Italy
Renewable Hydrogen Potential for Low-carbon Retrofit of the Building Stocks
Dec 2015
Publication
Energy-related GHG emissions mainly from fossil fuels combustion account for around 70% of total emissions. Those emissions are the target of the recent sustainability policies. Indeed renewables exploitation is considered widely the weapon to deal with this challenge thanks to their carbon neutrality. But the biggest drawback is represented by the mismatching between their production and users consumption. The storage would be a possible solution but its viability consists of economic sustainability and energy process efficiency as well. The cutting edge technologies of batteries have not still solved these issues at the same time. So a paradigm shift towards the identification of an energy carrier as storage option the so called Power-to-Gas could be the viable solution. From viability to feasibility a mandatory step is required: the opportunity to integrate the new solution in the proven infrastructures system. Thus the recent studies on Hydrogen (H2) enrichment in Natural Gas demonstrating a lower environmental impact and an increase in energy performance are the base to build the hydrogen transition in the urban environment. The aim of this paper is to evaluate the environmental benefits at building and district scale.
Analysis of the Existing Barriers for the Market Development of Power to Hydrogen (P2H) in Italy
Sep 2020
Publication
New technological solutions are required to control the impact of the increasing presence of renewable energy sources connected to the electric grid that are characterized by unpredictable production (i.e. wind and solar energy). Energy storage is becoming essential to stabilize the grid when a mismatch between production and demand occurs. Among the available solutions Power to Hydrogen (P2H) is one of the most attractive options. However despite the potential many barriers currently hinder P2H market development. The literature reports general barriers and strategies to overcome them but a specific analysis is fundamental to identifying how these barriers concretely arise in national and regional frameworks since tailored solutions are needed to foster the development of P2H local market. The paper aims to identify and to analyze the existing barriers for P2H market uptake in Italy. The paper shows how several technical regulatory and economic issues are still unsolved resulting in a source of uncertainty for P2H investment. The paper also suggests possible approaches and solutions to address the Italian barriers and to support politics and decision-makers in the definition and implementation of the national hydrogen strategy.
Delivering Net-zero Carbon Heat: Technoeconomic and Whole-system Comparisons of Domestic Electricity- and Hydrogen-driven Technologies in the UK
Apr 2022
Publication
Proposed sustainable transition pathways for moving away from natural gas in domestic heating focus on two main energy vectors: electricity and hydrogen. Electrification would be implemented by using vapourcompression heat pumps which are currently experiencing market growth in many countries. On the other hand hydrogen could substitute natural gas in boilers or be used in thermally–driven absorption heat pumps. In this paper a consistent thermodynamic and economic methodology is developed to assess the competitiveness of these options. The three technologies along with the option of district heating are for the first time compared for different weather/ambient conditions and fuel-price scenarios first from a homeowner’s and then from a wholeenergy system perspective. For the former two-dimensional decision maps are generated to identify the most cost-effective technologies for different combinations of fuel prices. It is shown that in the UK hydrogen technologies are economically favourable if hydrogen is supplied to domestic end-users at a price below half of the electricity price. Otherwise electrification and the use of conventional electric heat pumps will be preferred. From a whole-energy system perspective the total system cost per household (which accounts for upstream generation and storage as well as technology investment installation and maintenance) associated with electric heat pumps varies between 790 and 880 £/year for different scenarios making it the least-cost decarbonisation pathway. If hydrogen is produced by electrolysis the total system cost associated with hydrogen technologies is notably higher varying between 1410 and 1880 £/year. However this total system cost drops to 1150 £/year with hydrogen produced cost-effectively by methane reforming and carbon capture and storage thus reducing the gap between electricity- and hydrogen-driven technologies.
