Applications & Pathways

The maritime industry is under increasing pressure to reduce greenhouse gas emissions especially in countries such as Saudi Arabia that are actively working to transition to cleaner energy. In this paper a new hybrid shipboard power system which incorporates wind turbines solar photovoltaic (PV) panels proton-exchange membrane fuel cells (PEMFCs) and a battery energy storage system (BESS) together for propulsion and hotel load services is proposed. A multi-loop Energy Management System (EMS) based on proportional–integral control (PI) is developed to coordinate the interconnections of the power sources in real time. In contrast to the widely reported model predictive or artificial intelligence optimization schemes the PI-derived EMS achieves similar power stability and hydrogen utilization efficiency with significantly reduced computational overhead and full marine suitability. By taking advantage of the high solar irradiance and coastal wind resources in Saudi Arabia the proposed configuration provides continuous near-zeroemission operation. Simulation results show that the PEMFC accounts for about 90% of the total energy demand the BESS (±0.4 MW 2 MWh) accounts for about 3% and the stationary renewables account for about 7% which reduces the demand for hydro-gas to about 160 kg. The DC-bus voltage is kept within ±5% of its nominal value of 750 V and the battery state of charge (SOC) is kept within 20% to 80%. Sensitivity analyses show that by varying renewable input by ±20% diesel consumption is ±5%. These results demonstrate the system’s ability to meet International Maritime Organization (IMO) emission targets by delivering stable near-zero-emission operation while achieving high hydrogen efficiency and grid stability with minimal computational cost. Consequently the proposed system presents a realistic certifiable and regionally optimized roadmap for next-generation hybrid PEMFC–battery–renewable marine power systems in Saudi Arabian coastal operations.

This paper investigates the performance and economic viability of Combined Cycle Gas Turbines (CCGT) operating on natural gas (NG) and hydrogen within the context of evolving electricity markets. The study is structured into several sections beginning with a benchmark analysis to establish baseline performance metrics including break-even prices and price margins for CCGTs running on NG. The research then explores various base cases and sensitivity analyses focusing on different CCGT capacity factors and the uncertainties surrounding key parameters. The study also compares the performance of CCGTs across different European countries highlighting the impact of increased price fluctuations in forecasted electricity markets. Additionally the paper examines Power-to-X-to-Power (P2X2P) configurations assessing the economic feasibility of hydrogen production and its integration into CCGT operations. The analysis considers scenarios where hydrogen is sourced externally or produced on-site using renewable energy or grid electricity during off-peak hours. The results provide insights into the competitiveness and adaptability of CCGTs in a transitioning energy landscape emphasizing the potential role of hydrogen as a flexible and sustainable energy carrier.

A hybrid energy system (HES) integrates various energy resources to attain synchronized energy output. However HES faces significant challenges due to rising energy consumption the expenses of using multiple sources increased emissions due to non-renewable energy resources etc. This study aims to develop an energy management strategy for distribution grids (DGs) by incorporating a hydrogen storage system (HSS) and demand-side management strategy (DSM) through the design of a multi-objective optimization technique. The primary focus is on optimizing operational costs and reducing pollution. These are approached as minimization problems while also addressing the challenge of achieving a high penetration of renewable energy resources framed as a maximization problem. The third objective function is introduced through the implementation of the demand-side management strategy aiming to minimize the energy gap between initial demand and consumption. This DSM strategy is designed around consumers with three types of loads: sheddable loads non-sheddable loads and shiftable loads. To establish a bidirectional communication link between the grid and consumers by utilizing a distribution grid operator (DGO). Additionally the uncertain behavior of wind solar and demand is modeled using probability distribution functions: Weibull for wind PDF beta for solar and Gaussian PDF for demand. To tackle this tri-objective optimization problem this work proposes a hybrid approach that combines well-known techniques namely the non-dominated sorting genetic algorithm II and multi-objective particle swarm optimization (Hybrid-NSGA-II-MOPSO). Simulation results demonstrate the effectiveness of the proposed model in optimizing the tri-objective problem while considering various constraints.

Marine and island power systems usually incorporate various forms of energy supply which poses challenges to the coordinated control of the system under diverse irregular and complex load operation modes. To improve the stability and self-sufficiency of island-isolated microgrids with high penetration of renewable energy this study proposes a coordinated control strategy for an island microgrid with PV HGT and HESS combining primary power allocation via low-pass filtering with a fuzzy logic-based secondary correction. The fuzzy controller dynamically adjusts power distribution based on the states of charge of the battery and supercapacitor following a set of predefined rules. A comprehensive system model is developed in Matlab R2023b integrating PV generation an electrolyzer HGT and a battery–supercapacitor HESS. Simulation results across four operational cases demonstrate that the proposed strategy reduces DC bus voltage fluctuations to a maximum of 4.71% (compared to 5.63% without correction) with stability improvements between 0.96% and 1.55%. The HESS avoids overcharging and over-discharging by initiating priority charging at low SOC levels thereby extending service life. This work provides a scalable control framework for enhancing the resilience of marine and island microgrids with high renewable energy penetration.

