Publications

Background: The widespread use of sustainable energy technologies is a key element in the transformation of the energy system from fossil-based to zero-carbon. In line with this technology acceptance is of great importance as resistance from the public can slow down or hinder the construction of energy technology projects. The current study assesses the social acceptance of three energy technologies relevant for the German energy transition: stationary battery storage biofuel production plants and hydrogen fuel station. Methods: An online survey was conducted to examine the public’s general and local acceptance of energy technologies. Explored factors included general and local acceptance public concerns trust in relevant stakeholders and attitudes towards financial support. Results: The results indicate that general acceptance for all technologies is slightly higher than local acceptance. In addition we discuss which public concerns exist with regard to the respective technologies and how they are more strongly associated with local than general acceptance. Further we show that trust in stakeholders and attitudes towards fnancial support is relatively high across the technologies discussed. Conclusions: Taken together the study provides evidence for the existence of a “general–local” gap despite measuring general and local acceptance at the same level of specifcity using a public sample. In addition the collected data can provide stakeholders with an overview of worries that might need to be addressed when planning to implement a certain energy project.

The environment is seriously threatened by the rising energy demand and the use of conventional energy sources. Renewable energy sources including hydro solar and wind have been the focus of extensive research due to the proliferation of energy demands and technological advancement. Wind energy is mostly harvested in coastal areas and little work has been done on energy extraction from winds in a suburban environment. The fickle behavior of wind makes it a less attractive renewable energy source. However an energy storage method may be added to store harvested wind energy. The purpose of this study is to evaluate the feasibility of extracting wind energy in terms of hydrogen energy in a suburban environment incorporating artificial intelligence techniques. To this end a site was selected latitude 33.64◦ N longitude 72.98◦ N and elevation 500 m above mean sea level in proximity to hills. One year of wind data consisting of wind speed wind direction and wind gust was collected at 10 min intervals. Subsequently long short-term memory (LSTM) support vector regression (SVR) and linear regression models were trained on the empirically collected data to estimate daily hydrogen production. The results reveal that the overall prediction performance of LSTM was best compared to that of SVR and linear regression models. Furthermore we found that an average of 6.76 kg/day of hydrogen can be produced by a 1.5 MW wind turbine with the help of an artificial intelligence method (LSTM) that is well suited for time-series data to classify process and predict.

The modelling underpinning the scenarios for the EU long-term strategy did not include hydrogen trade. The assumption was that each Member State (MS) supplies its own needs for hydrogen and synthetic fuels. The goal of this study is to develop a model to undertake optimal geolocation of hydrogen production between MS including the possibility to trade hydrogen and therefore use the RES potential more optimally and decrease energy system costs at EU level. Specifically the new model helps to identify the geo-location of: 1. Renewable energy production (PV wind biomass hydro) 2. Location of RES and hydrogen production facilities 3. Storage infrastructure also for natural gas and storage technologies i.e. batteries pumping etc. 4. Infrastructure by road and pipeline

Operators of public electricity grids today are faced with the challenge of integrating increasing numbers of renewable and decentralized energy sources such as wind turbines and photovoltaic power plants into their grids. These sources produce electricity in a very inconstant manner due to the volatility of wind and solar power which further complicates power grid control and management. One key component that is required for modern energy infrastructures is the capacity to store large amounts of energy in an economically feasible way.<br/>One solution that is being discussed in this context is “power-to-gas” i.e. the use of surplus electricity to produce hydrogen (or even methane with an additional methanation process) which is then injected into the public natural gas grid. The huge storage capacity of the gas grid would serve as a buffer offering benefits with regards to sustainability and climate protection while also being cost-effective since the required infrastructure is already in place.<br/>One consequence would be however that the distributed natural gas could contain larger and fluctuating amounts of hydrogen. There is some uncertainty how different gas-fired applications and processes react to these changes. While there have already been several investigations for domestic appliances (generally finding that moderate amounts of H2 do not pose any safety risks which is the primary focus of domestic gas utilization) there are still open questions concerning large-scale industrial gas utilization. Here in addition to operational safety factors like efficiency pollutant emissions (NOX) process stability and of course product quality have to be taken into account.<br/>In a German research project Gas- und Wärme-Institut Essen e. V. (GWI) investigated the impact of higher and fluctuating hydrogen contents (up to 50 vol.-% much higher than what is currently envisioned) on a variety of industrial combustion systems using both numerical and experimental methods. The effects on operational aspects such as combustion behavior flame monitoring and pollutant emissions were analyzed.<br/>Some results of these investigations will be presented in this contribution.

