Spain
Hydrogen Consumption and Durability Assessment of Fuel Cell Vehicles in Realistic Driving
Jan 2024
Publication
This study proposes a predictive equivalent consumption minimization strategy (P-ECMS) that utilizes velocity prediction and considers various dynamic constraints to mitigate fuel cell degradation assessed using a dedicated sub-model. The objective is to reduce fuel consumption in real-world conditions without prior knowledge of the driving mission. The P-ECMS incorporates a velocity prediction layer into the Energy Management System. Comparative evaluations with a conventional adaptive-ECMS (A-ECMS) a standard ECMS with a well-tuned constant equivalence factor and a rule-based strategy (RBS) are conducted across two driving cycles and three fuel cell dynamic restrictions (|∕| ≤ 0.1 0.01 and 0.001 A∕cm2 ). The proposed strategy achieves H2 consumption reductions ranging from 1.4% to 3.0% compared to A-ECMS and fuel consumption reductions of up to 6.1% when compared to RBS. Increasing dynamic limitations lead to increased H2 consumption and durability by up to 200% for all tested strategies.
Future of Electric and Hydrogen Cars and Trucks: An Overview
Apr 2023
Publication
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.
Three-dimensional Simulations of Lean H2-air Flames Propagating in a Narrow Gap: n the Validity of the Quasi-two-dimensional Appoximation
Sep 2021
Publication
The premixed propagation of lean isobaric H2-air flames (φ = 0.3) in Hele-Shaw cells (i.e. two parallel plates separated by a small distance h on the order of the thickness of the planar adiabatic flame δf ∼ 3 mm) is investigated numerically. Three-dimensional (3D) simulations with detailed chemistry and transport are used to examine the effect of h on the flame dynamics and its overall normalized propagation speed (S T /S L) for a semi-closed system of size 25δf × 25δf × h. To determine the validity of an existing quasi-two-dimensional (quasi-2D) formulation (derived in the limit of h → 0) to capture the 3D dynamics results for h = 0.1δf h = 0.5δf and h = δf are reported. For h = 0.1δf strong cell splitting/merging is observed with associated low frequency/high amplitude oscillations in the temporal evolution of S T /S L (10-17Hz; 6 ≤ S T /S L ≤ 10). Larger values of h exhibit a much smoother evolution. For h = 0.5δf the cell splitting/merging is milder relaxing to a steady propagating speed of S T /S L ∼ 6 after an initial transient; for h = 1δf the flame dynamics along the h direction starts to play an important role showing two distinct phases: (i) initial symmetric propagation with a linear increase in S T /S L (from 5.3 to 6.8) as early signs of asymmetry are visible (ii) followed by a fully non-symmetric propagation resulting in an abrupt increase in S T /S L that quickly relaxes to a constant value thereafter (S T /S L ∼ 10). Our preliminary results suggest that for the lean H2-air mixture considered the quasi-2D approximation breaks down for h > 0.1δf .
Fuel Cell Hybrid Model for Predicting Hydrogen Inflow through Energy Demand
Nov 2019
Publication
Hydrogen-based energy storage and generation is an increasingly used technology especially in renewable systems because they are non-polluting devices. Fuel cells are complex nonlinear systems so a good model is required to establish efficient control strategies. This paper presents a hybrid model to predict the variation of H2 flow of a hydrogen fuel cell. This model combining clusters’ techniques to get multiple Artificial Neural Networks models whose results are merged by Polynomial Regression algorithms to obtain a more accurate estimate. The model proposed in this article use the power generated by the fuel cell the hydrogen inlet flow and the desired power variation to predict the necessary variation of the hydrogen flow that allows the stack to reach the desired working point. The proposed algorithm has been tested on a real proton exchange membrane fuel cell and the results show a great precision of the model so that it can be very useful to improve the efficiency of the fuel cell system.