The study focused on designing a sustainable building involving rooftop agrivoltaics advanced glazing technologies and onsite hydrogen production for a residential property in Birmingham UK where green hydrogen produced by harnessing electricity generated by agrivoltaics system on rooftop of the building is employed to change the transparency of vacuum gasochromic glazing and refuel hydrogen-powered fuel cell vehicle using storage hydrogen for a sustainable building approach. The change in the transparency of the glazing reduces the energy requirement of the building according to the occupant’s requirement and weather conditions. This research investigates the performance of various rooftop agrivoltaic systems including vertical optimal 30◦ tilt and dome setups for both monofacial and bifacial agrivoltaic consisting of tomato farming. Promising results were observed for agrivoltaic systems with consistent tomato production of 0.31 kg/m2 with varying shading experienced due to the different photovoltaic setups. Maximum electricity is produced by bifacial 30◦ with 7919 kWh though the lowest LCOE can be observed by monofacial 30◦ with £0.061/kWh. It also compares the efficiency of vacuum gasochromic windows against double glazing vacuum double glazing electrochromic and gasochromic options which can play an essential role in energy saving and reduced carbon emission. Vacuum gasochromic demonstrated the lowest U-value of 1.32 Wm2 K though it has the highest thickness with 24.6 mm. Additionally the study examines the feasibility of small-scale green hydrogen production from the electricity generated by agrivoltaics to fuel hydrogen vehicles and glazing considering the economic viability. The results suggested that the hydrogen required by the glazing accounts for 52.56 g annually and the maximum distance that can be covered theoretically is by bifacial 30◦ which is approximately 64.23 km per day. The interdisciplinary approach aims to optimise land use enhance energy efficiency and promote sustainable urban agriculture to contribute to the UK’s goal of increasing solar energy capacity and achieving net-zero emissions while addressing food security concerns. The findings of this study have potential implications for urban planning renewable energy integration especially solar and sustainable residential design.

The cement industry a foundation of infrastructure development is responsible for nearly 7 % of global CO2 emissions highlighting an urgent need for scalable decarbonization strategies. This study investigates the technoeconomic feasibility of integrating on-site solar-powered green hydrogen production into cement manufacturing processes. A mixed-integer linear programming (MILP) model optimizes the design and operation of solar photovoltaics (PV) proton exchange membrane (PEM) electrolyzer and hydrogen storage for a representative cement plant in Texas. Five hydrogen substitution scenarios (10–30 % of thermal demand) were evaluated based on net present cost (NPC) levelized cost of hydrogen (LCOH) cost of CO2 avoided and greenhouse gas (GHG) emissions reduction. Hydrogen integration up to 30 % is technically viable but economically constrained with LCOH rising non-linearly from $58.7 to $95.3 GJ− 1 due to escalating component costs. Environmentally a 30 % hydrogen share could reduce total U.S. cement sector emissions by 22 %. While significant this confirms at present the solar-driven hydrogen serves as a partial solution rather than a standalone pathway to deep decarbonization suggesting it must complement other strategies like carbon capture electrification and other complementary technologies. The economic viability of this approach is entirely contingent on financial incentives as the investment tax credits of 80 % or higher are essential to enable cost parity with fossil fuels. This work provides a comprehensive techno-economic and environmental framework concluding immense economic barriers and that aggressive policy support is indispensable for enabling the transition to low-carbon cement manufacturing.

Hydrogen fuel cells (HFCs) are an efficient clean energy solution that performs well in backup or remote application but requires an uninterrupted supply of hydrogen. Current manual refueling procedures are laborintensive pose safety risks due to hydrogen’s explosive nature and can lead to power interruption if neglected. An automated system that manages the refueling procedure safely using computer simulations has been designed and demonstrated. The system employs a pressure sensor to monitor hydrogen levels and the microcontroller scans the safety of the environment by sensing leaks and ensuring there is no risk of over-pressure activates an electric solenoid valve when the pressure falls to or below a specified low threshold of 20 bar (P_low). The valve automatically closes when the tank reaches a high-pressure value of 280 bar(P_high) or immediately upon detection of anomalies such as a sensed leak excessive pressure exceeding 320 bar(Pmax_safe) or a prolonged refilling duration beyond 400 seconds. The whole system has been simulated using MATLAB/Simulink executing five distinct test scenarios including normal operation leaks over-pressure and time-out conditions. Simulation results indicate the design is robust with all safety features performing as intended. Furthermore a roadmap for the physical prototyping and testing of the system beginning with inert gases is presented. The automated system has the potential to enhance the ease and safety of operating stationary HFCs.

