Spain
Can an Energy Only Market Enable Resource Adequacy in a Decarbonized Power System? A Co-simulation with Two Agent-based-models
Feb 2024
Publication
Future power systems in which generation will come almost entirely from variable Renewable Energy Sources (vRES) will be characterized by weather-driven supply and flexible demand. In a simulation of the future Dutch power system we analyze whether there are sufficient incentives for market-driven investors to provide a sufficient level of security of supply considering the profit-seeking and myopic behavior of investors. We cosimulate two agent-based models (ABM) one for generation expansion and one for the operational time scale. The results suggest that in a system with a high share of vRES and flexibility prices will be set predominantly by the demand’s willingness to pay particularly by the opportunity cost of flexible hydrogen electrolyzers. The demand for electric heating could double the price of electricity in winter compared to summer and in years with low vRES could cause shortages. Simulations with stochastic weather profiles increase the year-to-year variability of cost recovery by more than threefold and the year-to-year price variability by more than tenfold compared to a scenario with no weather uncertainty. Dispatchable technologies have the most volatile annual returns due to high scarcity rents during years of low vRES production and diminished returns during years with high vRES production. We conclude that in a highly renewable EOM investors would not have sufficient incentives to ensure the reliability of the system. If they invested in such a way to ensure that demand could be met in a year with the lowest vRES yield they would not recover their fixed costs in the majority of years.
Toward Sustainability: An Overview of the Use of Green Hydrogen in the Agriculture and Livestock Sector
Aug 2023
Publication
The agro-livestock sector produces about one third of global greenhouse gas (GHG) emissions. Since more energy is needed to meet the growing demand for food and the industrial revolution in agriculture renewable energy sources could improve access to energy resources and energy security reduce dependence on fossil fuels and reduce GHG emissions. Hydrogen production is a promising energy technology but its deployment in the global energy system is lagging. Here we analyzed the theoretical and practical application of green hydrogen generated by electrolysis of water powered by renewable energy sources in the agro-livestock sector. Green hydrogen is at an early stage of development in most applications and barriers to its large-scale deployment remain. Appropriate policies and financial incentives could make it a profitable technology for the future.
Biological Hydrogen Methanation with Carbon Dioxide Utilization: Methanation Acting as Mediator in the Hydrogen Economy
May 2023
Publication
Hydrogen is one of the main energy carriers playing a prominent role in the future decarbonization of the economy. However several aspects regarding the transport and storage of this gas are challenging. The intermediary conversion of hydrogen into high-density energy molecules may be a crucial step until technological conditions are ready to attain a significant reduction in fossil fuel use in transport and the industrial sector. The process of transforming hydrogen into methane by anaerobic digestion is reviewed showing that this technology is a feasible option for facilitating hydrogen storage and transport. The manuscript focuses on the role of anaerobic digestion as a technology driver capable of fast adaptation to current energy needs. The use of thermophilic systems and reactors capable of increasing the contact between the H2 -fuel and liquid phase demonstrated outstanding capabilities attaining higher conversion rates and increasing methane productivity. Pressure is a relevant factor of the process allowing for better hydrogen solubility and setting the basis for considering feasible underground hydrogen storage concomitant with biological methanation. This feature may allow the integration of sequestered carbon dioxide as a relevant substrate.
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.
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.
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.
Hydrogen-powered Refrigeration System for Environmentally Friendly Transport and Delivery in the Food Supply Chain
Mar 2023
Publication
Urban population and the trend towards online commerce leads to an increase in delivery solution in cities. The growth of the transport sector is very harmful to the environment being responsible for approximately 40% of greenhouse gas emissions in the European Union. The problem is aggravated when transporting perishable foodstuffs as the vehicle propulsion engine (VPE) must power not only the vehicle but also the refrigeration unit. This means that the VPE must be running continuously both on the road and stationary (during delivery) as the cold chain must be preserved. The result is costly (high fuel consumption) and harmful to the environment. At present refrigerated transport does not support full-electric solutions due to the high energy consumption required which motivates the work presented in this article. It presents a turnkey solution of a hydrogen-powered refrigeration system (HPRS) to be integrated into standard light trucks and vans for short-distance food transport and delivery. The proposed solution combines an air-cooled polymer electrolyte membrane fuel cell (PEMFC) a lithium-ion battery and low-weight pressurised hydrogen cylinders to minimise cost and increase autonomy and energy density. In addition for its implementation and integration all the acquisition power and control electronics necessary for its correct management have been developed. Similarly an energy management system (EMS) has been developed to ensure continuity and safety in the operation of the electrical system during the working day while maximizing both the available output power and lifetime of the PEMFC. Experimental results on a real refrigerated light truck provide more than 4 h of autonomy in intensive intercity driving profiles which can be increased if necessary by simply increasing the pressure of the stored hydrogen from the current 200 bar to whatever is required. The correct operation of the entire HPRS has been experimentally validated in terms of functionality autonomy and safety; with fuel savings of more than 10% and more than 3650 kg of CO2/ year avoided.
