resistance. • Introduction of an electromagnetic generator to reduce the capacitor charging time. • Energy supply for the continuous operation of the self-powered sensing systems. [ABSTRACT FROM AUTHOR]

The increasing energy demand in harbour areas, coupled with the need to reduce pollutant emissions, has led to the development of renewable energy-based polygeneration systems to face the carbon footprint of ports and ships at berth. In this way, in the coming years, ports can be converted into modern energy hubs. From this point of view, this paper presents a new dynamic simulation model for assessing and optimizing the energy and economic impact of ports. Here, energy systems and renewable sources can be designed to be connected to national electricity and natural gas grids and can include also alternative fuels (hydrogen, biomethane, etc.) and thermal energy networks, as well as different biomass fluxes (to be exploited for energy aims). Energy availability/demands of near towns and port buildings/infrastructures, as well as on-shore power supply are also included in the dynamic assessments. Hourly weather data and different prices for all the considered energy carriers are taken into account hour by hour. A multi-objective optimization approach is also implemented in the model considering energy and economic indexes to be optimized. The whole model is implemented in a computer tool written in MATLAB. For showing the capability of the developed model, a novel case study referred to the port of Naples (South-Italy) is presented. Here, several renewable energy sources are considered, including an anaerobic biodigester for producing biogas from the organic waste of docked cruise ships. A combined heat and power system (fed by biogas) is implemented in the port energy hub also for supplying absorption chillers. PV panels, and marine power generators are also included. In the conducted analysis, optimization targets are the maximization of system self-consumption and self-sufficiency as well as the minimum simple payback period. The proposed system can effectively contribute to the decarbonization of the port energy demand and reduce harmful pollutant emissions. Results showed that very high rate of renewable energy produced on-site can be exploited (up to 84%) by the considered port facilities, ensuring increasing independency from utility power grid (self-sufficiency index up to 40%). By the obtained results and through the developed simulation/optimization tool, novel design and operating criteria can be achieved for future port energy hubs featured by renewables and bi-directional energy exchange between ships and port. [ABSTRACT FROM AUTHOR]

[Display omitted] • HEH provides new power supply solutions for marine and river monitoring equipment. • Mixed use of PEH and EMH improves prototype output performance. • The use of non-contact magnetism can improve service life. • Prototypes can easily power some commercial sensing electronics. Water contains a great amount of potential energy, out of this, an energy harvesting and converting solution from water is very promising for green renewable energy. In this paper, a hybrid energy harvester (HEH) is proposed, which has a combination of piezoelectric and electromagnetic mechanisms for energy conversion. Two piezoelectric energy harvesters (PEH) and two electromagnetic energy harvesters (EMH) can work synchronously to achieve high-performance output. The structural variables of the prototype are studied and analyzed through the self-designed experimental test system. When the prototype is assembled with optimal structural parameters, the maximum output voltages of a single PEH and EMH are 56.24 V and 1.016 V. The maximum output power of HEH is 22.78mW, which is 21 % higher than that of PEH and 253011 % higher than that of EMH. Subsequent underwater tests and a series of application tests were performed to verify the performance of the HEH, showing that it can easily power some commercially available sensors and small electronic devices. Experimental results show that HEH is promising in wireless self-powering and self-sensing. It provides a new power supply scheme for laying power supply without grid for monitoring equipment in deep sea and ocean environment. [ABSTRACT FROM AUTHOR]