Minimum Emissions Configuration of a Green Energy–Steel System: An Analytical Model
May 2022
Publication
The need to significantly reduce emissions from the steelmaking sector requires effective and ready-to-use technical solutions. With this aim different decarbonization strategies have been investigated by both researchers and practitioners. To this concern the most promising pathway is represented by the replacement of natural gas with pure hydrogen in the direct reduced iron (DRI) production process to feed an electric arc furnace (EAF). This solution allows to significantly reduce direct emissions of carbon dioxide from the DRI process but requires a significant amount of electricity to power electrolyzers adopted to produce hydrogen. The adoption of renewable electricity sources (green hydrogen) would reduce emissions by 95–100% compared to the blast furnace–basic oxygen furnace (BF–BOF) route. In this work an analytical model for the identification of the minimum emission configuration of a green energy–steel system consisting of a secondary route supported by a DRI production process and a renewable energy conversion system is proposed. In the model both technological features of the hydrogen steel plant and renewable energy production potential of the site where it is to be located are considered. Compared to previous studies the novelty of this work consists of the joint modeling of a renewable energy system and a steel plant. This allows to optimize the overall system from an environmental point of view considering the availability of green hydrogen as an inherent part of the model. Numerical experiments proved the effectiveness of the model proposed in evaluating the suitability of using green hydrogen in the steelmaking process. Depending on the characteristics of the site and the renewable energy conversion system adopted decreases in emissions ranging from 60% to 91% compared to the BF–BOF route were observed for the green energy–steel system considered It was found that the environmental benefit of using hydrogen in the secondary route is strictly related to the national energy mix and to the electrolyzers’ technology. Depending on the reference context it was found that there exists a maximum value of the emission factor from the national electricity grid below which is environmentally convenient to produce DRI by using only hydrogen. It was moreover found that the lower the electricity consumption of the electrolyzer the higher the value assumed by the emission factor from the electricity grid which makes the use of hydrogen convenient.
Willingness to Pay and Public Acceptance for Hydrogen Buses: A Case Study of Perugia
Sep 2015
Publication
Sustainability transportation is characterized by a positive externality on the environment health social security land use and social inclusion. The increasing interest in global warming has caused attention to be paid to the introduction of the hydrogen bus (H2B). When introducing new environmental technologies such as H2B it is often necessary to assess the environmental benefits related to this new technology. However such benefits are typically non-priced due to their public good nature. Therefore we have to address this problem using the contingent valuation (CV) method. This method has been developed within environmental economics as a means to economically assess environmental changes which are typically not traded in the market. So far several big cities have been analyzed to evaluate the perceived benefit related to H2B introduction but to the best of our knowledge no one has performed a CV analysis of a historical city where smog also damages historical buildings. This paper presents the results obtained using a multi-wave survey. We have investigated user preferences to elicit their willingness to pay for H2B introduction in Perugia taking into account all types of negative externalities due to the traffic pollution. The results confirm that residents in Perugia are willing to pay extra to support the introduction of H2B.
Comprehensive Review on Fuel Cell Technology for Stationary Applications as Sustainable and Efficient Poly-Generation Energy Systems
Aug 2021
Publication
Fuel cell technologies have several applications in stationary power production such as units for primary power generation grid stabilization systems adopted to generate backup power and combined-heat-and-power configurations (CHP). The main sectors where stationary fuel cells have been employed are (a) micro-CHP (b) large stationary applications (c) UPS and IPS. The fuel cell size for stationary applications is strongly related to the power needed from the load. Since this sector ranges from simple backup systems to large facilities the stationary fuel cell market includes few kWs and less (micro-generation) to larger sizes of MWs. The design parameters for the stationary fuel cell system differ for fuel cell technology (PEM AFC PAFC MCFC and SOFC) as well as the fuel type and supply. This paper aims to present a comprehensive review of two main trends of research on fuel-cell-based poly-generation systems: tracking the market trends and performance analysis. In deeper detail the present review will list a potential breakdown of the current costs of PEM/SOFC production for building applications over a range of production scales and at representative specifications as well as broken down by component/material. Inherent to the technical performance a concise estimation of FC system durability efficiency production maintenance and capital cost will be presented.
A Battery-Free Sustainable Powertrain Solution for Hydrogen Fuel Cell City Transit Bus Application
Apr 2022
Publication
The paper presents a sustainable electric powertrain for a transit city bus featuring an electrochemical battery-free power unit consisting of a hydrogen fuel cell stack and a kinetic energy storage system based on high-speed flywheels. A rare-earth free high-efficiency motor technology is adopted to pursue a more sustainable vehicle architecture by limiting the use of critical raw materials. A suitable dynamic energetic model of the full vehicle powertrain has been developed to investigate the feasibility of the traction system and the related energy management control strategy. The model includes losses characterisation as a function of the load of the main components of the powertrain by using experimental tests and literature data. The performance of the proposed solution is evaluated by simulating a vehicle mission on an urban path in real traffic conditions. Considerations about the effectiveness of the traction system are discussed.
