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[Display omitted] • SAMA, a new open-source microgrid optimization software, was introduced an validated. • Validation compared SAMA's results with industry-standard, Homer Pro proved accuracy. • Results for different locations and climates, confirming SAMA's reliability and accuracy. • SAMA introduces unique emission optimization and top-down pricing methodology for first time. • SAMA is open-source and free, which ensures accessibility and fosters innovation. • SAMA is broadly applicable for renewable, off-grid, grid-tied, and backup power systems. Although there are many software tools for simulations of hybrid energy systems, Homer Pro and Homer Grid are the only tools offering optimal sizing of hybrid energy systems. Originally developed as open-source software, they have been closed, which limits user-developers abilities to adapt and improve the software. In addition, all current proprietary offering suffer from the following limitations: i) high costs that limit accessibility to low-resource labs and individuals, ii) incapable of conducting multi-objective optimization, iii) constrained on any new innovations in hybrid energy system design and operation, iv) difficulties for users to specifically define prices and costs in inputs, v) inability to model different electric utility billing structures, vi) complex pricing methodology, and vii) the absence of machine learning-based predictive modeling. To overcome these limitations, this paper introduces and validates SAMA (Solar Alone Multi-objective Advisor), an open-source microgrid optimization software program designed to optimize hybrid energy system sizes economically using metaheuristic algorithms based on specific load profiles and meteorological data. Through rigorous validation exercises, SAMA's outcomes are compared against those generated by the Homer Pro software across distinct climatic conditions and geographical locations (i.e., Sacramento, California in the marine west coast and New Bern in humid continental climate zones of U.S., respectively). The results demonstrate congruence between SAMA and Homer Pro. SAMA can be used for a diverse array of applications from renewable energy systems to off-grid and grid-tied configurations, and from policy formulation to feasibility assessment. Unique features of SAMA include multi-objective optimizer, levelized emission optimization, different pre-defined utility billing structures, and a top-down pricing methodology. These features further enhance SAMA's adaptability, allowing users to tailor the software to their specific needs and system configurations. Finally, the paper anticipates future advancements that could refine component modeling, accelerate optimization processes, and incorporate advanced data analysis techniques such as machine learning to predict energy demand and production patterns. [ABSTRACT FROM AUTHOR]

[Display omitted] • PCM energy storage and PV/T coupled multi-source heat pump systems were combined. • The thermal performance, energy efficiency, and economy of the system were analyzed. • The performance of paraffin C17 and water as energy storage materials were compared. • The performance of six low-temperature PCMs applied to the system were analyzed. • Compared to the existing system, it saves 56 % of energy and 27.7 % of operating costs. To improve the application of renewable energy in the heating zone, as well as to address the limitations of air and water source heat pump. The study presents a PV/T (photovoltaic/thermal) coupled air–water source heat pump system integrated with phase change energy storage. A theoretical analytical model and TRNSYS simulation model of the system were developed to evaluate the thermal performance, energy efficiency and economics of the system. The performance of phase change energy storage was compared with that of water storage, and the effect of different phase change materials on the system characteristics. The results show that the coupled system achieves a seasonal performance factor of 2.3, a 56 % reduction in energy consumption, and a 27.7 % reduction in operating costs compared to a conventional gas boiler system. Comparative analysis with the water storage system showed that the system equipped with phase change materials performed well in terms of energy consumption, operating costs and heating stability. In addition, the density of the phase change material has a biased effect on the overall performance of the system. This paper can provide a reference value for the study of renewable energy heating systems in cold zone. [ABSTRACT FROM AUTHOR]

District Heating (DH) systems will play an important role in future sustainable energy systems. Existing networks can be optimized by lowering primary return temperatures in order to improve the use of geothermal resources. This can be done by installing triple-pipe systems. This paper defines the concept of triple-pipe configurations as it is understood in France. The objective of this paper is to demonstrate the relevance of those configurations for optimizing geothermal DH system efficiency. A dynamic thermal-hydraulic model was developed using the programming language Modelica. A generic case study is modeled considering the extension of an existing network. It is shown that triple-pipe configurations offer lower return temperatures and gas consumption, while increasing of the renewable energy share in the network energy mix. [ABSTRACT FROM AUTHOR]