Decarbonization Pathways, Strategies, and Use Cases to Achieve Net-Zero CO2 Emissions in the Steelmaking Industry
Oct 2023
Publication
The steelmaking industry is responsible for 7% of global CO2 emissions making decarbonization a significant challenge. This review provides a comprehensive analysis of current steel-production processes assessing their environmental impact in terms of CO2 emissions at a global level. Limitations of the current pathways are outlined by using objective criteria and a detailed review of the relevant literature. Decarbonization strategies are rigorously evaluated across various scenarios emphasizing technology feasibility. Focusing on three pivotal areas—scrap utilization hydrogen integration and electricity consumption—in-depth assessments are provided backed by notable contributions from both industrial and scientific fields. The intricate interplay of technical economic and regulatory considerations substantially affects CO2 emissions particularly considering the EU Emissions Trading System. Leading steel producers have established challenging targets for achieving carbon neutrality requiring a thorough evaluation of industry practices. This paper emphasizes tactics to be employed within short- medium- and long-term periods. This article explores two distinct case studies: One involves a hot rolling mill that utilizes advanced energy techniques and uses H2 for the reheating furnace resulting in a reduction of 229 kt CO2 -eq per year. The second case examines DRI production incorporating H2 and achieves over 90% CO2 reduction per ton of DRI.
Battery and Hydrogen Energy Storage Control in a Smart Energy Network with Flexible Energy Demand Using Deep Reinforcement Learning
Sep 2023
Publication
Smart energy networks provide an effective means to accommodate high penetrations of variable renewable energy sources like solar and wind which are key for the deep decarbonisation of energy production. However given the variability of the renewables as well as the energy demand it is imperative to develop effective control and energy storage schemes to manage the variable energy generation and achieve desired system economics and environmental goals. In this paper we introduce a hybrid energy storage system composed of battery and hydrogen energy storage to handle the uncertainties related to electricity prices renewable energy production and consumption. We aim to improve renewable energy utilisation and minimise energy costs and carbon emissions while ensuring energy reliability and stability within the network. To achieve this we propose a multi-agent deep deterministic policy gradient approach which is a deep reinforcement learning-based control strategy to optimise the scheduling of the hybrid energy storage system and energy demand in real time. The proposed approach is model-free and does not require explicit knowledge and rigorous mathematical models of the smart energy network environment. Simulation results based on real-world data show that (i) integration and optimised operation of the hybrid energy storage system and energy demand reduce carbon emissions by 78.69% improve cost savings by 23.5% and improve renewable energy utilisation by over 13.2% compared to other baseline models; and (ii) the proposed algorithm outperforms the state-of-the-art self-learning algorithms like the deep-Q network.
Exploring the Potential of Green Hydrogen Production and Application in the Antofagasta Region of Chile
Jun 2023
Publication
Green hydrogen is gaining increasing attention as a key component of the global energy transition towards a more sustainable industry. Chile with its vast renewable energy potential is well positioned to become a major producer and exporter of green hydrogen. In this context this paper explores the prospects for green hydrogen production and use in Chile. The perspectives presented in this study are primarily based on a compilation of government reports and data from the scientific literature which primarily offer a theoretical perspective on the efficiency and cost of hydrogen production. To address the need for experimental data an ongoing experimental project was initiated in March 2023. This project aims to assess the efficiency of hydrogen production and consumption in the Atacama Desert through the deployment of a mobile on-site laboratory for hydrogen generation. The facility is mainly composed by solar panels electrolyzers fuel cells and a battery bank and it moves through the Atacama Desert in Chile at different altitudes from the sea level to measure the efficiency of hydrogen generation through the energy approach. The challenges and opportunities in Chile for developing a robust green hydrogen economy are also analyzed. According to the results Chile has remarkable renewable energy resources particularly in solar and wind power that could be harnessed to produce green hydrogen. Chile has also established a supportive policy framework that promotes the development of renewable energy and the adoption of green hydrogen technologies. However there are challenges that need to be addressed such as the high capital costs of green hydrogen production and the need for supportive infrastructure. Despite these challenges we argue that Chile has the potential to become a leading producer and exporter of green hydrogen or derivatives such as ammonia or methanol. The country’s strategic location political stability and strong commitment to renewable energy provide a favorable environment for the development of a green hydrogen industry. The growing demand for clean energy and the increasing interest in decarbonization present significant opportunities for Chile to capitalize on its renewable energy resources and become a major player in the global green hydrogen market.