• The study investigates HRES sizes to achieve NZEB status for a hotel building. • An optimization analysis of a hotel's grid-connected HRES is presented. • The PV/wind grid-connected system has the lowest NPC and LCOE. • The electricity price of the proposed HRES, at 2.1 ¢/kWh. • The Egypt's retail electricity prices of 6.9 ¢/kWh. The tourism sector is a key source of national income, and the use of renewable energy resources promotes green and sustainable tourism. In addition, ensuring a reliable supply and efficient use of clean energy is a primary objective of Egypt's Vision 2030, as it has a significant impact on the sustainable development and growth of the tourism sector in Egypt. Net-zero energy buildings (NZEBs) are a promising decarbonization effort as they reduce energy consumption while increasing the share of renewable energy. Therefore, it is worth investigating the opportunities for NZEBs applications in tourism sector. This paper presents an optimization analysis of a hotel's grid-connected hybrid renewable energy system (HRES) based on its technical, economical, and environmental prospects. Seven scenarios are considered for on-site generation to match the energy requirements of the specific hotel building. The proposed hybrid systems incorporate photovoltaic (PV), wind turbine (WT), and biogas generators into a grid-connected system for supplying power to a tourist hotel. The size of the microgrid system is optimized to decrease the net present cost (NPC) and levelized cost of electricity (LCOE). The results reveal that the PV/wind grid-connected system, with renewable energy generators consisting of 143 kW of photovoltaic modules and one 20 kW wind turbine with a hub height of 18 m, has the lowest NPC and LCOE. This hybrid energy system has a net present cost of 388 k$, which is significantly lower compared to the electricity grid's cost of 873 k$. The electricity price of the proposed HRES, at 2.1 ¢/kWh, is highly competitive with Egypt's retail electricity prices of 6.9 ¢/kWh. Moreover, grid-connected HRES can lower the pressure on the electricity grid arising from the feed-in of electricity from HRES. Furthermore, the proposed HRES will help slow climate change by reducing GHG emissions and fossil fuel usage. Finally, this study will provide valuable guidance for the practical application of NZEBs in Egypt as well as similar global zones. [ABSTRACT FROM AUTHOR]

Operation of distributed energy resources and resilience related problems are becoming of most importance in the pursuit for a more sustainable electricity delivery. Microgrids (MGs) could contribute significantly to both issues and may play an important role in the new decentralized paradigm of power systems. This paper proposes a hierarchical organizational scheme of MGs with a clear distinction of the Microgrid, Nanogrid and Picogrid concepts, and addresses a detailed technical literature review to identify and classify MGs main features and design alternatives. Definitions; descriptions of MGs, Nanogrids, Picogrids; operation modes; business models and communication protocols are dispersed in the literature. In order to gather clearly all the existing information, this review has been organized according to four functional layers, inspired by the ones commonly used in Smart Grid architecture description. For each one and whenever possible, the paper classifies the outcomes of the review in a table kind of format that helps summarizing the different MGs׳ options. Regarding the first layer, the paper describes the different physical devices involved in MGs, such as generators, converters, electric vehicles (EV) and energy storage systems (DS) and the DC levels that are being discussed. For the second layer the paper addresses a review of the communication protocols currently used or proposed. Then, the intelligence layer is analyzed concerning any decision making issue related to operation and planning of the MGs as well as any other aspect that may be relevant for taking advantage of MGs potentiality. In the last layer, the paper reviews different business models adapted to a future where MGs will be deployed. Finally, the paper ends with an exhaustive review of the practical MG experiences in place worldwide, classified according to the issues presented previously, and a brief discussion of the key points to be addressed in the MGs deployment. [ABSTRACT FROM AUTHOR]

Security-constrained economic dispatch is executed based on consecutive dispatch intervals in real time. The short-term variations of wind power can cause the system to enter an unsecured operating region inside a dispatch interval, which is referred to as the intra-interval security (IIS) problem in this paper. IIS may not be addressed by existing dispatch methods as the traditional dispatch is to ensure the security at the interval end. This can lead to IIS risks in an interval when a high-wind-penetrated system encounters large intra-interval variations (IIVs) of wind power. To address this issue, an IIS preventive dispatch approach is proposed in this study. This approach models the wind power IIVs and develops a preventive dispatch to ensure the IIS over the interval in terms of line overloads while taking into account the tradeoff between security and economics. The proposed approach is implemented in a linear-programming model whose global optimum can be efficiently obtained by adding Benders-like cuts. Case study on the IEEE 118-bus system proves that a high level of nonlinear IIVs can cause the IIS issue (inside of an interval) even with accurate wind forecasts at both interval ends. The simulations show that some lines can have severe overloads inside the dispatch interval in spite of having flows below their capacity limits at both interval ends, and demonstrate that the proposed approach can mitigate such intra-interval overloads even under the worst case IIV scenario. [ABSTRACT FROM AUTHOR]

