Spain
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.
Phasing Out Steam Methane Reformers with Water Electrolysis in Producing Renewable Hydrogen and Ammonia: A Case Study Based on the Spanish Energy Markets
Jul 2023
Publication
Deploying renewable hydrogen presents a significant challenge in accessing off-takers who are willing to make long-term investments. To address this challenge current projects focus on large-scale deployment to replace the demand for non-renewable hydrogen particularly in ammonia synthesis for fertiliser production plants. The traditional process involving Steam Methane Reformers (SMR) connected to Haber-Bosch synthesis could potentially transition towards decarbonisation by gradually integrating water electrolysis. However the coexistence of these processes poses limitations in accommodating the integration of renewable hydrogen thereby creating operational challenges for industrial hubs. To tackle this issue this paper proposes an optimal dispatch model for producing green hydrogen and ammonia while considering the coexistence of different processes. Furthermore the objective is to analyse external factors that could determine the appropriate regulatory and pricing framework to facilitate the phase-out of SMR in favour of renewable hydrogen production. The paper presents a case study based in Spain utilising data from 2018 2022 and 2030 perspectives on the country's renewable resources gas and electricity wholesale markets pricing ranges and regulatory constraints to validate the model. The findings indicate that carbon emissions taxation and the availability and pricing of Power Purchase Agreements (PPAs) will play crucial roles in this transition - the carbon emission price required for total phasing out SMR with water electrolysis would be around 550 EUR/ton CO2.
Hydrogen Production from Methanol–Water Solution and Pure Water Electrolysis Using Nanocomposite Perfluorinated Sulfocationic Membranes Modified by Polyaniline
Oct 2022
Publication
In this work we report the preparation of Nafion membranes containing two different nanocomposite MF-4SC membranes modified with polyaniline (PANI) by the casting method through two different polyaniline infiltration procedures. These membranes were evaluated as a polymer electrolyte membrane for water electrolysis. Operating conditions were optimized in terms of current density stability and methanol concentration. A study was made on the effects on the cell performance of various parameters such as methanol concentration water and cell voltage. The energy required for pure water electrolysis was analyzed at different temperatures for the different membranes. Our experiments showed that PEM electrolyzers provide hydrogen production of 30 mL/min working at 160 mA/cm2 . Our composite PANI membranes showed an improved behavior over pristine perfluorinated sulfocationic membranes (around 20% reduction in specific energy). Methanol–water electrolysis required considerably less (around 65%) electrical power than water electrolysis. The results provided the main characteristics of aqueous methanol electrolysis in which the power consumption is 2.34 kW h/kg of hydrogen at current densities higher than 0.5 A/cm2 . This value is ~20-fold times lower than the electrical energy required to produce 1 kg of hydrogen by water electrolysis.
Modelling and Operation Strategy Approaches for On-site Hydrogen Refuelling Stations
Aug 2023
Publication
The number of Fuel Cell Electric Vehicles (FCEVs) in circulation has undergone a significant increase in recent years. This trend is foreseen to be stronger in the near future. In correlation with the FCEVs market increase the hydrogen delivery infrastructure must be developed. With this aim many countries have announced ambitious projects. For example Spain has the objective of increasing the number of Hydrogen Refuelling Stations (HRS) with public access from three units in operation currently to about 150 by 2030. HRSs are complex systems with high variability in terms of layout design size of components operational strategy hydrogen generation method or hydrogen generation location. This paper is focused on on-site HRS with electrolysis-based hydrogen production which provides interesting advantages when renewable energy is utilized compared to off-site hydrogen production despite their complexity. To optimize HRS design and operation a simulation model must be implemented. This paper describes a generic on-site HRS with electrolysis-based hydrogen production a cascaded multi-tank storage system with multiple compressors renewable energy sources and multiple types of dispensing formats. A modelling approach of the layout is presented and tested with real-based parameters of an HRS currently under development which is capable of producing 11.34 kg/h of green H2 with irradiation at 1000 W/m2. For the operation an operational strategy is proposed. The modelled system is tested through several simulations. A sensitivity analysis of the effects of hydrogen demand and day-ahead hydrogen production objective on emissions demand satisfaction and variable costs is performed. Simulation results show how the operational strategy has achieved service up to 310 FCEVs refuelling events of heavy duty and light duty FCEVs bringing the total H2 sold up to almost 7200 H2kg in one month of winter. Additionally considering variable costs of the energy from the utility grid the model shows a profit in the range of 21–50 k€ for a daily demand of 60 H2kg/day and 100 H2kg/day respectively. In terms of emissions a year simulation with 60 H2kg/day of demand shows specific emissions in the production of H2 in Spain of 6.26 kgCO2eq/H2kg which represents a greenhouse gas emission intensity of 52.26 kgCO2eq/H2MJ.