Graphene Oxide/metal Nanocrystal Multilaminates as the Atomic Limit for Safe and Selective Hydrogen Storage
Mar 2016
Publication
Interest in hydrogen fuel is growing for automotive applications; however safe dense solid-state hydrogen storage remains a formidable scientific challenge. Metal hydrides offer ample storage capacity and do not require cryogens or exceedingly high pressures for operation. However hydrides have largely been abandoned because of oxidative instability and sluggish kinetics. We report a new environmentally stable hydrogen storage material constructed of Mg nanocrystals encapsulated by atomically thin and gas-selective reduced graphene oxide (rGO) sheets. This material protected from oxygen and moisture by the rGO layers exhibits exceptionally dense hydrogen storage (6.5 wt% and 0.105 kg H2 per litre in the total composite). As rGO is atomically thin this approach minimizes inactive mass in the composite while also providing a kinetic enhancement to hydrogen sorption performance. These multilaminates of rGO-Mg are able to deliver exceptionally dense hydrogen storage and provide a material platform for harnessing the attributes of sensitive nanomaterials in demanding environments.
Experimental Study of Hydrogen Embrittlement in Maraging Steels
Feb 2018
Publication
This research activity aims at investigating the hydrogen embrittlement of Maraging steels in connection to real sudden failures of some of the suspension blades of the Virgo Project experimental apparatus. Some of them failed after 15 years of service in working conditions. Typically in the Virgo detector blades are loaded up to 50-60% of the material yield strength. For a deeper understanding of the failure the relationship between hydrogen concentration and mechanical properties of the material have been investigated with specimens prepared in order to simulate blade working conditions. A mechanical characterization of the material has been carried out by standard tensile testing in order to establish the effect of hydrogen content on the material strength. Further experimental activity was executed in order to characterize the fracture surface and to measure the hydrogen content. Finally some of the failed blades have been analyzed in DICI-UNIPI laboratory. The experimental results show that the blades failure can be related with the hydrogen embrittlement phenomenon.
Effects of Renewable Energy Unstable Source to Hydrogen Production: Safety Considerations
Sep 2021
Publication
Hydrogen is considered a promising energy carrier for a sustainable future when it is produced by utilizing renewable energy. Nowadays less than 4% of hydrogen production is based on electrolysis processes. Each component of a hydrogen energy system needs to be optimized to increase the operation time and system efficiency. Only in this way hydrogen produced by electrolysis processes can be competitive with the conventional fossil energy sources. As conventional electrolysers are designed for operation at fixed process conditions the implementation of fluctuating and highly intermittent renewable energy is challenging. Alkaline water electrolysis is a key technology for large-scale hydrogen production powered by renewable energy. At low power availability conventional alkaline water electrolysers show a limited part-load range due to an increased gas impurity. Explosive mixtures of hydrogen and oxygen must be prevented; thus a safety shutdown is performed when reaching specific gas contamination. The University of Pisa is setting up a dedicated laboratory including a 40-kW commercial alkaline electrolyser: the focus of the study is to analyze the safety of the electrolyser together with its performance and the real energy efficiency analyzing its operational data collected under different operating conditions affected by the unstable energy supply.
Power-to-Gas Hydrogen: Techno-economic Assessment of Processes Towards a Multi-purpose Energy Carrier
Dec 2016
Publication
The present work investigates Power-to-Gas (PtG) options for variable Renewable Electricity storage into hydrogen through low temperature (alkaline and PEM) and high-temperature (SOEC) water electrolysis technologies. The study provides the assessment of the cost of the final product when hydrogen is employed for mobility (on-site refueling stations) electricity generation (by fuel cells in Power-to-Power systems) and grid injection in the natural gas network. Costs estimations are performed for 2013-2030 scenarios. A case study on the impact of variable Renewable Electricity storage by hydrogen generation on the Italian electricity and mobility sectors is presented.