Hydrogen supplementation in diesel Compression Ignition (CI) engines is gaining more attention since it is considered as a feasible solution to tackle the challenges that are related to the emission regulations that will be applied in the forthcoming years. Such a solution is very attractive because it requires only limited modifications to the existing technology of internal combustion CI engines. To this end numerous work on the investigation of an engine’s performance and the effects of emissions when hydrogen is supplied in the engine’s cylinders has been completed by researchers. However contradictory results were found among these studies regarding the efficiency of the engine and the emission characteristics achieved compared to the diesel-only operation. The different conclusions might be attributed to the different characteristics and technology level of the engines that were utilized as well as on the chosen operational parameters. This paper aims to present an overview of the experimental studies that have examined the effects of hydrogen addition in CI four-stroke diesel engines reporting the characteristics of the utilized engines the quantities of hydrogen tested the method of hydrogen induction used as well as the operational conditions tested in order to help interested researchers to easily identify relevant and appropriate studies to perform comparisons or validations by repeating certain cases. The presented data do not include any results or conclusions from these studies. Furthermore an experimental configuration along with the appropriate modifications on a heavy-duty auxiliary generator-set engine that was recently developed by the authors for the purposes of the HYMAR project is presented.

The interest in hybrid polymer electrolyte membrane fuel cells (PEMFC) fuelled by hydrogen in shipping has seen an unprecedented growth in the last years as it could allow zero-emission navigation. However technical safety and regulatory barriers in PEMFC ship design and operation are hampering the use of such systems on a large scale. While several studies analyse these aspects a comprehensive and up-to-date overview on hydrogen PEMFCs for shipping is missing. Starting from the survey of past/ongoing projects on FCs in shipping this paper presents an extensive review on maritime hydrogen PEMFCs outlining the state of the art and future trends for hydrogen storage and bunkering powertrain and regulations. In addition to the need for a clear regulatory framework future studies should investigate the development of an efficient fuel supply chain and bunkering facilities ashore. As for the onboard power system health-conscious energy management low-temperature heat recovery and advancements in fuel processing have emerged as hot research topics.

Steam natural gas reforming is the preferred technique presently used to produce hydrogen. Proposed in 1932 the technique is very well established but still subjected to perfections. Herein first the improvements being sought in catalysts and processes are reviewed and then the advantage of replacing the energy supply from burning fuels with concentrated solar energy is discussed. It is especially this advance that may drastically reduce the economic and environmental cost of hydrogen production. Steam reforming can be easily integrated into concentrated solar with thermal storage for continuous hydrogen production.

Hydrogen produced from renewable energy sources is clean and sustainable. Biomass gasification has a significant role in the context of hydrogen generation from biomass. Assessment of the performance of biomass gasification process regarding the product gas yield and composition can be performed using mathematical models. Among the different mathematical models thermodynamic equilibrium models are simple and useful tools for the first estimate and preliminary comparison and assessment of gasification process. A stoichiometric thermodynamic equilibrium model is developed here and its performance is validated for steam gasification and air-steam gasification. The model is then used to assess the feasibility of different biomass feedstock for gasification based on hydrogen yield and lower heating value.