Southeast Asia is a significant stakeholder in the global action against climate change, given its growing population, rising greenhouse gas emissions, and vulnerability to climate change impacts. Public policy makers in this region are faced with the challenge of transitioning to cleaner energy sources to enable the attainment of Paris Agreement goals, while also expanding access to affordable and reliable energy supplies. Southeast Asia has one of world's fastest growing rates of greenhouse gas emissions due to rising fossil fuel combustion, second only to South Asia. As such, it is imperative to decouple its energy consumption from emissions growth. This paper reviews Southeast Asia's energy sector trends, with a focus on electricity supply and demand vis-à-vis global decarbonization efforts. Based on global and regional best practices, the paper highlights the crucial role that governments and public policy can play in accelerating the region's clean energy transition, namely through the establishment of mandatory long-term climate and renewable energy targets and binding policies; use of iterative and adaptive power system planning; support for effective market development; financing of pioneering investments and trunk infrastructure; and support for a just and equitable transition. • Countries of Southeast Asia need to accelerate the clean energy transition. • Governments and public policy play a key role in the energy transition. • Policy prescriptions provided based on global and regional best practices. [ABSTRACT FROM AUTHOR]

DC microgrids are becoming integral part of a modern power system due to the growing penetration of DC distributed energy resources and loads, with additional advantages in terms of power quality improvement. They can be used for remote area electrification including villages, mountains, and islands. In this paper, an islanded DC microgrid is considered as a case study for islands with tidal energy potential, which consists of renewable energy resources including solar, wind and tidal, along with Li-ion battery storage. To ensure the efficient operation, an optimal energy management system is proposed for resource scheduling and utilization. In this regard, this paper proposes a two-stage supervisory energy management system for optimal operation of PV/Wind/Tidal microgrid with one-time communication to avoid excessive use of communication bandwidth in real-time. The primary stage schedules the optimal energy share from each energy source thereby enhancing the efficiency of the operation. The secondary stage updates the decision strategies by analyzing aggregated scheduled generation and demand profiles to ensure an effective utilization. The proposed energy management model has been experimentally validated to prove its effectiveness in achieving optimized operation for an islanded DC microgrid. Word Count: 4380 • Off-grid DC microgrid with only green renewable energy sources and battery. • A two-stage (optimization and adjustment stages) energy management system. • The hardware-in-the-loop experimental validation of energy management system. [ABSTRACT FROM AUTHOR]

This paper analyses how 10 localities in the USA and England, recognised as leaders in clean energy and climate action, have used collaborative approaches to develop local climate change plans and energy conservation, efficiency, and renewable energy initiatives. It examines these planning and policy-making processes in the context of Margerum's [2008. A typology of collaboration efforts in environmental management.Environmental Management, 41 (4), 487–500] typology of “action”, “organizational”, and “policy-level” collaborations, as well as Gray's [1989.Collaborating: finding common ground for multiparty problems. San Francisco: Jossey-Bass] classification of collaboration in the “problem-setting”, “direction-setting”, and “implementation” phases. We conducted interviews with local elected officials, municipal staff, energy professionals, and citizen volunteers in each community, supplemented with an analysis of their adopted energy, climate change, and land-use plans. We find that despite the different government structures and political contexts between the two countries, there was a surprising amount of commonality in how the case study localities used collaborative planning to develop local climate plans and clean energy initiatives. These processes were most often initiated by local elected officials and/or high-level staff members, and then carried out in collaboration with local third-sector organisations and other community stakeholders. In the USA, collaboration was strongest at the policy level and in the direction-setting phase, with the distinguishing feature that citizen advisory boards or stakeholder working groups often took a more active role in shaping local plans and policies. The English localities had some of those same types of collaborations, but were more likely to also employ action collaboration, in the implementation phase, in which third-sector organisations coordinated with the locality to directly provide clean energy services. [ABSTRACT FROM AUTHOR]