The Role of Hydrogen-based Power Systems in the Energy Transition of the Residential Sector
Sep 2021
Publication
The unsustainable and continuous growth of anthropogenic emissions of greenhouse gases (GHG) has pushed governments private companies and stakeholders to adopt measures and policies to fight against climate change. Within this framework increasing the contribution of renewable energy sources (RES) to final consumed energy plays a key role in the planned energy transition. Regarding the residential sector in Europe 92% of GHG emissions comes from 75% of the building stock that is over 25 years old and highly inefficient. Thus this sector must raise RES penetration from the current 36% to 77% by 2050 to comply with emissions targets. In this regard the hybridization of hydrogen-based technologies and RES represents a reliable and versatile solution to facilitate decarbonization of the residential sector. This study provides an overview and analysis of standalone renewable hydrogen-based systems (RHS) focusing on the residential and buildings sector as well as critical infrastructures like telecom stations data servers etc. For detailed evaluation of RHS several pilot plants and real demonstration plants implemented worldwide are reviewed. To this end a techno-economic assessment of relevant parameters like self-sufficiency ratio levelized cost of energy and hydrogen roundtrip efficiency is provided. Moreover the performance of the different configurations is evaluated by comparing the installed power of each component and their energy contribution to cover the load over a defined period of time. Challenges ahead are identified for the wider deployment of RHS in the residential and buildings sector.
Collective Hydrogen Stand-alone Renewable Energy Systems for Buildings in Spain. Towards the Self-sufficiency
May 2024
Publication
The article examines the feasibility of implementing standalone hydrogen-based renewable energy systems in Spanish residential buildings specifically analyzing the optimization of a solar-battery and solar-hydrogen system for a building with 20 dwellings in Spain. The study initially assesses two standalone setups: solarbattery and solar-hydrogen. Subsequently it explores scenarios where these systems are connected to the grid to only generate and sell surplus energy. A scenario involving grid connection for self-consumption without storage serves as a benchmark for comparison. All system optimizations are designed to meet energy demands without interruptions while minimizing costs as determined by a techno-economic analysis. The systems are sized using custom software that incorporates an energy management system and employs the Jaya algorithm for optimization. The findings indicate that selling surplus energy can be economically competitive and enhance the efficiency of grid-connected self-consumption systems representing the study’s main innovation. The conclusion highlights the economic and technical potential of an autonomous hybrid energy system that includes hydrogen with the significant remaining challenge being the development of a regulatory framework to support its technical feasibility in Spain.
Techno-economic Study of Power-to-Power Renewable Energy Storage Based on the Smart Integration of Battery, Hydrogen, and Micro Gas Turbine Technologies
Mar 2023
Publication
This paper deals with the integration of a Power-to-Power Energy Storage System (P2P-ESS) based on a hydrogen driven micro gas turbine (mGT) for an off-grid application with a continuous demand of 30 kWe for three European cities: Palermo Frankfurt and Newcastle. In the first part of the analysis the results show that the latitude of the location is a very strong driver in determining the size of the system (hence footprint) and the amount of seasonal storage. The rated capacity of the PV plant and electrolyzer are 37%/41% and 58%/64% higher in Frankfurt and Newcastle respectively as compared to the original design for Palermo. And not only this but seasonal storage also increases largely from 3125 kg H2 to 5023 and 5920 kg H2 . As a consequence of this LCOE takes values of 0.86 e/kWh 1.26 e/kWh and 1.5 e/kWh for the three cities respectively whilst round-trip efficiency is approximately 15.7% for the three designs at the 3 cities. Finally with the aim to reduce the footprint and rating of the different systems a final assessment of the system hybridised with battery storage shows a 20% LCOE reduction and a 10% higher round-trip efficiency.