Assessment of a Fully Renewable System for the Total Decarbonization of the Economy with Full Demand Coverage on Islands Connected to a Central Grid: The Balearic Case in 2040
Jul 2023
Publication
The transition to clean electricity generation is a crucial focus for achieving the current objectives of economy decarbonization. The Balearic Archipelago faces significant environmental economic and social challenges in shifting from a predominantly fossil fuel-based economy to one based on renewable sources. This study proposes implementing a renewable energy mix and decarbonizing the economy of the Balearic Islands by 2040. The proposed system involves an entirely renewable generation system with interconnections between the four Balearic islands and the Spanish mainland grid via a 650 MW submarine cable. This flexible electrical exchange can cover approximately 35% of the peak demand of 1900 MW. The scenario comprises a 6 GWp solar photovoltaic system a wind system of under 1.2 GWp and a 600 MW biomass system as generation sub-systems. A vanadium redox flow battery sub-system with a storage capacity of approximately 21 GWh and 2.5 GWp power is available to ensure system manageability. This system’s levelized electricity cost (LCOE) is around 13.75 cEUR/kWh. The design also incorporates hydrogen as an alternative for difficult-to-electrify uses achieving effective decarbonization of all final energy uses. A production of slightly over 5 × 104 tH2 per year is required with 1.7 GW of electrolyzer power using excess electricity and water resources. The system enables a significant level of economy decarbonization although it requires substantial investments in both generation sources and storage.
On the Bulk Transport of Green Hydrogen at Sea: Comparison Between Submarine Pipeline and Compressed and Liquefied Transport by Ship
Jan 2023
Publication
This paper compares six (6) alternatives for green hydrogen transport at sea. Two (2) alternatives of liquid hydrogen (LH2) by ship two (2) alternatives of compressed hydrogen (cH2) by ship and two (2) alternatives of hydrogen by pipeline. The ship alternatives study having hydrogen storage media at both end terminals to reduce the ships’ time at port or prescinding of them and reduce the immobilized capital. In the case of the pipeline new models are proposed by considering pressure costs. One scenario considers that there are compression stations every 500 km and the other one considers that there are none along the way. These alternatives are assessed under nine different scenarios that combine three distances: 100 km 2500 km and 5000 km; and three export rates of hydrogen 100 kt/y 1 Mt/y and 10 Mt/y. The results show including uncertainty bands that for the 100 km of distance the best alternative is the pipeline. For 2500 km and 100 kt/y the top alternative is cH2 shipping without storage facilities at the port terminals. For 2500 km and 1 Mt/y and for 5000 km and 100 kt/y the best alternatives are cH2 or LH2 shipping. For the remaining scenarios the best alternative is LH2 shipping.
Levelized Cost of Biohydrogen from Steam Reforming of Biomethane with Carbon Capture and Storage (Golden Hydrogen)—Application to Spain
Feb 2024
Publication
The production of biohydrogen with negative CO2 emissions through the steam methane reforming of biomethane coupled with carbon capture and storage represents a promising technology particularly for industries that are difficult to electrify. In spite of the maturity of this technology which is currently employed in the production of grey and blue hydrogen a detailed cost model that considers the entire supply chain is lacking in the literature. This study addresses this gap by applying correlations derived from actual facilities producing grey and blue hydrogen to calculate the CAPEX while exploring various feedstock combinations for biogas generation to assess the OPEX. The analysis also includes logistic aspects such as decentralised biogas production and the transportation and storage of CO2 . The levelized cost of golden hydrogen is estimated to range from EUR 1.84 to 2.88/kg compared to EUR 1.47/kg for grey hydrogen and EUR 1.93/kg for blue hydrogen assuming a natural gas cost of EUR 25/MWh and excluding the CO2 tax. This range increases to between 3.84 and 2.92 with a natural gas cost of EUR 40/MWh with the inclusion of the CO2 tax. A comparison with conventional green hydrogen is performed highlighting both prices and potential thereby offering valuable information for decision-making.