Recent Developments of Membranes and Electrocatalysts for the Hydrogen Production by Anion Exchange Membrane Water Electrolysers: A Review
Nov 2022
Publication
Hydrogen production using anion exchange membrane water electrolysis (AEMWE) offers hope to the energy crisis faced by humanity. AEM electrolysis can be coupled with intermittent and renewable energy sources as well as with the use of low-cost electrocatalysts and other low-cost stack components. In AEM water electrolysis one of the biggest advantages is the use of low-cost transition metal catalysts instead of traditional noble metal electrocatalysts. AEMWE is still in its infancy despite irregular research on catalysts and membranes. In order to generate commercially viable hydrogen AEM water electrolysis technology must be further developed including energy efficiency membrane stability stack feasibility robustness ion conductivity and cost reduction. An overview of studies that have been conducted on electrocatalysts membranes and ionomers used in the AEMWEs is here reported with the aim that AEMWE research may be made more practical by this review report by bridging technological gaps and providing practical research recommendations leading to the production of scalable hydrogen.
Modelling and Analyzing the Impact of Hydrogen Enriched Natural Gas on Domestic Gas Boilers in a Decarbonization Perspective
Aug 2020
Publication
Decarbonization of energy economy is nowadays a topical theme and several pathways are under discussion. Gaseous fuels have a fundamental role for this transition and the production of low carbon-impact fuels is necessary to deal with this challenge. The generation of renewable hydrogen is a trusted solution since this energy vector can be promptly produced from electricity and injected into the existing natural gas infrastructure granting storage capacity and easy transportation. This scenario will lead in the near future to hydrogen enrichment of natural gas whose impact on the infrastructures is being actively studied. The effect on end-user devices such as domestic gas boilers instead is still little analyzed and tested but is fundamental to be assessed. The aim of this research is to generate knowledge on the effect of hydrogen enrichment on the widely used premixed boilers: the investigations include pollutant emissions efficiency flashback and explosion hazard control system and materials selection. A model for calculating several parameters related to combustion of hydrogen enriched natural gas is presented. Guidelines for the design of new components are provided and an insight is given on the maximum hydrogen blending bearable by the current boilers.
Renewable Energy, Carbon Capture & Sequestration and Hydrogen Solutions as Enabling Technologies for Reduced CO2 Energy Transition at a National Level: An Application to the 2030 Italian National Energy Scenarios
Dec 2022
Publication
Globally climate change fossil fuel depletion and greenhouse emissions are fundamental problems requiring massive effort from the international scientific community to be addressed and solved. Following the Clean Energy for all Europeans Package (CEP) guidelines the Italian Government has established challenging and tight objectives both on energy and climate matter to be targeted by 2030. Accordingly research activities on different topics are carried out in Italy looking at the installation of intermittent renewable energy systems (IRES) implementation of carbon capture and sequestration (CCS) on existing power plants and hydrogen technology and infrastructure penetration for accomplishing the end-users demands. The optimal integration of the above-mentioned technologies is one of the most effective weapons to address these objectives. The paper investigates different energy scenarios for meeting the Italian National Energy and Climate Plan (NECP) 2030 targets showing how the combined implementation of around +12 GW of IRES and +6 GW of electrolyzers compared to the national estimates simultaneously with the CCS of around 10 Mt of CO2 per year can reduce the CO2 emissions up to about 247 Mt/year. Thanks to the adoption of the well-established software platform EnergyPlan the integration of IRES plants CCS and hydrogen-based technologies have been explored and the most successful results for concurrently reducing the impact of industrial transport residential and energy sectors and mitigating the greenhouse emissions substantially relies on the diversifications. Results show both the technical and economic convenience of a 2030 energy scenario which implements properly hydrogen IRES and CCS penetration in the energy system meeting the NECP 2030 targets and maintaining both the over-generation of the power plants below 5 TWh and the initial capital expenditure to be sustained for this scenario to occur below +80% compared to the 2019 energy scenario.
