The negative consequences of toxic emissions from internal combustion engines, energy security, climate change, and energy costs have led to a growing demand for clean power sources in the automotive industry. The development of eco-friendly vehicle technologies, such as electric and hydrogen vehicles, has increased. This article investigates whether hydrogen vehicles will replace electric vehicles in the future. The results showed that fuel-cell cars are unlikely to compete with electric cars. This is due to the advancements in electric vehicles and charging infrastructure, which are becoming more cost-effective and efficient. Additionally, the technical progress in battery electric vehicles (BEVs) is expected to reduce the market share of fuel-cell electric vehicles (FCEVs) in passenger vehicles. However, significant investments have been made in hydrogen cars. Many ongoing investments seem to follow the sunk cost fallacy, where decision-makers continue to invest in an unprofitable project due to their already invested resources. Furthermore, even with megawatt charging, fuel-cell trucks cost more than battery-powered electric trucks. The use cases for fuel-cell electric trucks are also much more limited, as their running expenses are higher compared to electric cars. Hydrogen vehicles may be beneficial for heavy transport in remote areas. However, it remains to be seen if niche markets are large enough to support fuel-cell electric truck commercialization and economies of scale. In summary, we believe that hydrogen vehicles will not replace electric cars and trucks, at least before 2050.

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.

Green hydrogen is becoming an increasingly important energy supply source worldwide. The great potential for the use of hydrogen as a sustainable energy source makes it an attractive energy carrier. In this paper, we discuss the potential of producing green hydrogen in Jordan. Aqaba, located in the south of Jordan, was selected to study the potential for producing green hydrogen, due to its proximity to a water source (i.e., the Red Sea). Two models were created for two electrolyzer types using MATLAB. The investigated electrolyzers were alkaline water (ALK) and polymeric electrolyte membrane (PEM) electrolyzers. The first model was used to compare the required capacity of the PV solar system using ALK and PEM from 2022 to 2025, depending on the learning curves for the development of these technologies. In addition, this model was used to predict the total investment costs for the investigated electrolyzers. Then, a techno-economic model was constructed to predict the feasibility of using this technology, by comparing the use of a PV system and grid electricity as sources for the production of hydrogen. The net present value (NPV) and levelized cost of hydrogen (LCOH) were used as indicators for both models. The environmental effect, according to the reduction of CO₂ emissions, was also taken into account. The annual production of hydrogen was 70.956 million kg. The rate of hydrogen production was 19.3 kg/s and 1783 kg/s for ALK and PEM electrolyzers, respectively. The LCOH was 4.42 USD/kg and 3.13 USD/kg when applying electricity from the grid and generated by the PV system, respectively. The payback period to cover the capital cost of the PV system was 11 years of the project life, with a NPV of USD 441.95 million. Moreover, CO₂ emissions can be reduced by 3042 tons/year by using the PV as a generation source, instead of fossil fuels to generate electricity. The annual savings, with respect to the reduction of CO₂ emissions, was USD 120,135.

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.

Any building’s design should sustain thermal comfort for occupants and promote less energy usage during its lifetime using accurate building retrofits to convert existing buildings into low-energy buildings so that the heating and cooling loads can be minimized. Regarding the methodology adopted in this research, an energy model of an educational building located at the German Jordanian University in Jordan was constructed utilizing DesignBuilder computer software. In addition, it was calibrated utilizing real energy consumption data for a 12-month simulation of energy performance. Subsequently, a computerized evaluation of the roles of building envelope retrofits or the adaptive thermal comfort limits in the reduction of the overall building energy consumption was analyzed. The results of the study show that the current building’s external wall insulation, roof insulation, glazing, windows, and external shading devices are relatively energy-efficient but with high cost, resulting in significant financial losses, even though they achieved noticeable energy savings. For instance, equipping the building’s ventilation system with an economizer culminated in the highest financial profit, contributing to an annual energy savings of 155 MWh. On the other hand, in an occupant-centered approach, applying the adaptive thermal comfort model in wider ranges by adding 1 °C, 2 °C, and 3 °C to the existing operating temperatures would save a significant amount of energy with the least cost (while maintaining indoor thermal comfort), taking over any retrofit option. Using different adaptive thermal comfort scenarios (1 °C, 2 °C, and 3 °C) led to significant savings of around 5%, 12%, and 21%, respectively. However, using different retrofits techniques proved to be costly, with minimum energy savings compared to the adaptive approach.

When they were first conceived, solar cooling systems were designed to be cost-effective and environmentally safe alternatives for the majority of the developing nations that are characterised by their hot climates in contrast with the traditional air conditioning systems powered by electricity that is produced from fossil fuel resources. Nevertheless, developments in photovoltaic (PV) and air-conditioning technologies have impacted on the prospects of solar cooling systems. This study examined two different options: a coupled PV and air conditioner system and a solar cooling system (absorption chillers where thermal energy is provided by solar collectors) for a specific developing country located in the Eastern Mediterranean region whose climate is hot and dry (Jordan). The cooling system comprised a pair of cooled multistage compression, both of which were 700 kW, while the PV system’s size was 2.1 MWp, the utility grid connection was a 0.4 kV 50 Hz net meter (2 m) and it was anticipated that 3300 MWh/year would be generated. The solar cooling system operated at a maximum coefficient of performance (COP) of 0.79 and had an actual recorded COP of 0.32 on the site; when the electricity tariff of $0.1/kWh was considered, the respective levelised cost of energy (LCOE) values were $0.9/kWh and $2.35/kWh respectively. The findings indicate that the initial costs for the solar thermal cooling system and the PV system were approximately $3.150M and $3M, respectively. The current value of future cash payments when discounts of 6% per year were applied to the payments for the combination of PV and air conditioning was about $9,745,000, whereas the solar thermal cooling system will not reach the breakeven point at negative $1,730,000. It is clear the absorption chiller did not display economic feasibility, whereas the value for the coupled PV and air-conditioning systems was under $0.05/kWh. In addition to the extensive maintenance needs, the reduced COP and the practicality and feasibility of the solar thermal cooling systems mean these kinds of technologies are under significant pressure to remain competitive when faced with the development of new air conditioning and PV technologies.