Towards Suitable Practices for the Integration of Social Life Cycle Assessment into the Ecodesign Framework of Hydrogen-related Products
Feb 2024
Publication
The hydrogen sector is envisaged as one of the key enablers of the energy transition that the European Union is facing to accomplish its decarbonization targets. However regarding the technologies that enable the deployment of a hydrogen economy a growing concern exists about potential burden-shifting across sustainability dimensions. In this sense social life cycle assessment arises as a promising methodology to evaluate the social implications of hydrogen technologies along their supply chains. In the context of the European projects eGHOST and SH2E this study seeks to advance on key methodological aspects of social life cycle assessment when it comes to guiding the ecodesign of two relevant hydrogen-related products: a 5 kW solid oxide electrolysis cell stack for hydrogen production and a 48 kW proton-exchange membrane fuel cell stack for mobility applications. Based on the social life cycle assessment results for both case studies under alternative approaches the definition of a product-specific supply chain making use of appropriate cut-off criteria was found to be the preferable choice when addressing system boundaries definition. Moreover performing calculations according to the activity variable approach was found to provide valuable results in terms of social hotspots identification to support subsequent decision-making processes on ecodesign while the direct calculation approach is foreseen as a complement to ease the interpretation of social scores. It is concluded that advancements in the formalization of such suitable practices could foster the integration of social metrics into the sustainable-by-design framework of hydrogen-related products.
Development of a Fuel Cell-based System for Refrigerated Transport
Nov 2012
Publication
Benchmark refrigerated systems in the road transportation sector are powered by diesel having operation costs of up to 6000 €/y. This paper presents the development of an alternative refrigeration system based on fuel cells with higher efficiency reduced costs and independent of diesel price fluctuations. Energy load profiles have been analyzed and the fuel cell stack and auxiliaries are being modeled in order to dimension and design a balance of plant and control algorithms that ensure a safe and easy utilization. Additionally a prototype shall be tested under different load profiles to validate the control strategies and to characterize the performance of the system.
The Economic Impact and Carbon Footprint Dependence of Energy Management Strategies in Hydrogen-Based Microgrids
Sep 2023
Publication
This paper presents an economic impact analysis and carbon footprint study of a hydrogenbased microgrid. The economic impact is evaluated with respect to investment costs operation and maintenance (O&M) costs as well as savings taking into account two different energy management strategies (EMSs): a hydrogen-based priority strategy and a battery-based priority strategy. The research was carried out in a real microgrid located at the University of Huelva in southwestern Spain. The results (which can be extrapolated to microgrids with a similar architecture) show that although both strategies have the same initial investment costs (EUR 52339.78) at the end of the microgrid lifespan the hydrogen-based strategy requires higher replacement costs (EUR 74177.4 vs. 17537.88) and operation and maintenance costs (EUR 35254.03 vs. 34877.08) however it provides better annual savings (EUR 36753.05 vs. 36282.58) and a lower carbon footprint (98.15% vs. 95.73% CO2 savings) than the battery-based strategy. Furthermore in a scenario where CO2 emission prices are increasing the hydrogen-based strategy will bring even higher annual cost savings in the coming years.
Internal Combustion Engines and Carbon-Neutral Fuels: A Perspective on Emission Neutrality in the European Union
Mar 2024
Publication
Nowadays there is an intense debate in the European Union (EU) regarding the limits to achieve the European Green Deal to make Europe the first climate-neutral continent in the world. In this context there are also different opinions about the role that thermal engines should play. Furhermore there is no clear proposal regarding the possibilities of the use of green hydrogen in the transport decarbonization process even though it should be a key element. Thus there are still no precise guidelines regarding the role of green hydrogen with it being exclusively used as a raw material to produce E-fuels. This review aims to evaluate the possibilities of applying the different alternative technologies available to successfully complete the process already underway to achieve Climate Neutrality by about 2050 depending on the maturity of the technologies currently available and those anticipated to be available in the coming decades.
