Publications

In this sixth episode Steffan Eldred Hydrogen Innovation Network Knowledge Transfer Manager and Debra Jones Chemistry Knowledge Transfer Manager from Innovate UK KTN discuss why converting waste to hydrogen is so important and explore the hydrogen transition opportunities and challenges in this sector alongside their special guest Rob Dent Senior Research Engineer - Energy Linde and Application Sales Engineer at BOC UK & Ireland.

The podcast can be found on their website.

On this episode of EAH we sat down with Alejandro Oyarce Barnett Chief Technology Officer and Co-Founder at Hystar. Hystar is a technology-focused company specializing in PEM electrolysers for hydrogen production using renewable energy. The company got its start as a spin-off from SINTEF one of Europe’s largest independent research organizations and has raised private funding so the company can focus on production of its high-efficiency PEM units and keep pace with demand for hydrogen generation capacity. Hystar announced on January 11 2023 that the company has closed a Series B funding round of USD 26mn to rapidly scale-up to full commercial operations with an automated GW-capacity production line by 2025.  Alejandro joined us to discuss in more detail the origins of Hystar its technology and the mission at the core of the company.

The podcast can be found on their website.

If Europe is to meet its 2050 decarbonisation objectives a change of paradigm needs to materialise. The energy sector cannot be understood any more as the sum of independent silos consisting of different energy vectors. Indeed a large number of technologies that are essential to meeting our decarbonisation targets are linking systems and markets currently being planned and operated without fully considering the potential benefits of adopting a holistic approach. If this situation is to persist large-scale sub-optimalities are likely to emerge if the planning and operations of the different components of the energy system will not be able to capture synergies and interdependencies between energy vectors and markets. Interlinkages between systems are appearing between all vectors both at the planning and operation levels. In the case of hydrogen these links are especially important as hydrogen technologies are linking the electricity methane and heat sectors (via electrolysis and hydrogen turbines repurposing of gas assets and hydrogen boilers respectively). Sector integration can allow to capture benefits both in terms of planning and operations:- The production of electrolytic hydrogen poses important challenges in terms of planning the deployment of renewable energy (RES) and electrolyser capacities in a way that ensures that the overall carbon emissions decrease in an effective and cost-efficient manner. Furthermore key questions related to the benefits of co-locating renewable capacities electrolysers and hydrogen demand centres can only be explored if a holistic perspective is adopted. Finally synergies can also appear if planning decisions are taken jointly between the electricity hydrogen and methane sectors as the optimal set of hydrogen infrastructure projects strongly depends on the ability to source electrolysers (link with the electricity sector) and on the possibility to repurpose part of the current infrastructure (link with the methane sector)- Similarly operational considerations also advocate for an integrated approach as electrolysers can provide important flexibility services to the electricity sector if provided with appropriate price signals. These considerations provide the motivation for this study which aims at performing a detailed examination of planning decisions and operational management of a 2050 power system with a focus on comparing different decarbonisation options for the provision of heat of different temperature levels.

This research work is the novel state-of-the-art technology performed on multi-cylinder SI engine fueled compressed natural gas emulsified fuel and hydrogen as dual fuel. This work predicts the overall features of performance combustion and exhaust emissions of individual fuels based on AVL Boost simulation technology. Three types of alternative fuels have been compared and analyzed. The results show that hydrogen produces 20% more brake power than CNG and 25% more power than micro-emulsion fuel at 1500 r/min which further increases the brake power of hydrogen CNG and micro-emulsions in the range of 25% 20% and 15% at higher engine speeds of 2500–4000 r/min respectively. In addition the brake-specific fuel consumption is the lowest for 100% hydrogen followed by CNG 100% and then micro-emulsions at 1500 r/min. At 2500– 5000 r/min there is a significant drop in brake-specific fuel consumption due to a lean mixture at higher engine speeds. The CO HC and NOx emissions significantly improve for hydrogen CNG and micro-emulsion fuel. Hydrogen fuel shows zero CO and HC emissions and is the main objective of this research to produce 0% carbon-based emissions with a slight increase in NOx emissions and CNG shows 30% lower CO emissions than micro-emulsions and 21.5% less hydrocarbon emissions than micro-emulsion fuel at stoichiometric air/fuel ratio.

This work relates the study of system performance in operational conditions for an isolated micro-grid powered by a photovoltaic system and a wind turbine. The electricity produced and not used by the user will be accumulated in two different storage systems: a battery bank and a hydrogen storage system composed of two PEM electrolyzers four pressurized tanks and a PEM fuel cell. One of the main problems to be solved in the development of isolated micro-grids is the management of the various devices and energy flows to optimize their functioning in particular in relation to the load profile and power produced by renewable energy systems depending on weather conditions. For this reason through the development and implementation of a specific simulation program three different energy management systems were studied to evaluate the best strategy for effectively satisfying user requirements and optimizing overall system efficiency.

