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This paper navigates the critical role of hydrogen in catalyzing a sustainable energy transformation. This review delves into hydrogen production methodologies, spotlighting green and blue hydrogen as pivotal for future energy systems because of their potential to significantly reduce greenhouse gas emissions. Through a comprehensive literature review and a bibliometric analysis, this study underscores the importance of technological advancements, policy support, and market incentives in promoting hydrogen as a key energy vector. It also explores the necessity of expanding renewable energy sources and international cooperation to secure a sustainable, low-carbon future. The analysis highlights the importance of scalable and cost-effective hydrogen production methods, such as solar-thermochemical and photo-electrochemical processes, and addresses the challenges posed by resource availability and geopolitical factors in establishing a hydrogen economy. This paper serves as a guide for policy and innovation toward achieving global sustainability goals, illustrating the essential role of hydrogen in the energy transition. [ABSTRACT FROM AUTHOR]

In the quest for sustainable and energy-efficient building solutions, the incorporation of phase change materials (PCMs) into building envelopes emerges as a groundbreaking strategy. PCMs, renowned for storing and releasing thermal energy during phase transitions, stand as a promising avenue to curtail energy consumption while enhancing thermal performance. This study rigorously explores the potential energy savings and thermal comfort benefits achievable through PCM integration into building envelopes. Multiple energy simulations are conducted on a residential building model in diverse locations, including Irbid, Amman, and Aqaba in Jordan, and the city of Oradea in Romania, utilizing the EnergyPlus simulation tool embedded in DesignBuilder software v7.0.2.006. The results reveal that BioPCM®, derived from renewable biomass, significantly elevates thermal performance owing to its heightened latent heat of fusion. Optimal outcomes materialize with a PCM melting point of 23 °C, a configuration closer to the interior surface, and a thickness of 37.1 mm. The study underscores the superior performance in moderate climates (Irbid and Amman) compared to hot-dry climates (Aqaba) and cold-wet climates (Oradea, Romania). Financially and environmentally, incorporating PCM in Amman demonstrates potential annual energy savings of 5476.14 kWh, translating to a cost reduction of 1150 USD/year, and a decrease in GHG emissions by 2382.31 kgCO2eq. The estimated payback period for PCM incorporation in external walls is four years, robustly emphasizing the feasibility and multifaceted benefits of this energy-efficient solution. [ABSTRACT FROM AUTHOR]

The energy efficiency of a system and the performance level of its equipment and installations are the two key elements based on which the investment decision in its modernization is made. They are also very important for setting up optimal operation strategies. The energy audit is a well-known and worldwide recognized tool for calculating energy performance indicators and developing improvement measures. This paper is a synthesis of the energy audit results performed for a district heating network that uses geothermal energy as its primary source of energy. The location of the heating system is inside a university campus. The first part explains the necessity of a comprehensive study on district heating networks and introduces the defining elements that characterize the analyzed equipment and installations. The complex energy balance methodology that has been developed and applied to this district heating system is presented in the second part of the paper. Next, the methodology for collecting the input data for the energy and mass balance is explained. In the final part, the numerical values of the performance indicators and the technical measures that must be applied to improve energy efficiency are shown, and conclusions are drawn. [ABSTRACT FROM AUTHOR]

Economic dispatch problem is found in the recent focus of specialists, solving this problem being based especially on metaheuristic algorithms. Social Group Optimization (SGO) is a new metaheuristic algorithm that models human behavior to solve a certain problem, and it has been successfully applied to optimize mathematical functions. This paper investigates the behavior of the SGO algorithm equipped with five chaotic maps (Logistic, Double, Iterative, Singer and Cat), applied to solve the economic dispatch problem with multiple fuel sources. The new algorithm, called Chaotic Social Group Optimization (CSGO), results from including the sequences generated by chaotic maps in the heuristics specific to the SGO algorithm. The performance of the CSGO chaotic algorithm is tested on four systems having various dimensions (10-units, 20-units, 30-units, and 40-units) and characteristics. The SGO and CSGO algorithms are compared with each other and with other algorithms. The obtained results indicate that CSGO algorithms equipped with any of the chaotic maps mentioned has a higher average performance than SGO algorithm. The application of CSGO, compared to SGO, leads to a reduction of the fuel cost between (0.6-6.7) $/h for the analyzed systems. [ABSTRACT FROM AUTHOR]

When hearing about solar energy, most people think about heating their buildings, but only a few are aware of its cooling capacity. Depending of the available amount of radiation, a solar system can stand alone, or have an additional energy source to cover the peak loads. But for times when neither heating, nor cooling are needed, the solar energy may be stored for different periods (from several hours to half a year). After showing the initial status and most recent developments of solar heating and cooling systems, together with possibilities of energy storage for large systems, this paper presents both theoretical and practical approach of a prototype system developed in Greece, by CRES, within HIGH COMBI European project. [ABSTRACT FROM AUTHOR]

Summary: This paper presents a modified whale optimization (MWO) algorithm for solving the problem of parameters estimation for input‐output curves of thermal and hydro generating units that operates in power plants. In order to improve the MWO algorithm, a chaotic component based on logistic map is added. This new algorithm is called chaotic MWO (CMWO). Both MWO and CMWO algorithms have kept the structure of original whale optimization (WO) algorithm, but some characteristics regarding how the solutions positions are updated inside CMWO and MWO phases were modified. Estimation of curve parameters is an optimization problem. Its objective is to minimize the sum of absolute errors between actual values and estimated values. The efficiency of CMWO, MWO, and WO algorithms is tested either on polynomial models or on models that use nonsmooth functions. The results of CMWO algorithm are then compared with the ones obtained by other recently published algorithms. [ABSTRACT FROM AUTHOR]