Green Hydrogen: Resources Consumption, Technological Maturity, and Regulatory Framework
Aug 2023
Publication
Current climate crisis makes the need for reducing carbon emissions more than evident. For this reason renewable energy sources are expected to play a fundamental role. However these sources are not controllable but depend on the weather conditions. Therefore green hydrogen (hydrogen produced from water electrolysis using renewable energies) is emerging as the key energy carrier to solve this problem. Although different properties of hydrogen have been widely studied some key aspects such as the water and energy footprint as well as the technological development and the regulatory framework of green hydrogen in different parts of the world have not been analysed in depth. This work performs a data-driven analysis of these three pillars: water and energy footprint technological maturity and regulatory framework of green hydrogen technology. Results will allow the evaluation of green hydrogen deployment both the current situation and expectations. Regarding the water footprint this is lower than that of other fossil fuels and competitive with other types of hydrogen while the energy footprint is higher than that of other fuels. Additionally results show that technological and regulatory framework for hydrogen is not fully developed and there is a great inequality in green hydrogen legislation in different regions of the world.
Macroeconomic Analysis of a New Green Hydrogen Industry using Input-output Analysis: The Case of Switzerland
Sep 2023
Publication
Hydrogen is receiving increasing attention to decarbonize hard-to-abate sectors such as carbon intensive industries and long-distance transport with the ultimate goal of reducing greenhouse gas (GHG) emissions to net-zero. However limited knowledge exists so far on the socio-economic and environmental impacts for countries moving towards green hydrogen. Here we analyse the macroeconomic impacts both direct and indirect in terms of GDP growth employment generation and GHG emissions of green hydrogen production in Switzerland. The results are first presented in gross terms for the construction and operation of a new green hydrogen industry considering that all the produced hydrogen is allocated to passenger cars (final demand). We find that for each kg of green hydrogen produced the operational phase creates 6.0 5.9 and 9.5 times more GDP employment and GHG emissions respectively compared to the construction phase (all values in gross terms). Additionally the net impacts are calculated by assuming replacement of diesel by green hydrogen as fuel for passenger cars. We find that green hydrogen contributes to a higher GDP and employment compared to diesel while reducing GHG emissions. For instance in all the three cases namely ‘Equal Cost’ ‘Equal Energy’ and ‘Equal Service’ we find that a green hydrogen industry generates around 106% 28% and 45% higher GDP respectively; 163% 43% and 65% more full-time equivalent jobs respectively; and finally 45% 18% and 29% lower GHG emissions respectively compared to diesel and other industries. Finally the methodology developed in this study can be extended to other countries using country-specific data.
Profitability of Hydrogen-Based Microgrids: A Novel Economic Analysis in Terms of Electricity Price and Equipment Costs
Oct 2023
Publication
The current need to reduce carbon emissions makes hydrogen use essential for selfconsumption in microgrids. To make a profitability analysis of a microgrid the influence of equipment costs and the electricity price must be known. This paper studies the cost-effective electricity price (EUR/kWh) for a microgrid located at ‘’La Rábida Campus” (University of Huelva south of Spain) for two different energy-management systems (EMSs): hydrogen-priority strategy and batterypriority strategy. The profitability analysis is based on one hand on the hydrogen-systems’ cost reduction (%) and on the other hand considering renewable energy sources (RESs) and energy storage systems (ESSs) on cost reduction (%). Due to technological advances microgrid-element costs are expected to decrease over time; therefore future profitable electricity prices will be even lower. Results show a cost-effective electricity price ranging from 0.61 EUR/kWh to 0.16 EUR/kWh for hydrogen-priority EMSs and from 0.4 EUR/kWh to 0.17 EUR/kWh for battery-priority EMSs (0 and 100% hydrogen-system cost reduction respectively). These figures still decrease sharply if RES and ESS cost reductions are considered. In the current scenario of uncertainty in electricity prices the microgrid studied may become economically competitive in the near future
Experimental Activities on a Hydrogen-Fueled Spark-Ignition Engine for Light-Duty Applications
Nov 2023
Publication