• A two-layer framework is proposed for building HVAC and associated multi-energy consumption optimization. • 100% renewable complementarities are proposed for building multi-energy supplies. • A R-C thermodynamic network is formulated to model the building HVAC. • AC slow charging and DC fast charging types of EVs are considered and managed via a novel real-time supply–demand pricing. Building heating, ventilation, and air conditioning (HVAC) and associated energy consumption make up the more and more important part of the world, whose reduction provides a cost-effective path to the "dual carbon" goal. This paper proposes a two-layer management of HVAC-based multi-energy buildings under proactive demand response of fast/slow-charging electric vehicles (EVs). In this paper, the building HVAC is mathematically formulated via a R-C thermodynamic model, which coordinates with multi-energy converters and storages to form a 100% renewable building. The building management is a challenging optimization problem due to its severe constraints and strong spatio-temporal couplings. In the first layer, a day-ahead multi-energy dispatch is formulated to economically optimize the electrical, heat, gas energy carriers. In the second layer, alternating current (AC) slow charging and direct current (DC) fast charging types of EVs are considered and managed via a novel real-time supply–demand pricing mechanism. After acquiring the economical dispatch references in the first layer, the second layer implements a model predictive control (MPC)-based real-time scheduling to handle the multi-energy supply–demand fluctuations. The original two-layer optimization is further handled via mixed-integer linear program (MILP) reformulation for high-efficient solving. Comparisons have shown the advantageous performances of the proposed two-layer optimization over economics and practicability. Simulations results show that the overall system operating cost can be reduced by at most 3.01% with a higher operational flexibility in building management. [ABSTRACT FROM AUTHOR]

In the paper the method for energy and ecological evaluation of refrigeration system based on the adsorption machine is presented. The energy effectiveness is calculated on the level of the primary energy consumption. The method for ecological evaluation is also discussed. In the ecological evaluation the influence on greenhouse gasses (GHG) is taken into account and the ecological effects are expressed as equivalent CO 2 emission. The authors compare the effectiveness of a refrigerator existing in an example Polish food factory supplied with heat from a boiler house fired with natural gas, a cogeneration system and solar collectors. In the last case the climatic conditions and detailed solar radiation data for Poland have been used. The authors demonstrated that the application of cogeneration or renewable energy sources (RES) for the cooling system can lead to energy savings and ecological benefits. To measure the energy effects the authors introduced the following indices: (PES) – Primary Energy Savings and (GHGS) – Greenhouse Gasses Savings. The results of the mentioned indices for different configuration of heating systems are calculated and presented in the paper. [ABSTRACT FROM AUTHOR]

• Battery transport and logistics to increase renewable use and system flexibility. • Full train transport and carpooling to improve the economics of battery use. • Levelized cost of energy of battery transport & logistics is $0.045/kWh averagely. High share of variable renewable energy is challenging to the traditional power system technically and economically. This calls for a significant increase to the system flexibility, which might result in the costs associated with energy storage and costly upgrades to the traditional transmission and distribution system. This paper presents a multi-stage battery transportation and logistics optimization method to increase the renewable energy consumptions, economics, and mobilities of the battery utilization. A new approach is proposed in which the batteries are charged in the renewable power plants and transported back and forth by railways between the renewable power plants and cities. Based on the forecasts of battery supplies/demands, multiple optimization stages (full train transport and carpooling) are designed by the branch-and-bound algorithm and genetic algorithm respectively. The proposed battery transportation and logistics concept and model are performed using the Beijing-Tianjin-Hebei region in China as an example. The results show that the levelized cost of energy of the battery transportation and logistics model is $0.045/kWh averagely. Also, by the use of mobilized batteries, the proposed battery transportation and logistics model increases the system flexibilities and renewable energy deliveries to the end users without the reinforcement of transmission and distribution system and any constraint from a highly penetrated power system. [ABSTRACT FROM AUTHOR]

