Publications

In this study the optimal sizing of a hybrid battery/hydrogen Energy Storage System “ESS” is assessed via a model-based parametric analysis in the context of a real hybrid renewable microgrid located in Huelva Spain supplying a real-time monitored residential load (3.5 kW; 5.6 MWh/year) in island mode. Four storage configurations (battery-only H2-only hybrid battery priority and hybrid H2 priority) are assessed under different Energy Management Strategies analysing system performance parameters such as Loss of Load “LL” (kWh;%) Over Production “OP” (kWh;%) round-trip storage efficiency ESS (%) and total storage cost (€) depending on the ESS sizing characteristics. A parallel approach to the storage optimal sizing via both multi-dimensional sensitivity analysis and PSO is carried out in order to address both sub-optimal and optimal regions respectively. Results show that a hybridised ESS capacity is beneficial from an energy security and efficiency point of view but can represent a substantial additional total cost (between 100 and 300 k€) to the hybrid energy system especially for the H2 ESS which presents higher costs. Reaching 100% supply from renewables is challenging and introducing a LL threshold induces a substantial relaxation of the sizing and cost requirements. Increase in battery capacity is more beneficial for the LL abatement while increasing H2 capacity is more useful to absorb large quantities of excess energy. The optimal design via PSO technique is complemented to the parametric study.

Rapid industrial development vehicles domestic activities and mishandling of garbage are the main sources of pollutants which are destroying the atmosphere. There is a need to continuously monitor these pollutants for the safety of the environment and human beings. Conventional instruments for monitoring of toxic gases are expensive bigger in size and time-consuming. Hybrid materials containing organic and inorganic components are considered potential candidates for diverse applications including gas sensing. Gas sensors convert the information regarding the analyte into signals. Various polymeric/inorganic nanohybrids have been used for the sensing of toxic gases. Composites of different polymeric materials like polyaniline (PANI) poly (4-styrene sulfonate) (PSS) poly (34-ethylene dioxythiophene) (PEDOT) etc. with various metal/metal oxide nanoparticles have been reported as sensing materials for gas sensors because of their unique redox features conductivity and facile operation at room temperature. Polymeric nanohybrids showed better performance because of the larger surface area of nanohybrids and the synergistic effect between polymeric and inorganic materials. This review article focuses on the recent developments of emerging polymeric/inorganic nanohybrids for sensing various toxic gases including ammonia hydrogen nitrogen dioxide carbon oxides and liquefied petroleum gas. Advantages disadvantages operating conditions and prospects of hybrid composites have also been discussed.

Gas pipelines are exposed to operational loads combined with corrosive environment action during their long-term service. Complicated service conditions lead to a worsening of steel properties a reduction of serviceability of the whole object therefore a risk of its premature failure rises. Aware of the importance of the existing problem the aim of this study is the analysis of various mechanical properties of steels after their long-term operation on gas pipelines and detecting and evaluating fractographic signs of this degradation.<br/>Mechanical properties of operated pipe steels characterizing their brittle fracture resistance were significantly decreased. Delamination areas as one of a feature of brittle fracture were identified on the fracture surfaces of specimens after SSRT of the operated steels in corrosive environment. Fracture was initiated from the outer surface of the specimens along the boundaries of ferrite and pearlite grains with significant secondary cracking.<br/>The obvious texture in the steels affects noticeably the results of the impact tests. Higher KCV values for the specimens cut in the longitudinal direction relative to the pipe axis comparing with the specimens of transversal orientation were obtained. This was explained by different length of narrow pearlite strips alternated by wide ferrite bands and interrupted by individual ferrite grains depending on the orientation of the specimen fracture surface relative to the pipe axis. Thus a proper direction of specimen cutting to achieve the maximum sensitivity of KCV parameter to operational degradation of steels is discussed. The effect of specimen orientation on the results of the Charpy testing becomes much more pronounced with steel operation. Defects accumulated in steels during their service are preferentially oriented in the pipe axial direction along the boundaries between ferrite and pearlite strips. Analyzing the fracture surfaces of the Charpy specimens after their impact testing certain signs of embrittlement were found for long term operated steels in the form of delaminations varying in size and shape and some cleavage fragments. Furthermore their percentage of total fracture surface (generally formed by dimples) correlates well with a drop in the impact toughness. The established relationship could be the basis for the introduction of fractographic criteria of the steel serviceability.