The increase in the overall global temperature and its subsequent impact on extreme weather events are the most critical consequences of human activity. In this scenario transportation plays a significant role in greenhouse gas (GHG) emissions which are the main drivers of climate change. The decline of non-renewable energy sources coupled with the aim of reducing GHG emissions from fossil fuels has forced a shift towards a net-zero emissions economy. As an example of this transition the European Union has set 2050 as the target for achieving carbon neutrality. Hydrogen (H2 ) is gaining increasing relevance as one of the most promising carbon-free energy vectors. If produced from renewable sources it facilitates the integration of various alternative energy sources for achieving a carbon-neutral economy. Recently interest in its application to the transportation sector has grown including different power plant concepts such as fuel cells or internal combustion engines. Despite exhibiting significant drawbacks such as low density combustion instabilities and incompatibilities with certain materials hydrogen is destined to become one of the future fuels. In this publication experimental activities are reported that were conducted on a sparkignition engine fueled with hydrogen at different operating points. The primary objective of this research is to gain a better understanding of the thermodynamic processes that control combustion and their effects on engine performance and pollutant emissions. The results show the emission levels performance and combustion characteristics under different conditions of dilution load and injection strategy and timing.
Assessment of Selected Alternative Fuels for Spanish Navy Ships According to Multi-Criteria Decision Analysis
Dec 2023
Publication
Climate change and environmental degradation are growing concerns in today’s society which has led to greater awareness and responsibility regarding the need to adopt sustainable practices. The European Union has established the goal of achieving climate neutrality by 2050 which implies a significant reduction in greenhouse gas emissions in all sectors. To achieve this goal renewable energies the circular economy and energy efficiency are being promoted. A major source of emissions is the use of fossil fuels in different types of ships (from transport ships to those used by national navies). Among these it highlights the growing interest of the defense sector in trying to reduce these emissions. The Spanish Ministry of Defense is also involved in this effort and is taking steps to reduce the carbon footprint in military operations and improve sustainability in equipment acquisition and maintenance. The objective of this study is to identify the most promising alternative fuel among those under development for possible implementation on Spanish Navy ships in order to reduce greenhouse gas emissions and improve its capabilities. To achieve this a multi-criteria decision-making method will be used to determine the most viable fuel option. The data provided by the officers of the Spanish Navy is of great importance thanks to their long careers in front of the ships. The analysis revealed that hydrogen was the most suitable fuel with the highest priority ahead of LNG and scored the highest in most of the sections of the officials’ ratings. These fuels are less polluting and would allow a significant reduction in emissions during the navigation of ships. However a further study would also have to be carried out on the costs of adapting to their use and the safety of their use.
Carbon-negative Hydrogen: Exploring the Techno-economic Potential of Biomass Co-gasification with CO2 Capture
Sep 2021
Publication
The hydrogen economy is receiving increasing attention as a complement to electrification in the global energy transition. Clean hydrogen production is often viewed as a competition between natural gas reforming with CO2 capture and electrolysis using renewable electricity. However solid fuel gasification with CO2 capture presents another viable alternative especially when considering the potential of biomass to achieve negative CO2 emissions. This study investigates the techno-economic potential of hydrogen production from large-scale coal/ biomass co-gasification plants with CO2 capture. With a CO2 price of 50 €/ton the benchmark plant using commercially available technologies achieved an attractive hydrogen production cost of 1.78 €/kg with higher CO2 prices leading to considerable cost reductions. Advanced configurations employing hot gas clean-up membrane-assisted water-gas shift and more efficient gasification with slurry vaporization and a chemical quench reduced the hydrogen production cost to 1.50–1.62 €/kg with up to 100% CO2 capture. Without contingencies added to the pre-commercial technologies the lowest cost reduces to 1.43 €/kg. It was also possible to recover waste heat in the form of hot water at 120 ◦C for district heating potentially unlocking further cost reductions to 1.24 €/kg. In conclusion gasification of locally available solid fuels should be seriously considered next to natural gas and electrolysis for supplying the emerging hydrogen economy.