Highlights • Modeling the variability of the fuel costs over long term. • Modeling the Multi-Source System taking into account changes in fuel costs. • Limiting the number of starts of the diesel generator to increase its lifecycle. • Increasing the fuel cost can lead to an increase of 18% in the design cost. • Optimization algorithm favors the introduction of renewable sources. Abstract Multi-Source Systems combining renewable energy sources with diesel generators have been widely adopted in isolated sites. The economic and ecological aspects are very important for analyzing and evaluating such systems. In this paper, an optimization approach that includes the former aspects has been proposed. This approach takes into account the changes in the fuel cost over a lifecycle and the minimization of the greenhouse gas emission. The proposed method is based on three main steps. At first, a fuel cost progression model over a period of 40 years has been developed. Second, due to the complexity of such systems and in order to simplify the modeling, meta-models have been extracted by using the Design of Experiments technique. Finally, Single-Objective and Multi-Objective Optimization of the system based on economic and ecological criteria have been performed. The obtained results show that, changes in fuel costs have a significant influence on the sizing of the system. Indeed, the increase in fuel cost can lead to an increase of 18% in the design cost. The best solution on Pareto's curve was found with a reduction rate in the fuel consumption between 30 and 35%. Furthermore, the optimization algorithm favors the introduction of renewable sources. [ABSTRACT FROM AUTHOR]

Abstract: This paper studies the feasibility of utilizing photovoltaic systems in a standard residential apartment in Amman city in Jordan. Data on solar radiation, sunshine duration and the ambient temperature has been recorded in Amman city. An apartment in Amman was chosen as a case study to conduct energy and economic calculations. The electrical power needs and cost were calculated for the apartment. The component design and cost of PV system required to supply required energy was calculated and the payback period for the suggested stand-alone PV system in this paper was estimated in a constant inflation rate in electricity price similar to that of interest rate. The calculated payback period was high in a stand-alone system, to decrease payback period a grid-connected PV system is suggested. Considering an annual increase of 3% in electricity price, 15% of payback period was decreased in a stand-alone PV system and 21% in a grid-connected PV system. The output results of this study show that installation of PV system in a residential flat in Jordan may not be economically rewarding owing to the high cost of PV system compared to the cost of grid electricity. A feed-in tariff law of solar electricity may help to reduce PV system cost like the case of Germany. Additional conclusions are PV systems may be economically rewarding in Jordan if applied in locations far from electrical grid or in remote large scale PV power installations to overcome economical limitations of PV technology. [Copyright &y& Elsevier]

In the present paper, an attempt has been made to investigate the theoretical and practical performances of the photovoltaic/thermal (PV/T) system coupled with earth water heat exchanger (EWHE) cooling system for the conditions of semi-arid region of Pilani, Rajasthan. The experimental studies have been performed for different flow rates of cooling water (0.033 kg/s, 0.025 kg/s and 0.017 kg/s) for a typical day climatic conditions. An electrical efficiency comparison was made for two scenarios when the PV panel was connected or disconnected with the thermal collector and found out that the average electrical efficiency of PV/T panels is higher than the normal PV efficiency. The results of the experimental study showed that the maximum PV panel temperature goes up to 73 °C without any cooling. On the other hand, the PV panel temperature drops in the range of 43.68–49.64 °C with the flow rate of 0.033 kg/s. It has been estimated that the electrical and thermal efficiencies of the PV/T system with cooling are in the range of 8.26–8.52% and 44.06–55.45% respectively for flow rate of 0.033 kg/s. The EWHE pipe length of 38 m found to be sufficient for the proposed system. The experimental results are validated with the theoretical model by using basic energy balance equations and found in good agreement with percentage error of 0.91–12.09%. [ABSTRACT FROM AUTHOR]