System-friendly Process Design: Optimizing Blue Hydrogen Production for Future Energy Systems
Aug 2022
Publication
While the effects of ongoing cost reductions in renewables batteries and electrolyzers on future energy systems have been extensively investigated the effects of significant advances in CO2 capture and storage (CCS) technologies have received much less attention. This research gap is addressed via a long-term (2050) energy system model loosely based on Germany yielding four main findings. First CCS-enabled pathways offer the greatest benefits in the hydrogen sector where hydrogen prices can be reduced by two-thirds relative to a scenario without CCS. Second advanced blue hydrogen technologies can reduce total system costs by 12% and enable negative CO2 emissions due to higher efficiencies and CO2 capture ratios. Third co-gasification of coal and biomass emerged as an important enabler of these promising results allowing efficient exploitation of limited biomass resources to achieve negative emissions and limit the dependence on imported natural gas. Finally CCS decarbonization pathways can practically and economically incorporate substantial shares of renewable energy to reduce fossil fuel dependence. Such diversification of primary energy inputs increases system resilience to the broad range of socio-techno-economic challenges facing the energy transition. In conclusion balanced blue-green pathways offer many benefits and deserve serious consideration in the global decarbonization effort.
Novel Use of Green Hydrogen Fuel Cell-Based Combined Heat and Power Systems to Reduce Primary Energy Intake and Greenhouse Emissions in the Building Sector
Feb 2021
Publication
Achieving European climate neutrality by 2050 requires further efforts not only from the industry and society but also from policymakers. The use of high-efficiency cogeneration facilities will help to reduce both primary energy consumption and CO2 emissions because of the increase in overall efficiency. Fuel cell-based cogeneration technologies are relevant solutions to these points for small- and microscale units. In this research an innovative and new fuel cell-based cogeneration plant is studied and its performance is compared with other cogeneration technologies to evaluate the potential reduction degree in energy consumption and CO2 emissions. Four energy consumption profile datasets have been generated from real consumption data of different dwellings located in the Mediterranean coast of Spain to perform numerical simulations in different energy scenarios according to the fuel used in the cogeneration. Results show that the fuel cell-based cogeneration systems reduce primary energy consumption and CO2 emissions in buildings to a degree that depends on the heat-to-power ratio of the consumer. Primary energy consumption varies from 40% to 90% of the original primary energy consumption when hydrogen is produced from natural gas reforming process and from 5% to 40% of the original primary energy consumption if the cogeneration is fueled with hydrogen obtained from renewable energy sources. Similar reduction degrees are achieved in CO2 emissions.
Review and Survey of Methods for Analysis of Impurities in Hydrogen for Fuel Cell Vehicles According to ISO 14687:2019
Feb 2021
Publication
Gaseous hydrogen for fuel cell electric vehicles must meet quality standards such as ISO 14687:2019 which contains maximal control thresholds for several impurities which could damage the fuel cells or the infrastructure. A review of analytical techniques for impurities analysis has already been carried out by Murugan et al. in 2014. Similarly this document intends to review the sampling of hydrogen and the available analytical methods together with a survey of laboratories performing the analysis of hydrogen about the techniques being used. Most impurities are addressed however some of them are challenging especially the halogenated compounds since only some halogenated compounds are covered not all of them. The analysis of impurities following ISO 14687:2019 remains expensive and complex enhancing the need for further research in this area. Novel and promising analyzers have been developed which need to be validated according to ISO 21087:2019 requirements.
Integration of a Multi-Stack Fuel Cell System in Microgrids: A Solution Based on Model Predictive Control
Sep 2020
Publication
This paper proposes a multi-objective model predictive control (MPC) designed for the power management of a multi-stack fuel cell (FC) system integrated into a renewable sources-based microgrid. The main advantage of MPC is the fact that it allows the current timeslot to be optimized while taking future timeslots into account. The multi-objective function solves the problem related to the power dispatch at time that includes criteria to reduce the multi-stack FC degradation operating and maintenance costs as well as hydrogen consumption. Regarding the scientific literature the novelty of this paper lies in the proposal of a generalized MPC controller for a multi-stack FC that can be used independently of the number of stacks that make it up. Although all the stacks that make up the modular FC system are identical their levels of degradation in general will not be. Thus over time each stack can present a different behavior. Therefore the power control strategy cannot be based on an equal distribution according to the nominal power of each stack. On the contrary the control algorithm should take advantage of the characteristics of the multi-stack FC concept distributing operation across all the stacks regarding their capacity to produce power/energy and optimizing the overall performance.