High-temperature proton exchange membrane fuel cells (HT-PEM FCs) represent a promising avenue for generating carbon dioxide-free electricity through the utilization of hydrogen fuel. These systems present numerous advantages and challenges for mobile applications positioning them as pivotal technologies for the realization of emission-free regional aircraft. Efficient thermal management of such fuel cell-powered systems is crucial for ensuring the safe and durable operation of the aircraft while concurrently optimizing system volume mass and minimizing parasitic energy consumption. This paper presents four distinct heat transfer principles tailored for the FC-system of a conceptual hydrogen-electric regional aircraft exemplified by DLR’s H2ELECTRA. The outlined approaches encompass conductive cooling air cooling liquid cooling phase change cooling and also included is the utilization of liquid hydrogen as a heat sink. Approaches are introduced with schematic cooling architectures followed by a comprehensive evaluation of their feasibility within the proposed drivetrain. Essential criteria pertinent to airborne applications are evaluated to ascertain the efficacy of each thermal management strategy. The following criteria are selected for evaluation: safety ease of integration reliability and life-cycle costs technology readiness and development as well as performance which is comprised of heat transfer weight volume and parasitic power consumption. Of the presented cooling methods two emerged to be functionally suitable for the application in MW-scale aircraft applications at their current state of the art: liquid cooling utilizing water under high pressure or other thermal carrier liquids and phase-change cooling. Air cooling and conductive cooling have a high potential due to their reduced system complexity and mass but additional studies investigating effects at architecture level in large-scale fuel cell stacks are needed to increase performance levels. These potentially suitable heat transfer technologies warrant further investigation to assess their potential for complexity and weight reduction in the aircraft drivetrain.

This report evaluates the role of Hybrid Renewable Energy Systems (HRESs) in supporting South Africa’s energy transition amidst persistent power shortages coal dependency and growing decarbonisation imperatives. Drawing on national policy frameworks including the Integrated Resource Plan (IRP 2019) the Just Energy Transition (JET) strategy and Net Zero 2050 targets this study analyses five major HRES configurations: PV–Battery PV–Diesel–Battery PV–Wind–Battery PV–Hydrogen and Multi-Source EMS. Through technical modelling lifecycle cost estimation and trade-off analysis the report demonstrates how hybrid systems can decentralise energy supply improve grid resilience and align with socio-economic development goals. Geographic application cost-performance metrics and policy alignment are assessed to inform region-specific deployment strategies. Despite enabling technologies and proven field performance the scale-up of HRESs is constrained by financial regulatory and institutional barriers. The report concludes with targeted policy recommendations to support inclusive and regionally adaptive HRES investment in South Africa.

This paper analyzes the potential of hydrogen technologies in transport placing it within the context of global environmental and energy challenges. Its primary purpose is to eval‑ uate the prospects for the implementation of these technologies at international and na‑ tional levels including Poland. This study utilizes a literature review and an analysis of the results of a highly limited exploratory pilot survey measuring public perception of hydrogen technology in transport. It is critical to note that the survey was conducted on a small non‑representative sample and exhibited a strong geographical bias primarily collecting responses from Europe (50 people) and North America (30 people). This study also details hydrogen vehicle types (FCEV HICE) and the essential infrastructure required (HRS). Despite solid technological foundations the development of hydrogen technology heavily relies on non‑technical factors such as infrastructure development support pol‑ icy and social acceptance. Globally the number of vehicles and stations is growing but remains limited with the pace of development correlating with the involvement of coun‑ tries. The pilot survey revealed a generally positive perception of the technology (mainly due to environmental benefits) but highlighted three key barriers: limited availability of refueling infrastructure—51.5% of respondents strongly agreed on this obstacle high pur‑ chase and maintenance costs and insufficient public awareness. Infrastructure subsidies and tax breaks were identified as effective incentives. Hydrogen technology offers a poten‑ tially competitive and sustainable transport solution but it demands significant systemic support intensive investment in large‑scale infrastructure expansion and comprehensive educational activities. Further governmental engagement is crucial. The severe limitations resulting from the pilot nature of the survey should be rigorously taken into account dur‑ ing interpretation.