Automotive proton-exchange membrane fuel cells (PEMFCs) have finally reached a state of technological readiness where several major automotive companies are commercially leasing and selling fuel cell electric vehicles including Toyota Honda and Hyundai. These now claim vehicle speed and acceleration refueling time driving range and durability that rival conventional internal combustion engines and in most cases outperform battery electric vehicles. The residual challenges and areas of improvement which remain for PEMFCs are performance at high current density durability and cost. These are expected to be resolved over the coming decade while hydrogen infrastructure needs to become widely available. Here we briefly discuss the status of automotive PEMFCs misconceptions about the barriers that platinum usage creates and the remaining hurdles for the technology to become broadly accepted and implemented.

Renewable energy is considered the one of the most promising solutions to meet sustainable development goals in terms of climate change mitigation. Today we face the problem of further scaling up renewable energy infrastructure which requires the creation of reliable energy storages environmentally friendly carriers like hydrogen and competitive international markets. These issues provoke the involvement of resource-based countries in the energy transition which is questionable in terms of economic efficiency compared to conventional hydrocarbon resources. To shed a light on the possible efficiency of green hydrogen production in such countries this study is aimed at: (1) comparing key Russian trends of green hydrogen development with global trends (2) presenting strategic scenarios for the Russian energy sector development (3) presenting a case study of Russian hydrogen energy project «Dyakov Ust-Srednekanskaya HPP» in Magadan region. We argue that without significant changes in strategic planning and without focus on sustainable solutions support the further development of Russian power industry will be halted in a conservative scenario with the limited presence of innovative solutions in renewable energy industries. Our case study showed that despite the closeness to Japan hydrogen market economic efficiency is on the edge of zero with payback period around 17 years. The decrease in project capacity below 543.6 MW will immediately lead to a negative NPV. The key reason for that is the low average market price of hydrogen ($14/kg) which is only a bit higher than its production cost ($12.5/kg) while transportation requires about $0.96/kg more. Despite the discouraging results it should be taken into account that such strategic projects are at the edge of energy development. We see them as an opportunity to lead transnational energy trade of green hydrogen which could be competitive in the medium term especially with state support.

Two electrolysis technologies fed with renewable energy sources are promising for the production of CO₂-free hydrogen and enabling the transition to a hydrogen society: Alkaline Electrolyte (AE) and Polymer Electrolyte Membrane (PEM). However limited information exists on the potential environmental impacts of these promising sustainable innovations when operating on a large-scale. To fill this gap the performance of AE and PEM systems is compared using ex-ante Life Cycle Assessment (LCA) technology analysis and exploratory scenarios for which a refined methodology has been developed to study the effects of implementing large-scale sustainable hydrogen production systems. Ex-ante LCA allows modelling the environmental impacts of hydrogen production exploratory scenario analysis allows modelling possible upscaling effects at potential future states of hydrogen production and use in vehicles in the Netherlands in 2050. A bridging tool for mapping the technological field has been created enabling the combination of quantitative LCAs with qualitative scenarios. This tool also enables diversity for exploring multiple sets of visions. The main results from the paper show with an exception for the “ozone depletion” impact category (1) that large-scale AE and PEM systems have similar environmental impacts with variations lower than 7% in all impact categories (2) that the contribution of the electrolyser is limited to 10% of all impact categories results and (3) that the origin of the electricity is the largest contributor to the environmental impact contributing to more than 90% in all impact categories even when renewable energy sources are used. It is concluded that the methodology was applied successfully and provides a solid basis for an ex-ante assessment framework that can be applied to emerging technological systems.