Promoting electrical transition in vehicle industry has become one of the main objectives for transportation sectors nowadays. However, no consensus has been reached as to whether the penetration of electric vehicles (EVs) have superiority in energy conservation and carbon reduction with life-cycle thinking. Consequently, this paper applies network evolutionary game theory to investigate the evolution trend of industry energy conservation and carbon reduction with promoting electrification in China. To fit the real decision-making environment faced by manufacturers, the greenness competition interactions, competitive strategy invasion, and market uncertainty are further considered under the impact of dual credit policy. Results show that implementing dual credit policy makes electrical transition an irreversible trend for manufacturers, but it does not mean that internal combustion engine vehicle will disappear, rather, it coexists with EVs in a certain proportion, which is negatively related to consumer's acceptance toward EVs. Meanwhile, to address energy conservation and carbon reduction, manufacturers should be encouraged to choose a fuel reduction strategy to decelerate the industry electrification trend, thus acquiring better energy conservation performances. And before increasing consumer's acceptance toward EVs, increasing the proportion of renewable source in primary energy warrants greater urgency and effectiveness to achieve life-cycle emission reduction advantage of EVs. • It is an irreversible trend for all manufacturers to choose electrical transition. • Internal combustion engine vehicles will coexist with electric vehicles eventually. • High invasion ratio of fuel reduction strategy initially is suggested. • Promoting the clean energy supply is of more urgency and effectiveness. • Optimal new energy credit price exists for fuel and carbon reduction objectives. [ABSTRACT FROM AUTHOR]

As a developing nation with its increasing energy demands, Fiji is in the process of introducing renewables to generate green power to minimize its reliance on fossil fuels and to minimize greenhouse emissions. The paper focuses on green power generation with the available renewables. The overview deals with their prospective users and therefore the challenges to those sources within the view of the local context. Photovoltaic standalone systems connect peoples of remote areas with the rest of the country to upgrade their living standard. Power generating authority along with the Ministry of Energy of Fiji are actively involved in evaluating and incorporating these potentials for power generation. Hydropower, bioenergy, solar energy and wind power are the prominent renewables on which Fiji's future power generation would be based. The share of renewable energies in the urban power generation in the calendar year 2019 was about 53% (561.96 million units). 55.9% of the Fijian population lives in rural areas and settlements. The photovoltaic standalone system through the solar home system (SHS) project and mini-hydroelectric-grids have been introduced to electrify these areas. Photovoltaic grid-connected systems are being introduced in the urban population to increase green energy proportion in the country's electricity power generation. Photovoltaic road lights are being planned to replace conventional road lights. The emission of carbon dioxide by the power sector has been gradually reducing since 1993. In 2015, 1925 million metric tonnes of carbon dioxide was emitted which was 21% less than that of 2005. The Government of Fiji is committed to utilize natural renewable energy resources available and generate 99% green electrical power by 2030. This paper sets a benchmark for other pacific island nations in realizing the success that renewables are achieving in the isolated populations of Fiji. • Fiji is blessed with abundant solar energy resources that provide us with the opportunity to explore and utilize renewable energy potentials. The country has a mountainous terrain and powerful rivers that flow from the highlands to the sea making it suitable for the development of Hydro-Electric potential. Electricity Fiji Limited has been working wisely by considering the geographic advantages to produce a liable mix of renewable energy projects across the country, using tailor-suited solutions where they best fit. The analysis of data for different sources of energy demonstrates that the potential renewable resources available to Fiji are hydropower, solar energy (photovoltaic and thermal), bioenergy, wind energy, ocean energy, tidal energy and geothermal energy. The presence of rivers, mountains and data on rainfall make the hydropower the most important source of renewable energy for Fiji • The solar thermal and solar photovoltaic has the potential to be used for water heating, drying crops and fruits (low and medium temperature applications), road and street lighting, off-grid connected PV systems for the scattered and rural population that is far away from the national grid line and photovoltaic power generators of higher rating/capacity to be added with the National grid to reduce the release of CO 2 in the environment using conventional fuels. Fiji Government is seeking to accomplish 99% renewable energy generation by 2030 from a 2013 baseline of 60% and aiming to achieve a 30% reduction in CO 2 emission from the energy sector over the same period. • The Government of Fiji under the Department of Energy's (DOE) Renewable Energy Development Programme (REDP) introduced the use of renewable energy resources for electrification in rural areas. This will reduce Fiji's reliance on imported fossil fuels whilst at the same time improves the livelihood of rural dwellers. • Fiji is located in the active tropical cyclone zone and the cyclone season starts from October and ends in March. The rapid growth in the power generation sector is sometimes adversely affected by these cyclones. Cyclones are accompanied by heavy rain resulting in landslides and can damage the PV standalone generators installed in that vicinity. Such unforeseen disasters not only slow down the preplanned mini-project installation (solar home systems and mini-grids) but also introduce additional liability to replace the damaged PV systems. • The unprecedented weather events, changes in rainfall patterns and temperatures due to climate change enhance the risk for the energy sector in different forms. These risks badly affect economically and as a result delay in the service delivery. This is the main factors delaying to achieve the targeted goals within the specified time. [ABSTRACT FROM AUTHOR]