With rising temperatures extreme weather events and environmental challenges there is a strong push towards decarbonization and an emphasis on renewable energy with wind energy emerging as a key player. The concept of multi-energy systems offers an innovative approach to decarbonization with the potential to produce hydrogen as one of the output streams creating another avenue for clean energy production. Hydrogen has significant potential for decarbonizing multiple sectors across buildings transport and industries. This paper explores the integration of wind energy and hydrogen production particularly in areas where clean energy solutions are crucial such as impoverished villages in Africa. It models three systems: distinct configurations of micro-multi-energy systems that generate electricity space cooling hot water and hydrogen using the thermodynamics and cost approach. System 1 combines a wind turbine a hydrogen-producing electrolyzer and a heat pump for cooling and hot water. System 2 integrates this with a biomass-fired reheat-regenerative power cycle to balance out the intermittency of wind power. System 3 incorporates hydrogen production a solid oxide fuel cell for continuous electricity production an absorption cooling system for refrigeration and a heat exchanger for hot water production. These systems are modeled with Engineering Equation Solver and analyzed based on energy and exergy efficiencies and on economic metrics like levelized cost of electricity (LCOE) cooling (LCOC) refrigeration (LCOR) and hydrogen (LCOH) under steady-state conditions. A sensitivity analysis of various parameters is presented to assess the change in performance. Systems were optimized using a multiobjective method with maximizing exergy efficiency and minimizing total product unit cost used as objective functions. The results show that System 1 achieves 79.78 % energy efficiency and 53.94 % exergy efficiency. System 2 achieves efficiencies of 55.26 % and 27.05 % respectively while System 3 attains 78.73 % and 58.51 % respectively. The levelized costs for micro-multi-energy System 1 are LCOE = 0.04993 $/kWh LCOC = 0.004722 $/kWh and LCOH = 0.03328 $/kWh. For System 2 these values are 0.03653 $/kWh 0.003743 $/kWh and 0.03328 $/kWh. In the case of System 3 they are 0.03736 $/kWh 0.004726 $/kWh and 0.03335 $/kWh and LCOR = 0.03309 $/kWh. The results show that the systems modeled here have competitive performance with existing multi-energy systems powered by other renewables. Integrating these systems will further the sustainable and net zero energy system transition especially in rural communities.

Transportation is one of the largest sources of CO2 emissions accounting for more than 20% of worldwide emissions. However it is one of the areas where decarbonization presents the greatest hurdles owing to its capillarity and the benefits that are associated with the use of fossil fuels in terms of energy density storage and transportation. In order to accomplish comprehensive decarbonization in the transport sector it will be required to encourage a genuine transition to low-carbon fuels and the widespread deployment of the necessary infrastructures to allow for a large-scale innovation. Renewable hydrogen shows potential for sustainable transportation applications whether in fuel cell electric vehicles (FCEVs) such as automobiles trucks and trains or as a raw material for ship and airplane synthetic fuels. The present paper aims to present how hydrogen-fuel cell hybrid powertrains for road vehicles work in terms of conceptual layouts and operating strategies. A comprehensive overview of real and current applications is presented concerning existing prototypes and commercially available vehicles with a focus on the main key performance indicators such as efficiency mileage and energy consumption.

In recent decades governments and society have been making increasing efforts to address and mitigate climate change by reducing emissions and decarbonising energy generation. Ireland has invested greatly in renewable electricity installing 4 GW of wind capacity since 2002 and has set assertive energy targets such as the aim to reduce overall emissions by 51% by 2030. Nonetheless considerable acceleration is needed in the decarbonisation of the country’s energy sector. This paper investigates the potential role hydrogen can play in Ireland’s energy transition proposing hydrogen as an energy vector and storage medium that may help the country achieve its targets and reduce greenhouse gas emissions. Through literature review research and from industry insights the current state of the Irish energy sector is analysed and recommendations are made as to how where and when hydrogen can be integrated into the decarbonisation of Ireland’s electricity heating and transport. It is concluded that; with significant effort from the government policymakers industry and organisations; the effective deployment of hydrogen technologies in Ireland could avoid up to 6.1 MtCO2eq of emissions annually reflecting a trend observed in many other developed countries in which hydrogen plays an important part in the path to a low-carbon future. Prospective roles for hydrogen in Ireland include renewable energy storage and grid balancing through the deployment of Power-to-Gas systems a replacement for fossil natural gas in the gas grid for backup electricity production as well as industry and heating requirements and the use of hydrogen as a fuel for heavy transport.