The information in this report covers the period January 2019 – December 2019. The technology and market module of the FCHO presents a range of statistical data as an indicator of the health of the sector and the progress in market development over time. This includes statistical information on the size of the global fuel cell market including number and capacity of fuel cell systems shipped in a calendar year. For this first edition data to the end of 2019 is presented where possible alongside analysis of key sector developments. Fuel cell system shipments for each calendar year are presented both as numbers of units and total system megawatts. The data are further divided and subdivided by: • Application: Total system shipments are divided into Transport Stationary and Portable applications • Fuel cell type: Numbers are provided for each of the different fuel cell chemistry types • Region of integration: Region where the final manufacturer – usually the system integrator – integrates the fuel cell into the final product • Region of deployment: Region where the final product was shipped to for deployment The data is sourced directly from industry players as well as other relevant sources including press releases associations and other industry bodies.

Hybrid photovoltaic–regenerative hydrogen fuel cell (PV-RHFC) microgrid systems are considered to have a high future potential in the effort to increase the renewable energy share in the form of solar PV technology with hydrogen generation storage and reutilization. The current study provides a comprehensive review of the recent research progress of hybrid PV-RHFC microgrid systems to extract conclusions on their characteristics and future prospects. The different components that can be integrated (PV modules electrolyzer and fuel cell stacks energy storage units power electronics and controllers) are analyzed in terms of available technology options. The main modeling and optimization methods and control strategies are discussed. Additionally various application options are provided which differentiate in terms of scale purpose and further integration with other power generating and energy storage technologies. Finally critical analysis and discussion of hybrid PV-RHFC microgrid systems were conducted based on their current status. Overall the commercialization of hybrid PV-RHFC microgrid systems requires a significant drop in the RHFC subsystem capital cost. In addition it will be necessary to produce complete hybrid PV-RHFC microgrid systems with integrated energy management control capabilities to avoid operational issues and ensure flexibility and reliability of the energy flow in relation to supply storage and demand.

Achieving climate-neutrality requires considerable investment in energy storage systems (ESS) to integrate variable renewable energy sources into the grid. However investments into ESS are often unprofitable in particular for grid-scale battery storage and green hydrogen technologies prompting many actors to call for policy intervention. This study investigates investor-specific risk-return preferences for ESS investment and derives policy recommendations. Insights are drawn from 1605 experimental investment-related decisions obtained from 42 high-level institutional investors and utility representatives. Results reveal that both investor groups view revenue stacking as key to making ESS investment viable. While the expected return on investment is the most important project characteristic risk-return preferences for other features diverge between groups. Institutional investors appear more open to exploring new technological ventures (20% of utility respondents would not consider making investments into solar photovoltaic-hydrogen) whereas utilities seem to prefer greenfield projects (23% of surveyed institutional investors rejected such projects). Interestingly both groups show strong aversion towards energy market price risk. Institutional investors require a premium of 6.87 percentage points and utilities 5.54 percentage points for moving from a position of fully hedged against market price risk to a scenario where only 20% of revenue is fixed underlining the need for policy support.

In this present investigation a packed-filter bioreactor was employed to produce hydrogen utilizing an expired soft drink as a substrate. The effects of feeding substrate concentrations ranging from 19.51 10.19 5.34 3.48 to 2.51 g total sugar/L were examined and the position of the packed filter installed in the bioreactor at dimensionless heights (h/H) of 1/4 2/4 3/4 and 4/4 was studied. The results revealed that with a substrate concentration of 20 g total sugar/L and a hydraulic retention time (HRT) of 1 h a packed filter placed at the half-height position of the bioreactor (h/H 2/4) has the optimal hydrogen production rate hydrogen yield and average biomass concentration in the bioreactor resulting in 55.70 ± 2.42 L/L/d 0.90 ± 0.06 mol H₂/mol hexose and 17.86 ± 1.09 g VSS/L. When feeding substrate concentrations varied from 20 10 to 5 g total sugar/L with the packed-filter position at h/H 2/4 Clostridium sp. Clostridium tyrobutyricum and Bifidobacterium crudilactis were the predominant bacteria community. Finally it was discovered that the packed-filter bioreactor can produce stable hydrogen in high-strength organic effluent.