• Hydrogen storage systems enable flexible energy conversion and scheduling. • Hydrogen storage cost accounts for the largest proportion of system cost. • The hydrogen energy storage system has less demand for energy storage space. With global energy consumption increasing year by year, the industrial sectors of the world's countries have never been more urgent in achieving carbon reduction. Renewable energy plays a crucial role in the industrial decarbonization process. As the most mature renewable energy technology, wind and photovoltaic power generation have made significant progress in recent years. However, the intermittent characteristics hinder the efficient use of renewable energy. Existing research provides sufficient support for the flexible scheduling of large-scale renewable energy. Hence, this paper proposes a combined energy system composed of wind power-photovoltaic-energy storage salt cavern with hydrogen as the energy scheduling carrier. The system mainly realizes energy conversion through electrolytic water equipment and fuel cells. Then, Qianjiang City, Hubei Province, is taken as the analysis object, and the working conditions of each component in the system are optimized with the help of an improved particle swarm optimization algorithm. According to the results, the system's contribution to the energy system is discussed, and the system's economy and carbon reduction effect is studied. The analysis proves that the improved particle swarm optimization algorithm has a stronger solving ability. The combined energy system can effectively improve the economy and renewable energy utilization rate, meet the regional electricity demand, and significantly reduce carbon emissions. The economic analysis of the system shows that the operation and maintenance cost of hydrogen storage salt caverns accounts for the largest proportion of the total cost, about 60 %. Compared with several existing large-scale energy storage technologies, it is found that the energy efficiency of the whole system is only about 40 % due to the limitation of technology maturity. Nevertheless, the flexibility of the hydrogen storage system layout is relatively high. The required underground space volume is only equivalent to 1/6 and 1/2 of pumped storage and compressed air storage with the same scheduling capacity. The system will provide a theoretical support for the optimization of energy pattern and layout. [ABSTRACT FROM AUTHOR]

• Synergistic between renewable energy and cogeneration is an ideal transition path. • Imported and exported power could reduce the CO₂ emissions of the heating system. • Investment costs mainly affect the economy of the future heating systems. • Taken Beijing as a case study, the proposed method can be applied to other regions. In response to climate change, China has set the target to achieve carbon neutrality by 2060. The large-scale development of renewable energy and the decarbonization transition of the heating system are crucial for achieving this target. Is there a synergistic effect between the heating system's decarbonization transition and the use of large-scale renewable energy sources? What effect does this synergistic development have on the CO₂ emissions and the economic costs of an energy system? This paper conducts a case study of Beijing, China, and designs three technical path scenarios for heating system decarbonization transition in the future, namely, business as usual scenario where existing policies and regulations are applied, the electricity substitution scenario where the traditional fossil fuel heating system is replaced by electric heat pump, and the synergistic development scenario where the existing thermal power units are retrofitted to replace the consumption of fossil fuels with renewable energy sources. Using the EnergyPLAN model, the hourly operation of Beijing's power and heating systems under the three scenarios are simulated. The research results are: Firstly, the proportion of local renewable energy will be over 70% in all three scenarios, and in the synergistic development scenario, the electricity and heating demand can be met by 100% renewable energy, reducing CO₂ emissions resulted from fossil fuel combustion; secondly, in view of the real-time match of power supply and demand in the power system, at times renewable energy supply would exceed demand. The rational use of the surplus renewable energy can promote further the synergistic development of decarbonization transition of heating system and renewable energy, reducing the primary energy consumption and CO₂ emissions by over 16% and 28% respectively in the future heating system; Thirdly to improve the economic benefit of a synergistic electric power and heating system, focus should be on the reduction of infrastructure construction cost rather than the reduction of fuel consumption. The proposed method can be extended to regional energy systems with more energy sectors, and can be used to formulate decarbonization transition schemes for industry, agriculture, etc. [ABSTRACT FROM AUTHOR]

[Display omitted] • A comprehensive study on renewable energy resources in North America is conducted. • A detailed evaluation of renewable energy potentials is provided. • Important steps for better use of renewable energy resources are summarized. • Emerging technologies for development and management of renewable energy are addressed. • Theoretical and practical challenges in development of renewable energies are highlighted. Energy is an important drive for the economic development and social growth. The energy demand has remarkably escalated due to the technological developments in various governmental, industrial, and municipal activities. The fast growing rate of the energy demand as well as the fuel prices, along with the necessity to control the greenhouse gas emissions are the leading driving forces for effective exploitation of the renewable energy resources. In fact, satisfying the growing global energy demands and mitigating the climate change are of the utmost importance in the modern days. In this review paper, a detailed overview of the development and evolution of the renewable and sustainable energy sources is provided in terms of their types, characteristics, applications, production processes, advantages and disadvantages. Moreover, we discuss the impacts of the renewable energies on health and environment, along with the relevant policies and regulations. Further, the emerging technologies and theoretical and practical challenges in the development of the renewable energies are analyzed. Particularly, this review provides information on renewable and sustainable energies' status and prospects in North America. Central large-scale technology and distributed configurations of the renewable energies might be improved in the North American countries to effectively utilize the renewable energies for producing electricity, biomass-based fuels, and heating in both local/rural and industrial divisions. In addition to employment opportunities stemmed from manufacturing of the renewable energies, its significant impact on the economic development can be enhanced in the US, Canada, and Mexico through development of the renewable energy sources. [ABSTRACT FROM AUTHOR]