On Green Hydrogen Generation Technologies: A Bibliometric Review
Mar 2024
Publication
Green hydrogen produced by water electrolysis with renewable energy plays a crucial role in the revolution towards energy sustainability and it is considered a key source of clean energy and efficient storage. Its ability to address the intermittency of renewable sources and its potential to decarbonize sectors that are difficult to electrify make it a strategic component in climate change mitigation. By using a method based on a bibliometric review of scientific publications this paper represents a significant contribution to the emerging field of research on green hydrogen and provides a detailed review of electrolyzer technologies identifying key areas for future research and technology development. The results reflect the immaturity of a technology which advances with different technical advancements waiting to find the optimal technical solution that allows for its massive implementation as a source of green hydrogen generation. According to the results found in this article alkaline (ALK) and proton exchange membrane (PEM) electrolyzers seem to be the ones that interest the scientific community the most. Similarly in terms of regional analysis Europe is clearly committed to green hydrogen in view of the analysis of its scientific results on materials and electrolyzer capacity forecasts for 2030.
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.
Optimal Energy Management in a Standalone Microgrid, with Photovoltaic Generation, Short-Term Storage, and Hydrogen Production
Mar 2020
Publication
This paper addresses the energy management of a standalone renewable energy system. The system is configured as a microgrid including photovoltaic generation a lead-acid battery as a short term energy storage system hydrogen production and several loads. In this microgrid an energy management strategy has been incorporated that pursues several objectives. On the one hand it aims to minimize the amount of energy cycled in the battery in order to reduce the associated losses and battery size. On the other hand it seeks to take advantage of the long-term surplus energy producing hydrogen and extracting it from the system to be used in a fuel cell hybrid electric vehicle. A crucial factor in this approach is to accommodate the energy consumption to the energy demand and to achieve this a model predictive control (MPC) scheme is proposed. In this context proper models for solar estimation hydrogen production and battery energy storage will be presented. Moreover the controller is capable of advancing or delaying the deferrable loads from its prescheduled time. As a result a stable and efficient supply with a relatively small battery is obtained. Finally the proposed control scheme has been validated on a real case scenario.
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.
Chilean National Green Hydrogen Strategy
Nov 2020
Publication
Like hydrogen Chile is small by nature and accordingly contributes just 0.3% to global greenhouse gas emissions. However we too have an outsized role to play in turning the tide on rising emissions and pursuing a low carbon path to growth and development.<br/>What we lack in size we more than make up for in potential. In the desert in the North with the highest solar irradiance on the planet and in the Patagonia in the South with strong and consistent winds we have the renewable energy potential to install 70 times the electricity generation capacity we have today. This abundant renewable energy will enable us to become the cheapest producer of green hydrogen on Earth. Our National Green Hydrogen Strategy is aimed at turning this promise into reality.<br/>The Strategy is the result of collaborative work between industry academia civil society and the public sector and is an essential piece of our carbon neutrality plan and commitment to sustainable development. It will allow us to produce and export products that are created using zero carbon fuels distinguishing our exports as clean products for end users. It will also enable us to export our renewable energy to the world in the form of green liquid hydrogen green ammonia and clean synthetic fuels.<br/>Traditionally Chile lacked fossil fuels and was forced to import the energy it required. Now the coming of age of the tiniest atom will allow us to drive deep decarbonization in our own country and throughout the world. This Strategy is the first step for Chile in embracing this promise and fulfilling its new potential.