Aiming at the synergy between a system’s carbon emission reduction demand and the economy of peak shaving operation in the process of optimizing the flexible resource peaking unit portfolio of a multi-energy power system containing large-scale electric vehicles this paper proposes a low-carbon optimal scheduling model for peak shaving resources in multi-energy power systems considering large-scale access for electric vehicles. Firstly the charging and discharging characteristics of electric vehicles were studied and a comprehensive cost model for electric vehicles heat storage and hydrogen storage was established. At the same time the carbon emission characteristics of multienergy power systems and their emission cost models under specific carbon trading mechanisms were established. Secondly the change characteristics of the system’s carbon emissions were studied and a carbon emission cost model of multi-energy power was established considering the carbon emission reduction demand of the system. Then taking the carbon emission of the system and the peak regulating operation costs of traditional units energy storage and new energy unit as optimization objectives the multi-energy power system peak regulation multi-objective optimization scheduling model was established and NSGA-II was used to solve the scheduling model. Finally based on a regional power grid data in Northeast China the improved IEEE 30 node multi-energy power system peak shaving simulation model was built and the simulation analysis verified the feasibility of the optimal scheduling model proposed in this paper.

Hydrogen is a key enabler of a sustainable society. Refurbishment of the existing natural gas infrastructure for up to 100% H2 is considered one of the most energy- and resource-efficient energy transportation methods. The question remains whether the transportation of 100% H2 with reasonable adaptions of the infrastructure and comparable energy amounts to natural gas is possible. The well-known critical components for refurbishment such as increased compressor power reduced linepack as well as pipeline transport efficiencies and their influencing factors were considered based on thermodynamic calculations with a step-by-step overview. A H2 content of 20–30% results in comparable operation parameters to pure natural gas. In addition to transport in pipelines decentralized H2 production will also play an important role in addressing future demands.

Land available for energy production is limited in cities owing to high population density. To reach the net zero goal cities contributing 70% of overall greenhouse gas emissions need to dramatically reduce emissions and increase self-sufficiency in energy production. Environmental infrastructures such as sewage treatment and incineration plants can be used as energy production facilities in cities. This study attempted to examine the effect of using environmental infrastructure such as energy production facilities to contribute toward the carbon neutrality goal through urban energy systems. In particular since the facilities are suitable for hydrogen supply in cities the analysis was conducted focusing on the possibility of hydrogen production. First the current status of energy supply and demand and additional energy production potential in sewage treatment and incineration plants in Seoul were analyzed. Then the role of these environmental infrastructures toward energy self-sufficiency in the urban system was examined. This study confirmed that the facilities can contribute to the city’s energy self-sufficiency and the achievement of its net-zero goal.

The optimal design of off-grid hybrid renewable energy systems (HRESs) is a challenging task which often involves conflicting goals to be faced. In this work levelized cost of energy (LCOE) and CO2 emissions have been addressed simultaneously by using the ε-constraint method together with the particle swarm optimization (PSO) algorithm. Cost-emissions Pareto fronts of different HRES configurations were developed to gain greater awareness about the potential of renewable-based energy systems in off-grid applications. Various combinations of the following components were investigated: photovoltaic panels wind turbines batteries hydrogen and diesel generators. The hydrogen-based system comprises an electrolyzer to convert the excess renewable energy into hydrogen a pressurized tank for H2 storage and a fuel cell for the reconversion of hydrogen into electricity during renewable energy deficits. Electrolyzer and fuel cell devices were modelled by means of part-load performance curves. Size-dependent costs and component lifetimes as a function of the cumulative operational duty were also considered for a more accurate techno-economic assessment. The proposed methodology was applied to the Froan islands (Norway) which were chosen as a reference case study since they are well representative of many other insular microgrid environments in Northern Europe. Results from the sizing simulations revealed that energy storage devices are key components to reduce the dependency on fossil fuels. In particular the hydrogen storage system is crucial in off-grid areas to enhance the RES penetration and avoid a sharp increase in the cost of energy. Hydrogen in fact allows the battery and RES technologies not to be oversized thanks to its cost-effective long-term storage capability. Concerning the extreme case with no diesel the cheapest configuration which includes both batteries and hydrogen has an LCOE of 0.41 €/kWh. This value is around 35% lower than the LCOE of a system with only batteries as energy storage.

This paper aims to expose the effect of hydrogen on the combustion performance and emissions of a high-speed diesel engine. For this purpose a three-dimensional dynamic simulation model was developed using a reasonable turbulence model and a simplified reaction kinetic mechanism was chosen based on experimental data. The results show that in the hydrogen enrichment conditions hydrogen causes complete combustion of diesel fuel and results in a 17.7% increase in work capacity. However the increase in combustion temperature resulted in higher NOx emissions. In the hydrogen substitution condition the combustion phases are significantly earlier with the increased hydrogen substitution ratio () which is not conducive to power output. However when the is 30% the CO soot and THC reach near-zero emissions. The effect of the injection timing is also studied at an HSR of 90%. When delayed by 10° IMEP improves by 3.4% compared with diesel mode and 2.4% compared with dual-fuel mode. The NOx is reduced by 53% compared with the original dual-fuel mode. This study provides theoretical guidance for the application of hydrogen in rail transportation.