Numerical Study on the Use of Ammonia/Hydrogen Fuel Blends for Automotive Sparking-ignition Engines
Jun 2023
Publication
The importance of new alternative fuels has assumed great relevance in the last decades to face the issues of global warming and pollutant emissions from energy production. The scientific community is responsible for developing solutions to achieve the necessary environmental restriction policies. In this context ammonia appears as a potential fuel candidate and energy vector that may solve the technological difficulties of using hydrogen (H2 ) directly in internal combustion engines. Its high hydrogen content per unit mass higher energy density than liquid hydrogen well-developed infrastructure and experience in handling and storage make it suitable to be implemented as a long-term solution. In this work a virtual engine model was developed to perform prospective simulations of different operating conditions using ammonia and H2 -enriched ammonia as fuel in a spark-ignition (SI) engine integrating a chemical kinetics model and empirical correlations for combustion prediction. In addition specific conditions were evaluated to consider and to understand the governing parameters of ammonia combustion using computational fluid dynamics (CFD) simulations. Results revealed similar thermal efficiency than methane fuel with considerable improvements after appropriate H2 - enrichment. Moreover increasing the intake temperature and the turbulence intensity inside the cylinder evinced significant reductions in combustion duration. Finally higher compression ratios ensure efficiency gains with no evidence of abnormal combustion (knocking) even at high compression ratios (above 16:1) and low engine speeds (800 rpm). Numerical simulations showed the direct influence of the flame front surface area and the turbulent combustion velocity on efficiency reflecting the need for optimizing the SI engines design paradigm for ammonia applications.
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.
Review of the Planning and Distribution Methodologies to Locate Hydrogen Infrastructure in the Territory
Jan 2024
Publication
The member countries of the European Union (EU) have prioritized the incorporation of hydrogen as a key component of their energy objectives. As the world moves towards reducing its dependence on fossil fuels alternative sources of energy have gained prominence. With the growing development of Fuel Cell Electric Vehicles (FCEVs) the establishment of an infrastructure for hydrogen production and the creation of a network of service stations have become essential. This article’s purpose is to conduct a methodical review of literature regarding the use of green hydrogen for transportation and the planning of imperative infrastructure in the territory of the EU specifically Hydrogen Refueling Stations (HRS). In order to increase the acceptance of fuel cell vehicles a comprehensive network of hydrogen refueling stations (HRS) must be built that enable drivers to refuel their vehicles quickly and easily similar to gasoline or diesel vehicles. The literature review on this topic was conducted using the Web of Science database (WOS) with a variety of search terms proposed to cover all the key components of green hydrogen production and refueling infrastructure. The implementation of HRS powered by renewable energy sources is an important step in the adoption of fuel cell vehicles and overcoming the obstacles that come with their implementation will require cooperation and innovation from governments private businesses and other stakeholders.
Sustainable Propulsion Alternatives in Regional Aviation: The Case of the Canary Islands
May 2023
Publication
Sustainability is one of the main challenges the aviation industry is currently facing. In a global context of energy transition towards cleaner and renewable sources the sector is developing technologies to fly more efficiently and mitigate its environmental impact. Innovative propulsion alternatives such as biofuels electric aircraft and hydrogen engines are already a reality or are close to becoming so. To assess their feasibility a study is conducted on specific routes and aircraft across different flight ranges. The analysis focuses on the Canary Islands an outermost region of the EU with high mobility and no comparable alternative means of transport. For three routes flight profiles are analyzed obtaining the fuel consumption and emissions generated by the conventional propulsion and later applying the sustainable alternatives. The results indicate optimistic perspectives with reductions in environmental impact ranging between 40% and 75% compared to the present.
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.
Multilevel Governance, PV Solar Energy, and Entrepreneurship: The Generation of Green Hydrogen as a Fuel of Renewable Origin
Sep 2022
Publication
In Spain the institutional framework for photovoltaic energy production has experienced distinct stages. From 2007 to 2012 the feed-in-tariff system led to high annual growth rates of this renewable energy but after the suppression of the policy of public subsidies the sector stagnated. In recent years green hydrogen an innocuous gas in the atmosphere has become a driving force that stimulates photovoltaic energy production. Since 2020 encouraged by the European energy strategies and corresponding funds Spain has established a regulation to promote green hydrogen as a form of energy resource. Adopting the new institutional economics (NIE) approach this article investigates the process of changing incentives for the energy business sector and its impact on photovoltaic energy production. The results show an increase in the number of both projects approved or on approval and companies involved in green hydrogen that are planning to use photovoltaic energy in Spain thus engendering the creation of a new photovoltaic business environment based on innovation and sustainability.