Overview of First Outcomes of PNR Project HYTUNNEL-CS
Sep 2021
Publication
Dmitry Makarov,
Donatella Cirrone,
Volodymyr V. Shentsov,
Sergii Kashkarov,
Vladimir V. Molkov,
Z. Xu,
Mike Kuznetsov,
Alexandros G. Venetsanos,
Stella G. Giannissi,
Ilias C. Tolias,
Knut Vaagsaether,
André Vagner Gaathaug,
Mark R. Pursell,
Wayne M. Rattigan,
Frank Markert,
Luisa Giuliani,
L.S. Sørensen,
A. Bernad,
Mercedes Sanz Millán,
U. Kummer,
Christian Brauner,
Paola Russo,
J. van den Berg,
F. de Jong,
Tom Van Esbroeck,
M. Van De Veire,
Didier Bouix,
Gilles Bernard-Michel,
Sergey Kudriakov,
Etienne Studer,
Domenico Ferrero,
Joachim Grüne and
G. Stern
The paper presents the first outcomes of the experimental numerical and theoretical studies performed in the funded by Fuel Cell and Hydrogen Joint Undertaking (FCH2 JU) project HyTunnel-CS. The project aims to conduct pre-normative research (PNR) to close relevant knowledge gaps and technological bottlenecks in the provision of safety of hydrogen vehicles in underground transportation systems. Pre normative research performed in the project will ultimately result in three main outputs: harmonised recommendations on response to hydrogen accidents recommendations for inherently safer use of hydrogen vehicles in underground traffic systems and recommendations for RCS. The overall concept behind this project is to use inter-disciplinary and inter-sectoral prenormative research by bringing together theoretical modelling and experimental studies to maximise the impact. The originality of the overall project concept is the consideration of hydrogen vehicle and underground traffic structure as a single system with integrated safety approach. The project strives to develop and offer safety strategies reducing or completely excluding hydrogen-specific risks to drivers passengers public and first responders in case of hydrogen vehicle accidents within the currently available infrastructure.
Optimized Design of a H2-Powered Moped for Urban Mobility
Mar 2024
Publication
Micro-mobility plays an increasingly important role in the current energy transition thanks to its low energy consumption and reduced contribution to urban congestion. In this scenario fuel cell hybrid electric vehicles have several advantages over state-of-the-art battery electric vehicles such as increased driving ranges and reduced recharge times. In this paper we study the conversion of a commercial electric moped (Askoll eS3 ®) into a fuel cell hybrid electric vehicle by finding the optimal design of the components through an optimization methodology based on backward dynamic programming. This optimal design and operation strategy can also be implemented with a rulesbased approach. The results show that a system composed of a 1 kW proton exchange membrane fuel cell a 2000 Sl metal hydride hydrogen tank and a 240 Wh buffer battery can cover the same driving range as the batteries in an electric moped (119 km). Such a hybrid system occupies considerably less volume (almost 40 L) and has a negligibly higher mass. The free volume can be used to extend the driving range up to almost three times the nominal value. Moreover by using a high-pressure composite tank it is possible to increase the mass energy density of the onboard energy storage (although compression can require up to 10% of the hydrogen’s chemical energy). The fuel cell hybrid electric vehicle can be recharged with green hydrogen that is locally produced. In detail we analyze a residential scenario and a shared mobility scenario in the small Italian city of Viterbo.
A Parametric Approach for Conceptual Integration and Performance Studies of Liquid Hydrogen Short–Medium Range Aircraft
Jul 2022
Publication
The present paper deals with the investigation at conceptual level of the performance of short–medium-range aircraft with hydrogen propulsion. The attention is focused on the relationship between figures of merit related to transport capability such as passenger capacity and flight range and the parameters which drive the design of liquid hydrogen tanks and their integration with a given aircraft geometry. The reference aircraft chosen for such purpose is a box-wing short–mediumrange airplane the object of study within a previous European research project called PARSIFAL capable of cutting the fuel consumption per passenger-kilometre up to 22%. By adopting a retrofitting approach non-integral pressure vessels are sized to fit into the fuselage of the reference aircraft under the assumption that the main aerodynamic flight mechanic and structural characteristics are not affected. A parametric model is introduced to generate a wide variety of fuselage-tank cross-section layouts from a single tank with the maximum diameter compatible with a catwalk corridor to multiple tanks located in the cargo deck and an assessment workflow is implemented to perform the structural sizing of the tanks and analyse their thermodynamic behaviour during the mission. This latter is simulated with a time-marching approach that couples the fuel request from engines with the thermodynamics of the hydrogen in the tanks which is constantly subject to evaporation and depending on the internal pressure vented-out in gas form. Each model is presented in detail in the paper and results are provided through sensitivity analyses to both the technologic parameters of the tanks and the geometric parameters influencing their integration. The guidelines resulting from the analyses indicate that light materials such as the aluminium alloy AA2219 for tanks’ structures and polystyrene foam for the insulation should be selected. Preferred values are also indicted for the aspect ratios of the vessel components i.e. central tube and endcaps as well as suggestions for the integration layout to be adopted depending on the desired trade-off between passenger capacity as for the case of multiple tanks in the cargo deck and achievable flight ranges as for the single tank in the section.
