Applications & Pathways

Mitigating anthropogenic climate change and achieving the Paris climate goals is one of the greatest challenges of the twenty-first century. To meet the Paris climate goals sector-specific transformation pathways need to be defined. The different transformation pathways are used to hypothetically quantify whether a defined climate target is achievable or not. For this reason a bottom-up model was developed to assess the extent of selected industrial decarbonization options compared to conventionally used technologies from an emissions perspective. Thereby the bottom-up model is used to analyze the German container and flat glass industries as an example. The results show that no transformation pathway can be compatible with the 1.5 °C based strict carbon dioxide budget target. Even the best case scenario exceeds the 1.5 °C based target by approximately +200%. The 2 °C based loose carbon dioxide budget target is only achievable via fuel switching the complete phase-out from natural gas to renewable energy carriers. Furthermore the results of hydrogen for flat glass production demonstrate that missing investments in renewable energy carriers may lead to the non-compliance with actually achievable 2 °C based carbon dioxide budget targets. In conclusion the phase-out from natural gas to renewable energies should be executed at the end of the life of any existing furnace and process emissions should be avoided in the long term to contribute to 1.5 °C based strict carbon dioxide budget target.

In this paper the optimal and safe operation of a hybrid power system based on a fuel cell system and renewable energy sources is analyzed. The needed DC power resulting from the power flow balance on the DC bus is ensured by the FC system via the air regulator or the fuel regulator controlled by the power-tracking control reference or both regulators using a switched mode of the above-mentioned reference. The optimal operation of a fuel cell system is ensured by a search for the maximum of multicriteria-based optimization functions focused on fuel economy under perturbation such as variable renewable energy and dynamic load on the DC bus. Two search controllers based on the global extremum seeking scheme are involved in this search via the remaining fueling regulator and the boost DC–DC converter. Thus the fuel economy strategies based on the control of the air regulator and the fuel regulator respectively on the control of both fueling regulators are analyzed in this study. The fuel savings compared to fuel consumed using the static feed-forward control are 6.63% 4.36% and 13.72% respectively under dynamic load but without renewable power. With renewable power the needed fuel cell power on the DC bus is lower so the fuel cell system operates more efficiently. These percentages are increased to 7.28% 4.94% and 14.97%.

Hydrogen fuel has shown promise as a clean alternative fuel aiding in the reduction of fossil fuel dependence within the transportation sector. However hydrogen refueling stations and infrastructure remains a barrier and are a prerequisite for consumer adoption of low-cost and low-emission fuel cell electric vehicles (FCEVs). The costs for FCEV fueling include both station capital costs and operation and maintenance (O&M) costs. Contributing to these O&M costs unscheduled maintenance is presently more costly and more frequent than for similar gasoline fueling infrastructure and is asserted to be a limiting factor in achieving FCEV customer acceptance and cost parity. Unscheduled maintenance leads to longer station downtime therefore causing an increase in missed fueling opportunities which forces customers to seek refueling at other operable stations that may be significantly farther away. This research proposes a framework for a hydrogen station prognostics health monitoring (H2S PHM) model that can minimize unexpected downtime by predicting the remaining useful life for primary hydrogen station components within the major station subsystems. The H2S PHM model is a data-driven statistical model based on O&M data collected from 34 retail hydrogen stations located in the U.S. The primary subcomponents studied are the dispenser compressor and chiller. The remaining useful life calculations are used to decide whether or not maintenance should be completed based on the prediction and expected future station use. This paper presents the background method and results for the H2S PHM model as for a means for improving station availability and customer confidence in FCEVs and hydrogen infrastructure

A regional integrated energy system (RIES) synergizing multiple energy forms is pivotal for enhancing renewable energy use and mitigating the greenhouse effect. Considering that the equipment of the current regional comprehensive energy system is relatively simple there is a coupling relationship linking power generation refrigeration and heating in the cogeneration system which is complex and cannot directly meet various load demands. This article proposes a RIES optimization model for bottom-source heat pumps and hydrogen storage systems in the context of comprehensive demand response. First P2G electric hydrogen production technology was introduced into RIES to give full play to the high efficiency advantages of hydrogen energy storage system and the adjustable thermoelectric ratio of the HFC was considered. The HFC could adjust its own thermoelectric ratio according to the system load and unit output. Second through the groundsource heat pump’s cleaning efficiency function further separation and cooling could be achieved. The heat and electrical output of RIES improved the operating efficiency of the system. Thirdly a comprehensive demand response model for heating cooling and electricity was established to enable users to reasonably adjust their own energy use strategies to promote the rational distribution of energy in the system. The model integrates power-to-gas (P2G) technology leveraging the tunable thermoelectric ratio of a hydrogen fuel cell (HFC) to optimize the generation of electricity and heat while maximizing the efficiency of the hydrogen storage system. Empirical analysis substantiated the proposed RIES model’s effectiveness and economic benefits when integrating ground-source HP and electric hydrogen production with IDR. Compared with the original model the daily operating cost of the proposed model was reduced by RMB 1884.16.