Optimisation of Size and Control Strategy in Utility-scale of Green Hydrogen Production Systems
Aug 2023
Publication
The optimisation of green hydrogen production systems is challenging. Moreover an accurate simulation of the system is required for effective optimisation. This study presents a novel method for optimising utility-scale hybrid photovoltaice-wind systems for hydrogen production using accurate simulation models. The optimisation objective is to minimise the levelised cost of hydrogen (LCOH) using genetic algorithms. Different types of systems (such as islanded systems grid-connected systems with or without the possibility of purchasing electricity from the grid and grid-connected systems considering power curtailment) are evaluated and optimised. Each combination of components and control strategy is simulated during the system lifetime (20 yrs) in time steps of 5 min considering the degradation of renewable generators during the system lifetime and different real-time pricing curves and renewable resource curves for each year of the system lifetime. Accurate models are used in the simulations including electrolyser efficiency dependent on the input power and cold-start extra ageing. An application example located in Zaragoza (Spain) is shown obtaining LCOH from 4.74 to 16.06 V/kg depending on the type of project and electrolyser.
Current State of Technology of Fuel Cell Power Systems for Autonomous Underwater Vehicles
Jul 2014
Publication
Autonomous Underwater Vehicles (AUVs) are vehicles that are primarily used to accomplish oceanographic research data collection and auxiliary offshore tasks. At the present time they are usually powered by lithium-ion secondary batteries which have insufficient specific energies. In order for this technology to achieve a mature state increased endurance is required. Fuel cell power systems have been identified as an effective means to achieve this endurance but no implementation in a commercial device has yet been realized. This paper summarizes the current state of development of the technology in this field of research. First the most adequate type of fuel cell for this application is discussed. The prototypes and design concepts of AUVs powered by fuel cells which have been developed in the last few years are described. Possible commercial and experimental fuel cell stack options are analyzed examining solutions adopted in the analogous aerial vehicle applications as well as the underwater ones to see if integration in an AUV is feasible. Current solutions in oxygen and hydrogen storage systems are overviewed and energy density is objectively compared between battery power systems and fuel cell power systems for AUVs. A couple of system configuration solutions are described including the necessary lithium-ion battery hybrid system. Finally some closing remarks on the future of this technology are given.
Study on Hydrogen Substitution in a Compressed Natural Gas Spark-ignition Passenger Car Engine
Jun 2023
Publication
Hydrogen substitution in applications fueled by compressed natural gas arises as a potential alternative to fossil fuels and it may be the key to an effective hydrogen economy transition. The reduction of greenhouse gas emissions especially carbon dioxide and unburned methane as hydrogen is used in transport and industry applications makes its use an attractive option for a sustainable future. The purpose of this research is to examine the gradual adoption of hydrogen as a fuel for light-duty transportation. Particularly the study focuses on evaluating the performance and emissions of a single-cylinder port fuel injection spark-ignition engine as hydrogen is progressively increased in the natural gas-based fuel blend. Results identify the optimal conditions for air dilution and engine operation parameters to achieve the best performance. They corroborate that the dilution rate has to be adjusted to control pollutant emissions as the percentage of hydrogen is increased. Moreover the study identifies the threshold for hydrogen substitution below which the reduction of carbon dioxide emissions due to efficiency gains is negligible compared to the reduction of the carbon content in the fuel blend. These findings will help reduce the environmental footprint of light-duty transportation not only in the long term but also in the short and medium terms.
Impact of Medium-pressure Direct Injection Engine Fueled by Hydrogen
Dec 2023
Publication
In the automotive sector hydrogen is being increasingly explored as an alternative fuel to replace conventional carbon-based fuels. Its combustion characteristics make it well-suited for adaptation to internal combustion engines. The wide flammability range of hydrogen allows for higher dilution conditions resulting in enhanced combustion efficiency. When combined with lean combustion strategies hydrogen significantly reduces environmental impact virtually eliminating carbon dioxide and nitrogen oxide emissions while maintaining high thermal efficiency. This paper aims to assess the potential of using an outwardly opening poppet valve hydrogen direct injection (DI) system in a small engine for light-duty applications. To achieve this a comparison of performance emission levels and combustion parameters is conducted on a single-cylinder spark-ignition (SI) research engine fueled by hydrogen using both port fuel injection (PFI) and this new direct injection system. Two different engine loads are measured at multiple air dilution and injection timing conditions. The results demonstrate notable efficiency improvements ranging from 0.6% to 1.1% when transitioning from PFI to DI. Accurate control of injection timing is essential for achieving optimal performance and low emissions. Delaying the start of injection results in a 7.6% reduction in compression work at low load and a 3.9% reduction at high load. This results in a 3.1-3.2% improvement in ISFC in both load conditions considered.
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