Perspectives on Hydrogen
Dec 2022
Publication
Humankind has an urgent need to reduce carbon dioxide emissions. Such a challenge requires deep transformation of the current energy system in our society. Achieving this goal has given an unprecedented role to decarbonized energy vectors. Electricity is the most consolidated of such vectors and a molecular vector is in the agenda to contribute in the future to those end uses that are difficult to electrify. Additionally energy storage is a critical issue for both energy vectors. In this communication discussion on the status hopes and perspectives of the hydrogen contribution to decarbonization are presented emphasizing bottlenecks in key aspects such as education reskilling and storage capacity and some concerns about the development of a flexible portfolio of technologies that could affect the contribution and impact of the whole hydrogen value chain in society. This communication would serve to the debate and boost discussion about the topic.
Decarbonizing the Spanish Transportation Sector by 2050: Design and Techno-economic Assessment of the Hydrogen Generation and Supply Chain
May 2023
Publication
The transport sector is difficult to decarbonize due to its high reliance on fossil fuels accounting for 37% of global end-use sectors emissions in 2021. Therefore this work proposes an energy model to replace the Spanish vehicle fleet by hydrogen-fueled vehicles by 2050. Thus six regions are defined according to their proximity to regasification plants where hydrogen generation hubs are implemented. Likewise renewables deployment is subject to their land availability. Hydrogen is transported through an overhauled primary natural gas transport network while two distribution methods are compared for levelized cost of hydrogen minimization: gaseous pipeline vs liquid hydrogen supply in trucks. Hence a capacity of 443.1 GW of renewables 214 GW of electrolyzers and 3.45 TWh of hydrogen storage is required nationwide. Additionally gaseous hydrogen distribution is on average 17% cheaper than liquid hydrogen delivery. Finally all the regions present lower prices per km traveled than gasoline or diesel.
Concept Design and Energy Balance Optimization of a Hydrogen Fuel Cell Helicoptor for Unmanned Aerial Vehicle and Aerotaxi Applications
May 2023
Publication
In the new scenario where the transportation sector must be decarbonized to limit global warming fuel cellpowered aerial vehicles have been selected as a strategic target application to compose part of the urban fleet to minimize road transport congestion and make goods and personal transportation fast and efficient. To address the necessity of clean and efficient urban air transport this work consists of the conceptual development of a lightweight rotary-winged transport vehicle using a hydrogen-based fuel cell propulsion system and the optimization of its energy balance. For that purpose the methods for integrating the coupled aerodynamic and propulsion system sizing and optimization was developed with the aim of designing concepts capable of carrying 0 (unmanned aerial vehicle — Design 1) and 1 (Aerotaxi — Design 2) passengers for a distance of 300 km at a cruise altitude of 500 m with a minimum climbing rate capability of 6 m s−1 at 1000 m. The results show how these designs with the desired performance specifications can be obtained with a vehicle mass ranging from 416 to 648 kg depending on the application and with specific range and endurance respectively within 46.2–47.8 km/kg and 20.4–21.3 min/kg for design 1 and 33.3–33.8 km/kg and 12.5–13.9 min/kg for design 2.
Risk Management of Energy Communities with Hydrogen Production and Storage Technologies
Jul 2023
Publication
The distributed integration of renewable energy sources plays a central role in the decarbonization of economies. In this regard energy communities arise as a promising entity to coordinate groups of proactive consumers (prosumers) and incentivize investment on clean technologies. However the uncertain nature of renewable energy generation residential loads and trading tariffs pose important challenges both at the operational and economic levels. We study how this management can be directly undertaken by an arbitrageur that making use of an adequate price-based demand response (real-time pricing) system serves as an intermediary with the central electricity market to coordinate different types of prosumers under risk aversion. In particular we consider a sequential futures and spot market where the aggregated shortage or excess of energy within the community can be traded. We aim to study the impact of new hydrogen production and storage technologies on community operation and risk management. These interactions are modeled as a game theoretical setting in the form of a stochastic two-stage bilevel optimization problem which is later reformulated without approximation as a single-level mixed-integer linear problem (MILP). An extensive set of numerical experiments based on real data is performed to study the operation of the energy community under different technical and economical conditions. Results indicate that the optimal involvement in futures and spot markets is highly conditioned by the community’s risk aversion and self-sufficiency levels. Moreover the external hydrogen market has a direct effect on the community’s internal price-tariff system and depending on the market conditions may worsen the utility of individual prosumers.
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