• A realistic and integrated PSH and CH model is proposed for optimum energy management. • PSH balances energy supply and demand for intermittent renewable energy. • PSH sites with added water streams feeding upper reservoir incur net positive generation. • PSH reduced pumping energy consumption and enhanced off-peak annual energy production. The energy sector contributes to around 60% of total greenhouse gas emissions. To limit climate change, the world is going through an energy transition to clean and affordable energy, therefore the share of variable renewable energy is increasing day by day. Power systems require significant flexibility to operate reliably. Pumped storage hydropower allows load balancing and stable integration of intermittent renewable energy in the electrical grid. All energy storage technologies, including pumped storage hydropower, are considered a net negative contributor to the grid since they draw more energy than they deliver. This paper uniquely investigates the true potential of pumped storage hydropower and its optimum operation along with existing conventional hydropower. It considers power, energy production, and utilization for both installations to determine an equilibrium condition for a net positive energy balance. The case study of the 300 MW Balakot conventional hydropower plant in Khyber Pakhtunkhwa, Pakistan indicates that the pumped storage hydropower sites, where additional water streams reach the upper storage reservoir, can reduce pumping energy consumption by up to 166 GWh/year. Accordingly, a pumped storage hydropower facility is proposed at Paras, Pakistan, modeled, and optimized in an integrated manner with the Balakot conventional hydropower plant for a net positive annual energy generation and profitability. The integrated power and energy modeling and capacity optimization of the hydropower complex highlight the importance of suitable site selection for pumped storage hydropower near existing conventional hydropower reservoirs. Value-added contribution of this configuration is that it can enhance annual energy generation from integrated conventional hydropower, reduce the upfront capital cost of the project by 10–15%, squeeze the project implementation schedule and result in a smaller carbon footprint to meet the ultimate objective of limiting climate change. Additionally, it unlocks huge untapped pumped storage hydropower potential besides existing conventional hydropower. Furthermore, the study guides the scientific and engineering organizations on optimum capacity utilization without impeding energy generation from conventional hydropower facilities. [ABSTRACT FROM AUTHOR]