With the constant increase in variable renewable energy production in electricity and district heating systems integration with the gas system is a way to provide flexibility to the overall energy system. In the sustainable transition towards a zero-emission energy system traditional natural gas can be substituted by renewable gasses derived from anaerobic digestion or thermal gasification and hydrogen. In this paper we present a methodology for modelling renewable gas options and limits on biomass resources across sectors in the energy optimisation model Balmorel. Different scenarios for socio-economic pathways to emission neutral electricity and district heating systems in Denmark Sweden Norway and Germany show that a renewable based energy system benefits from a certain percentage of gas as a supplement to other flexibility options like interconnectors. Especially upgraded biogas from anaerobic digestion serves as a substitute for natural gas in all scenarios. Allocating only 10% of available biomass to the electricity and district heating sector leads to full exploitation of the scarce biomass resource by boosting biogas and syngas with hydrogen. The need for renewable gasses is highest in Germany and least in Norway where hydro-power provides flexibility in terms of storable and dispatchable electricity production. The scenarios show that a required ‘‘late sprint" from fossils to achieve a zero-emission energy system in 2050 causes (1) significant higher accumulated emissions and (2) a system which strongly relies on fuels also in an emission free system instead of stronger integration of the electricity and district heating systems through electrification as well as stronger integration of the power systems across countries through interconnectors.

Renewable energy supply is essential for carbon neutrality; however technologies aiming to optimally utilize renewable energy sources remain insufficient. Seasonal variability in renewable energy is a key issue which many studies have attempted to overcome through operating systems and energy storage. Currently hydrogen is the only technology that can solve this seasonal storage problem. In this study the amount of hydrogen required to circumvent the seasonal variability in renewable energy supply in Korea was quantified. Spatiotemporal analysis was conducted using renewable energy resource maps and power loads. It was predicted that 50% of the total power demand in the future will be met using solar and wind power and a scenario was established based on the solar-to-wind ratio. It was found that the required hydrogen production differed by approximately four-times depending on the scenarios highlighting the importance of supplying renewable energy at an appropriate ratio. Spatially wind power was observed to be unsuitable for the physical transport of hydrogen because it has a high potential at mountain peaks and islands. The results of this study are expected to aid future hydrogen research and solve renewable energy variability problems.

In recent years there has been great interest in Wankel-type rotary engines which are one of the most suitable power sources for unmanned aerial vehicle (UAV) applications due to their high power-to-size and power-to-weight ratios. The purpose of the present study was to investigate the potential of a hydrogen enrichment strategy for the improvement of the performance and reduction of the emissions of Wankel engines. The main motivation behind this study was to make Wankel engines which are already very advantageous for UAV applications even more advantageous by applying the hydrogen enrichment technique. In this study hydrogen addition was implemented in a spark-ignition rotary engine model operating at a constant engine speed of 6000 rpm. The mass fraction of hydrogen in the intake gradually increased from 0% to 10%. Simulation results revealed that addition of hydrogen to the fuel accelerated the flame propagation and increased the burning speed of the fuel the combustion temperature and the peak pressure in the working chamber. These phenomena had a very positive effect on the performance and emissions of the Wankel engine. The indicated mean effective pressure (IMEP) increased by 8.18% and 9.68% and the indicated torque increased by 6.15% and 7.99% for the 5% and 10% hydrogen mass fraction cases respectively compared to those obtained with neat gasoline. In contrast CO emissions were reduced by 33.35% and 46.21% and soot emissions by 11.92% and 20.06% for 5% and 10% hydrogen additions respectively. NOx emissions increased with the application of the hydrogen enrichment strategy for the Wankel engine.

The use of green hydrogen as a fuel source for marine applications has the potential to significantly reduce the carbon footprint of the industry. The development of a sustainable and cost-effective method for producing green hydrogen has gained a lot of attention. Water electrolysis is the best and most environmentally friendly method for producing green hydrogen-based renewable energy. Therefore identifying the ideal operating parameters of the water electrolysis process is critical to hydrogen production. Three controlling factors must be appropriately identified to boost hydrogen generation namely electrolysis time (min) electric voltage (V) and catalyst amount (µg). The proposed methodology contains the following two phases: modeling and optimization. Initially a robust model of the water electrolysis process in terms of controlling factors was established using an adaptive neuro-fuzzy inference system (ANFIS) based on the experimental dataset. After that a modern pelican optimization algorithm (POA) was employed to identify the ideal parameters of electrolysis duration electric voltage and catalyst amount to enhance hydrogen production. Compared to the measured datasets and response surface methodology (RSM) the integration of ANFIS and POA improved the generated hydrogen by around 1.3% and 1.7% respectively. Overall this study highlights the potential of ANFIS modeling and optimal parameter identification in optimizing the performance of solar-powered water electrocatalysis systems for green hydrogen production in marine applications. This research could pave the way for the more widespread adoption of this technology in the marine industry which would help to reduce the industry’s carbon footprint and promote sustainability.