Initially pushed by the European Union (EU) through the Europe 2020 strategy, the development of renewable energies is a strategic action aiming to limit climate changes and cut greenhouse gas emissions. National subsidies favored the diffusion of this new kind of energy sources, even if there are interesting economic opportunities also in non-subsidized markets. Renewable energy (RE) is a sustainable choice, but its management requires a proper analysis, both from political and operational levels. The aim of this paper is the assessment of European renewable energy source (RES) trajectory towards 2020, starting from historical values and through common scientific methods. In addition, a new reference framework is proposed, in order to evaluate RESs performances in Europe. The framework is based on three indicators: (i) share of energy from RESs in gross final energy consumption, (ii) REs primary production per capita and (iii) gross final consumption of REs per capita. Results could have practical implications for the decision makers involved in the management of energy sources throughout Europe and could be used for the comparison on a global scale. [ABSTRACT FROM AUTHOR]

A significant amount of global electric power generation is produced from the combustion of fossil fuels. Steam boilers are one of the most important components for steam and electricity production. The objective of this paper is to establish a theoretical framework for the sustainability analysis of a utility boiler. These analyses can be used by decision-makers to diagnose and optimize the sustainability of a utility boiler. Seven utility boiler systems are analyzed using energy and embodied solar energy (emergy) principles in order to evaluate their environmental efficiencies. They include a subcritical coal fired boiler, a supercritical coal fired boiler, an oil fired boiler, a natural gas fired boiler, a concentrating solar power boiler utilizing a tower configuration, a biomass boiler, and a refuse derived fuel boiler. Their relative environmental impacts were compared. The results show that the natural gas boiler has significantly lower CO 2 emission than an equivalent coal or oil fired boiler. The refuse derived fuel boiler has about the same CO 2 emissions as the natural gas boiler. The emergy sustainability index of a utility boiler system is determined as the measure of its sustainability from an environmental perspective. Our analyses results indicate that the natural gas boiler has a relatively high emergy sustainability index compared to other fossil fuel boilers. Converting existing coal boilers to natural gas boilers is a feasible option to achieve better sustainability. The results also show that the biomass boiler has the best emergy sustainability index and it will remain a means to utilize the renewable energy within the Rankine steam cycle. Before solar boiler technology can be widely used in the United States’ utility power industry, its capital cost and the O&M cost should be reduced. Using the results of this research, decision-makers can make better-informed, environmentally-efficient selections of future utility scale boilers. [ABSTRACT FROM AUTHOR]

With the development of home area network, residents have the opportunity to schedule their power usage in the home by themselves aiming at reducing electricity expenses. Moreover, as renewable energy sources are deployed in home, a home energy management system needs to consider both energy consumption and generation simultaneously to minimize the energy cost. In this paper, a smart home energy management model has been presented in which electrical and thermal appliances are jointly scheduled. The proposed method aims at minimizing the electricity cost of a residential customer by scheduling various type of appliances considering the residents consumption behavior, seasonal probability, social random factor, discomfort index and appliances starting probability functions. In this model, the home central controller receives the electricity price information, environmental factors data as well as the resident desired options in order to optimally schedule appliances including electrical and thermal. The scheduling approach is tested on a typical home including variety of home appliances, a small wind turbine, photovoltaic panel, combined heat and power unit, boiler and electrical and thermal storages over a 24-h period. The results show that the scheduling of different appliances can be reached simultaneously by using the proposed formulation. Moreover, simulation results evidenced that the proposed home energy management model exhibits a lower cost and, therefore, is more economical. [ABSTRACT FROM AUTHOR]