Performance Evaluation of a Fuel Cell mCHP System under Different Configurations of Hydrogen Origin and Heat Recovery
Sep 2023
Publication
Motivated by the growing importance of fuel cell systems as the basis for distributed energy generation systems this work considers a micro-combined heat and power (mCHP) generation system based on a fuel cell integrated to satisfy the (power and thermal) energy demands of a residential application. The main objective of this work is to compare the performance of several CHP configurations with a conventional alternative in terms of primary energy consumption greenhouse gas (GHG) emissions and economic viability. For that a simulation tool has been developed to easily estimate the electrical and thermal energy generated by a hydrogen fuel cell and all associated results related to the hydrogen production alternatives: excess or shortfall of electrical and thermal energy CO2 emission factor overall performance operating costs payback period etc. A feasibility study of different configuration possibilities of the micro-CHP generation system has been carried out considering different heat-to-power ratios (HPRs) in the possible demands and analyzing primary energy savings CO2 emissions savings and operating costs. An extensive parametric study has been performed to analyze the effect of the fuel cell’s electric power and number of annual operation hours as parameters. Finally a study of the influence of the configuration parameters on the final results has been carried out. Results show that in general configurations using hydrogen produced from natural gas save more primary energy than configurations with hydrogen production from electricity. Furthermore it is concluded that the best operating points are those in which the generation system and the demand have similar HPR. It has also been estimated that a reduction in renewable hydrogen price is necessary to make these systems profitable. Finally it has been determined that the most influential parameters on the results are the fuel cell electrical efficiencies hydrogen production efficiency and hydrogen cost.
Environmental and Material Criticality Assessment of Hydrogen Production via Anion Exchange Membrane Electrolysis
Oct 2023
Publication
The need to drastically reduce greenhouse gas emissions is driving the development of existing and new technologies to produce and use hydrogen. Anion exchange membrane electrolysis is one of these rapidly developing technologies and presents promising characteristics for efficient hydrogen production. However the environmental performance and the material criticality of anion exchange membrane electrolysis must be assessed. In this work prospective life cycle assessment and criticality assessment are applied first to identify environmental and material criticality hotspots within the production of anion exchange membrane electrolysis units and second to benchmark hydrogen production against proton exchange membrane electrolysis. From an environmental point of view the catalyst spraying process heavily dominates the ozone depletion impact category while the production of the membrane represents a hotspot in terms of the photochemical ozone formation potential. For the other categories the environmental impacts are distributed across different components. The comparison of hydrogen production via anion exchange membrane electrolysis and proton exchange membrane electrolysis shows that both technologies involve a similar life-cycle environmental profile due to similar efficiencies and the leading role of electricity generation for the operation of electrolysis. Despite the fact that for proton exchange membrane electrolysis much less material is required due to a higher lifetime anion exchange membrane electrolysis shows significantly lower raw material criticality since it does not rely on platinum-group metals. Overall a promising environmental and material criticality performance of anion exchange membrane electrolysis for hydrogen production is concluded subject to the expected technical progress for this technology.
Green Fleet: A Prototype Biogas and Hydrogen Refueling Management System for Private Fleet Stations
Aug 2023
Publication
Biogas and hydrogen (H2 ) are breaking through as alternative energy sources in road transport specifically for heavy-duty vehicles. Until a public network of service stations is deployed for such vehicles the owners of large fleets will need to build and manage their own refueling facilities. Fleet refueling management and remote monitoring at these sites will become key business needs. This article describes the construction of a prototype system capable of solving those needs. During the design and development process of the prototype the standard industry protocols involved in these installations have been considered and the latest expertise in information technology systems has been applied. This prototype has been essential to determine the Strengths Challenges Opportunities and Risks (SCOR) of such a system which is the first step of a more ambitious project. A second stage will involve setting up a pilot study and developing a commercial system that can be widely installed to provide a real solution for the industry.
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