This study established global warming potential(GWP) emission factors through a life cycle assessment on the operation phases of two different 1 kW polymer electrolyte membrane fuel cell (PEMFC) systems for residential buildings (NG-PEMFC fed with hydrogen from natural gas reforming; WE-PEMFC fed with hydrogen from photovoltaics-powered water electrolyzer). Their effectiveness was also compared with conventional power grid systems in Korea specifically in the area of greenhouse gas emissions. The operation phases of the NG-PEMFC and the WE-PEMFC were divided into burner reformer and stack and into water electrolysis and stack respectively. The functional unit of each fuel cell system was defined as 1 kWh of electricity production. In the case of NG-PEMFC the GWP was 3.72E-01 kg-CO2eq/kWh the embodied carbon emissions due to using city gas during the life cycle process was about 20.87 % the carbon emission ratio according to the reformer's combustion burner was 6.07 % and the direct carbon emission ratio of the air emissions from the reformer was 73.06 % indicating that the carbon emission from the reformer contributed over 80 % of the total GWP. As for the WE-PEMFC the GWP was 1.76E-01 kg-CO2eq/kWh and the embodied carbon emissions from photovoltaic power generation during the life cycle process contributed over 99 % of the total GWP.

In this episode titled "The Commission's support to the hydrogen ecosystem" our CEO Jorgo Chatzimarkakis discusses with Rosalinde van der Vlies Clean Planet Director DG RTD - European Commission. Starting off on how Rosalinde joined the Commission the two speakers discuss the Commission's support in developing a hydrogen ecosystem also in light of its participation in the Clean Hydrogen Partnership and the implications arising from the REPowerEU.

The use of autonomous vehicles for marine and submarine work has risen considerably in the last decade. Developing new monitoring systems navigation and communications technologies allows a wide range of operational possibilities. Autonomous Underwater Vehicles (AUVs) are being used in offshore missions and applications with some innovative purposes by using sustainable and green energy sources. This paper considers an AUV that uses a hydrogen fuel cell achieving zero emissions. This paper analyses the life cycle cost of the UAV and compares it with a UAV powered by conventional energy. The EN 60300-3-3 guidelines have been employed to develop the cost models. The output results show estimations for the net present value under different scenarios and financial strategies. The study has been completed with the discount rate sensibility analysis in terms of financial viability.

Debra Jones Chemistry Knowledge Transfer Manager and Simon Buckley Zero Emission Mobility Knowledge Transfer Manager from Innovate UK KTN talk about green hydrogen production with their special guest  Chris Jackson CEO & Founder at Protium.

This podcast discussion centres around methods of producing clean hydrogen from renewable energy sources the innovative projects Protium is working on and how much green hydrogen will the UK produce by 2030 and beyond.

The podcast can be found on their website.

Decarbonisation will need a significant societal shift. The when why and how we travel is going to look very different within a decade. Joining us is Florentine Roy – a leading expert on electric vehicles and Innovation Project Lead at UK Power Networks and Matt Hindle - Head of Net Zero and Sustainability at Wales and West Utilities. Let’s talk about the energy system implications of this massive undertaking and how it can be enabled by innovation in a fair and just way.

The podcast can be found here.

Clean technologies play a crucial role in reducing greenhouse gas emissions and protecting the climate. Hydrogen is a promising energy carrier and fuel that can be used in many applications. We explore the global hydrogen technological innovation system (TIS) by analyzing the three knowledge and technology transfer channels of publications patents and standards. Since the adoption of hydrogen technologies requires trust in their safety this study specifically also focuses on hydrogen safety. Our results show that general and hydrogen safety research has increased significantly while patenting experienced stagnation. An analysis of the non-patent literature in safety patents shows little recognition of scientific publications. Similarly publications are under-represented in the analyzed 75 international hydrogen and fuel cell standards. This limited transfer of knowledge from published research to standards points to the necessity for greater involvement of researchers in standardization. We further derive implications for the hydrogen TIS and recommendations for a better and more impactful alignment of the three transfer channels.