Investigating Hydrogen-Based Non-Conventional Storage for PV Power in Eco-Energetic Optimization of a Multi-Energy System
Dec 2021
Publication
Through the integration of multiple energy carriers with related technologies multi-energy systems (MES) can exploit the synergies coming from their interplay for several benefits towards decarbonization. In such a context inclusion of Power-to-X technologies in periods of excess renewable electricity supply removes the need for curtailment of renewable electricity generation. In order to achieve the environmental benefits of MES without neglecting their economic feasibility the optimal design problem is as crucial as challenging and requires the adoption of a multi-objective approach. This paper extends the results of a previous work by investigating hydrogen-based non-conventional storage for PV power in the eco-energetic optimization of an MES. The system under study consists of a reversible fuel cell (r-SOC) photovoltaic (PV) electric heat pump absorption chiller and thermal storage and allows satisfying the multi-energy needs of a residential end-user. A multi-objective linear problem is established to find the optimal MES configuration including the sizes of the involved technologies with the goal of reducing the total annual cost and the fossil primary energy input. Simulation results are compared with those obtained in previous work with a conventional nanogrid where a combined heat and power (CHP) system with gas-fired internal combustion engine and a battery were present instead of an r-SOC. The optimized configuration of the non-conventional nanogrid allows achieving a maximum primary energy reduction amounting to 66.3% compared to the conventional nanogrid. In the face of the environmental benefits the non-conventional nanogrid leads to an increase in total annual costs which compared to the conventional nanogrid is in the range of 41–65%.
Electrified Hydrogen Production from Methane for PEM Fuel Cells Feeding: A Review
May 2022
Publication
The greatest challenge of our times is to identify low cost and environmentally friendly alternative energy sources to fossil fuels. From this point of view the decarbonization of industrial chemical processes is fundamental and the use of hydrogen as an energy vector usable by fuel cells is strategic. It is possible to tackle the decarbonization of industrial chemical processes with the electrification of systems. The purpose of this review is to provide an overview of the latest research on the electrification of endothermic industrial chemical processes aimed at the production of H2 from methane and its use for energy production through proton exchange membrane fuel cells (PEMFC). In particular two main electrification methods are examined microwave heating (MW) and resistive heating (Joule) aimed at transferring heat directly on the surface of the catalyst. For cases the catalyst formulation and reactor configuration were analyzed and compared. The key aspects of the use of H2 through PEM were also analyzed highlighting the most used catalysts and their performance. With the information contained in this review we want to give scientists and researchers the opportunity to compare both in terms of reactor and energy efficiency the different solutions proposed for the electrification of chemical processes available in the recent literature. In particular through this review it is possible to identify the solutions that allow a possible scale-up of the electrified chemical process imagining a distributed production of hydrogen and its consequent use with PEMs. As for PEMs in the review it is possible to find interesting alternative solutions to platinum with the PGM (Platinum Group Metal) free-based catalysts proposing the use of Fe or Co for PEM application.
Macroeconomic Factors Influencing Public Policy Strategies for Blue and Green Hydrogen
Nov 2021
Publication
The aim of this paper is to analyze the factors affecting hydrogen and Carbon Capture and Storage Technologies (“CCS”) policies taking into consideration Fossil Fuel Consumption Oil Reserves the Debt/GDP Ratio the Trilemma Index and other variables with respect to OECD countries. STATA 17 was used for the analysis. The results confirm the hypothesis that countries with high fossil fuel consumption and oil reserves are investing in blue hydrogen and CCS towards a “zero-carbon-emission” perspective. Moreover countries with a good Debt/GDP ratio act most favorably to green policies by raising their Public Debt because Foreign Direct Investments are negatively correlated with those kinds of policies. Future research should exploit Green Finance policy decision criteria on green and blue hydrogen.
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