Hydrogen mobility is a powerful strategy to fight climate change promoting the decarbonization of the transportation sector. However the higher flammability of hydrogen in comparison with traditional fuels raises issues concerning the safety of hydrogen-powered vehicles in particular when urban mobility in crowded areas is concerned. In the present study a comparative analysis of alternative hydrogen storage concepts for buses is carried out. A specific inherent safety assessment methodology providing a hazard footprint of alternative hydrogen storage technologies was developed. The approach provides a set of ex-ante safety performance indicators and integrates a sensitivity analysis performed by a Monte Carlo method. Integral models for consequence analysis and a set of baseline frequencies are used to provide a preliminary identification of the worstcase credible fire and explosion scenarios and to rank the inherent safety of alternative concepts. Cryocompressed storage in the supercritical phase resulted as the more hazardous storage concept while cryogenic storage in the liquid phase at ambient pressure scored the highest safety performance. The results obtained support risk-informed decision-making in the shift towards the promotion of sustainable mobility in urban areas.

The aim of this paper is the design and implementation of an advanced model predictive control (MPC) strategy for the management of a wind–solar microgrid (MG) both in the islanded and grid-connected modes. The MG includes energy storage systems (ESSs) and interacts with external hydrogen and electricity consumers as an extra feature. The system participates in two different electricity markets i.e. the daily and real-time markets characterized by different time-scales. Thus a high-layer control (HLC) and a low-layer control (LLC) are developed for the daily market and the real-time market respectively. The sporadic characteristics of renewable energy sources and the variations in load demand are also briefly discussed by proposing a controller based on the stochastic MPC approach. Numerical simulations with real wind and solar generation profiles and spot prices show that the proposed controller optimally manages the ESSs even when there is a deviation between the predicted scenario determined at the HLC and the real-time one managed by the LLC. Finally the strategy is tested on a lab-scale MG set up at Khalifa University Abu Dhabi UAE.

Increasingly stringent sustainability and decarbonization objectives drive investments in adopting environmentally friendly low and zero-carbon fuels. This study presents a comparative framework of green hydrogen green ammonia and green methanol production and application in a clear context. By harnessing publicly available data sources including from the literature this research delves into the evaluation of green fuels. Building on these insights this study outlines the production process application and strategic pathways to transition into a greener economy by 2050. This envisioned transformation unfolds in three progressive steps: the utilization of green hydrogen green ammonia and green methanol as a sustainable fuel source for transport applications; the integration of these green fuels in industries; and the establishment of mechanisms for achieving the net zero. However this research also reveals the formidable challenges of producing green hydrogen green ammonia and green methanol. These challenges encompass technological intricacies economic barriers societal considerations and far-reaching policy implications necessitating collaborative efforts and innovative solutions to successfully develop and deploy green hydrogen green ammonia and green methanol. The findings unequivocally demonstrate that renewable energy sources play a pivotal role in enabling the production of these green fuels positioning the global transition in the landscape of sustainable energy.

Distributed waste-to-hydrogen (WtH) systems are a potential solution to tackle the dual challenges of sustainable waste management and zero emission transport. Here we propose a concept of distributed WtH systems based on gasification and fermentation to support hydrogen fuel cell buses in Glasgow. A variety of WtH scenarios were configured based on biomass waste feedstock hydrogen production reactors and upstream and downstream system components. A cost-benefit analysis (CBA) was conducted to compare the economic feasibility of the different WtH systems with that of the conventional steam methane reforming-based method. This required the curation of a database that included inter alia direct cost data on construction maintenance operations infrastructure and storage along with indirect cost data comprising environmental impacts and externalities cost of pollution carbon taxes and subsidies. The levelized cost of hydrogen (LCoH) was calculated to be 2.22 GB P/kg for municipal solid waste gasification and 2.02 GB P/kg for waste wood gasification. The LCoHs for dark fermentation and combined dark and photo fermentation systems were calculated to be 2.15 GB P/kg and 2.29 GB P/kg. Sensitivity analysis was conducted to identify the most significant influential factors of distributed WtH systems. It was indicated that hydrogen production rates and CAPEX had the largest impact for the biochemical and thermochemical technologies respectively. Limitations including high capital expenditure will require cost reduction through technical advancements and carbon tax on conventional hydrogen production methods to improve the outlook for WtH development.

Clean hydrogen is a key pillar for the net zero economy which can be deployed by consistent utilization on heavy-duty transport. This study investigates a distributed green hydrogen infrastructure (DHI) for heavy-duty transportation consisting of on-site hydrogen production storage compression and refueling systems in Italy. Two options for energy supply are analyzed: grid connection using green energy via Power Purchasing Agreements (PPAs) and direct connection to the photovoltaic field respectively. Radiation data are representative of the three main Italian areas namely South (Catania) Center (Roma) and North (Milano). The sensitivity analysis varies the PPA value between 50 V/MWh and 200 V/MWh and the water electrolysis capacity factor between 20% and 100%. The study finds that the LCOH ranges from 7.4 V/kgH2 to 67.8 V/kgH2 for the first option and 5.5 V/kgH2 to 27.5 V/kgH2 for the second option with Southern Italy having the lowest LCOH due to higher solar irradiation. The research shows that a DHI can offer economic and technical benefits for heavy-duty mobility. However the performance is highly influenced by external conditions such as hydrogen demand and electricity prices. This study provides valuable insights into designing and operating a DHI for heavy-duty mobility promoting a carbon-free society.

In this research we developed a hydrogen (H2 ) electric generator in an H2 generation system based on chemical reactions. In the experiment we tested the performance of the H2 electric generator and measured the amount of H2 generated. The maximum output was 700 W and the thermal efficiency was 18.2%. The theoretical value and measured value were almost the same and the maximum error was 4%.