• Urban waterfronts are more suitable for conversion into positive energy districts than residential or more compact urban areas. • A methodology for planning positive energy districts in waterfronts is proposed. • Strategic scenario planning can assist urban planners to choose between scenarios toward positive energy districts in urban waterfronts. • The methodology is validated with a case study in Valencia, Spain. • Scenarios show a common path for a positive energy district in the case study. Cities consume two-thirds of the energy supply, and 70% of carbon dioxide equivalent emissions come from urban environments. Positive Energy Districts are innovative tools to achieve energy and climate neutrality in cities. Positive Energy Districts are regions or neighbourhoods with a positive annual energy balance, obtained mainly through energy efficiency and energy generation from renewables. Urban Waterfronts are extended areas close to the sea, which makes them suitable for several types of production with renewables, therefore seeming to be a suitable location to develop Positive Energy Districts. This paper proposes a method that combines strategic planning for project management and the procedure for energy audits to design the optimal district configuration. The study presents and analyses the case of La Marina de València, a district in a Mediterranean city. Three strategic scenarios, both technically feasible and with a positive energy balance, are presented. All the alternatives include PV and switching to light-emitting diode in lighting. The different strategies presented together with a sensitivity analysis facilitate the decision-making process in energy planning and establish a common pathway to achieve Positive Energy Districts in Urban Water Fronts. The results suggest that urban waterfronts are uniquely suited to achieve a positive annual energy balance, thus emerging as a crucial springboard to provide traction to the positive energy districts policy agenda. [ABSTRACT FROM AUTHOR]

• Novel Dew Point Desalination system based on dew point cooling is introduced. • The system is described with a model based on the convective heat transfer coefficient. • Energy consumption of the system is lower than of the existing desalination methods. • The system operates without an additional heat source. • Applicability of the system in different climates is verified and confirmed. This paper presents the first numerical analysis of a novel Dew Point Desalination unit (DPD), which utilizes the phenomenon of the evaporative cooling process to minimize energy consumption. The proposed solution is based on a modular structure, which allows it to obtain any required water production capacity. The analyses for various operational parameters and various climatic conditions are based on the numerical simulations conducted using a validated mathematical model. The system performance was described with different factors, including specific energy consumption (SEC) and daily water production rate respected to 1 m^3*s^-1 of passing air stream (DWP). It is shown that the DPD system can operate in almost every climate zone, and the desalinated water production consumes less than 1.5 kWh*m^-3 of electric energy It is noted the best performance of the DPD system is achieved in the semi-arid, desert and subtropical climate zones. In these climate zones, the 2-stage DPD system allows the production of desalinated water with an electric energy consumption SEC lower than 0.5 kWh*m^-3. The additional benefit of the DPD system is its modularity. The presented DPD system stands as a module, that can be multiplied as needed to achieve the desired size of the desalination plant. [ABSTRACT FROM AUTHOR]

• The minimum and maximum energy efficiency gains are calculated as 2.8% and 11.9%. • North/south facing modules experienced a 55% increase in exposure to irradiance. • East/west facing modules experienced an increase of 31% exposure to irradiance. • For the wavy water case, maximum increase in irradiance is 49% (N/S) and 33% (E/W). This paper proposes a novel use of bifacial photovoltaic solar panel modules for offshore power production. The proposed bifacial photovoltaic module utilizes the reflected solar irradiance from the water surface. The performance of the system is assessed through simulating a bifacial photovoltaic module mounted on a floater covered with aluminum sheets. The performance of the proposed system is simulated under various operating and design parameters including the location of the sun throughout the day, solar irradiance intensity, as well as wavy and still water conditions and orientation of the module using the COMSOL. It is found that the north/south facing bifacial module experienced a maximum of 55% increase in exposure to irradiance compared to a mono-facial module when operating on the water surface. As for the east/west facing module, it experiences a maximum of 31% exposure to irradiance relative to a mono-facial module. The wavy water simulation yielded similar results, the maximum increase in irradiance exposure is 49% and 33% for the north/south and east/west facing module. Moreover, the energy efficiency of a bifacial module is assessed relative to a mono-facial module. The minimum and maximum energy efficiency gains are calculated as 2.8% and 11.9%, respectively. [ABSTRACT FROM AUTHOR]