In this episode of the podcast Debra Jones Chemistry Knowledge Transfer Manager and Ray Chegwin Nuclear Knowledge Transfer Manager from Innovate UK KTN talk about nuclear uses for hydrogen with special guest Allan Simpson Technical Lead at the National Nuclear Laboratory.

The podcast can be found on their website.

The use of hydrogen as a non-emission energy carrier is important for the innovative development of the power-generation industry. Transmission pipelines are the most efficient and economic method of transporting large quantities of hydrogen in a number of variants. A comprehensive hydraulic analysis of hydrogen transmission at a mass flow rate of 0.3 to 3.0 kg/s (volume flow rates from 12000 Nm3/h to 120000 Nm3/h) was performed. The methodology was based on flow simulation in a pipeline for assumed boundary conditions as well as modeling of fluid thermodynamic parameters for pure hydrogen and its mixtures with methane. The assumed outlet pressure was 24 bar (g). The pipeline diameter and required inlet pressure were calculated for these parameters. The change in temperature was analyzed as a function of the pipeline length for a given real heat transfer model; the assumed temperatures were 5 and 25 ◦C. The impact of hydrogen on natural gas transmission is another important issue. The performed analysis revealed that the maximum participation of hydrogen in natural gas should not exceed 15%–20% or it has a negative impact on natural gas quality. In the case of a mixture of 85% methane and 15% hydrogen the required outlet pressure is 10% lower than for pure methane. The obtained results present various possibilities of pipeline transmission of hydrogen at large distances. Moreover the changes in basic thermodynamic parameters have been presented as a function of pipeline length for the adopted assumptions.

Hydrogen production from natural gas combined with advanced CO2 capture technologies such as iron-based chemical looping (CL) is considered in the present work. The processes are compared to the conventional base case i.e. hydrogen production via natural gas steam reforming (SR) without CO2 capture. The processes are simulated using commercial software (ChemCAD) and evaluated from a technical point of view considering important key performance indicators such as hydrogen thermal output net electric power carbon capture rate and specific CO2 emissions. The environmental evaluation is performed using Life Cycle Analysis (LCA) with the following system boundaries considered: i) hydrogen production from natural gas coupled to CO2 capture technologies based on CL ii) upstream processes such as: extraction and processing of natural gas ilmenite and catalyst production and iii) downstream processes such as: H2 and CO2 compression transport and storage. The LCA assessment was carried out using the GaBi6 software. Different environmental impact categories following here the CML 2001 impact assessment method were calculated and used to determine the most suitable technology. Sensitivity analyses of the CO2 compression transport and storage stages were performed in order to examine their effect on the environmental impact categories.

In recent years growing awareness about environmental issues is pushing humankind to explore innovative technologies to reduce the anthropogenic sources of pollutants. Among these sources internal combustion engines in non-road mobile machinery (NRMM) such as agricultural tractors are one of the most important. The aim of this work is to explore the possibility of replacing the conventional diesel engine with an electric powertrain powered by a hybrid storage system consisting of a small battery pack and a fuel-cell system. The battery pack (BP) is necessary to help the fuel cell manage sudden peaks in power demands. Numerical models of the conventional powertrain and a fuel-cell tractor were carried out. To compare the two powertrains work cycles derived from data collected during real operative conditions were exploited and simulated. For the fuel-cell tractor a control strategy to split the electric power between the battery pack and the fuel cell was explored. The powertrains were compared in terms of greenhouse gas emissions (GHG) according to well-to-wheel (WTW) equivalent CO2 emission factors available in the literature. Considering the actual state-of-the-art hydrogen production methods the simulation results showed that the fuel-cell/battery powertrain was able to accomplish the tasks with a reduction of about 50% of the equivalent CO2 emissions compared to traditional diesel-powered vehicles.