Design and experimental set-up of hydrogen based microgrid: characterization of components and control system development

In this study, the implementation of a hydrogen microgrid is investigated, considering the integration of H2 production, storage, and energy conversion to feed a typical end-user. A remote control system has been realized through LabVIEW software, allowing to monitor real-time all the devices and analyze their performances. The integrated system is composed of a PEM electrolyzer (325 W), a storage system based on metal hydrides (two tanks, 54 g of hydrogen each, 1.08 wt%) and an energy converter (PEM Fuel Cell stack, 200 W). A programmable electronic load was used to set a power demand throughout the year, simulating an end-user. Data collected from each component of the micro-grid were used to characterize the energetic performance of the devices, focusing on the H2 production via electrolyzer, charging cycles of the H2 storage system, and energy conversion efficiency of the FC stack. Finally, the global efficiency of the microgrid is computed. Even though the system is realized in laboratory scale, this circumstance will not invalidate the significance of the configuration due to modularity of all the technologies that can be easily scaled up to realistic scales

Enabling Railway AM Optimization Using a Rationale KPIs Framework

Often the top management, in the phase of asset controls, finds itself overwhelmed by the availability of a huge amount of Key Performance Indicators (KPIs). Most managers are struggling to understand and identify the vital few management metrics and instead collect and report a vast amount of everything that is easy to measure. As a consequence they end up drowning in data while thirsting for information. This condition does not allow a good management of the systems. The research aim’s is to help the Asset Management System (AMS) of a railway infrastructure manager using Business Intelligence (BI) to have a KPIs management system in line with the principles of AM presented by the normative ISO 55000 - 55001 - 55002 and UIC (International Union of Railways) guideline, for the specific case of a railway infrastructure. This work starts from the study of these regulations, continues with the exploration, definition and use of KPIs. Subsequently KPIs of a generic infrastructure are identified and analyzed , especially for the specific case of a railway infrastructure manager. These KPIs are fitted in the internal elements of the AM frameworks (ISO-UIC) for systematization. Moreover an analysis of the KPIs now used in the company is made, compared with the KPIs that an infrastructure manager should have. Starting from here a Gap Analysis is made for the optimization of AMS

Syngas quality in fluidized bed gasification of biomass: comparison between olivine and K-feldspar as bed materials

The relevance of selecting an appropriate bed material in fluidized bed gasification is a crucial aspect that is often underestimated. The ideal material should be economical, resistant to high temperatures and have small chemical interaction with biomass. However, often only the first of such three aspects is considered, neglecting the biomass–bed interaction effects that develop at high temperatures. In this work, olivine and K-feldspar were upscale-tested in a prototype fluidized bed gasifier (FBG) using arboreal biomass (almond shells). The produced syngas in the two different tests was characterized and compared in terms of composition (H2, CH4, CO, CO2, O2) and fate of contaminants such as volatile organic compounds (VOCs), tar and metals.. Moreover, the composition of olivine and K-feldspar before and after the biomass gasification process has been characterized. The aim of this work is to show which advantages and disadvantages there are in choosing the most suitable material and to optimize the biomass gasification process by reducing the undesirable effects, such as heavy metal production, bed agglomeration and tar production, which are harmful when syngas is used in internal combustion engines (ICE). It has been observed that metals, such as Ni, Cu, Zn, Cd, Sn, Ba and Pb, have higher concentrations in the syngas produced by using olivine as bed material rather than K-feldspar. In particular, heavy metals, such as Pb, Cu, Cd, Ni and Zn, show concentrations of 61.06 mg/Nm3, 15.29 mg/Nm3, 17.97 mg/Nm3, 37.29 mg/Nm3 and 116.39 mg/Nm3, respectively, compared to 23.26 mg/Nm3, 11.82 mg/Nm3, 2.76 mg/Nm3, 24.46 mg/Nm3 and 53.07 mg/Nm3 detected with K-feldspar. Moreover, a more hydrogen-rich syngas when using K-feldspar was produced (46% compared to 39% with olivine)

Assessment of Hydrogen and LNG buses adoption as sustainable alternatives to diesel fuel buses in public transportation: Applications to Italian perspective

This work deals with a technical and economical comparison between hydrogen and liquid natural gas (LNG) fueled buses with reference to the standard solution based on diesel fuel internal combustion engines. The level of service is evaluated considering the number of buses replaced and the average kilometers traveled each year for two levels. The economical comparison is made using the Total Cost of Ownership (TCO) method considering capital and operating costs. The costs of LNG and Diesel (at the pump in Italian market) are estimated with reference to the year 2020. Furthermore, an assessment of greenhouse gas emissions will be carried out starting from energy needs, adopting a “cradle to grave” approach, thus evaluating emissions from the well to the tank and from the tank to the wheel. The results show that the operating costs (0.778 €/km) of LNG solution are lower than the Diesel ones (1.072 €/km), while the hydrogen buses can become competitive in the next few .The production of hydrogen with water electrolysis considering the current electricity costs of the Italian market is expensive and involves a cost to the hydrogen pump 7,60 €/kg which makes the operating cost of the hydrogen solution is equal to about 1.420 €/km which makes this solution uncompetitive. It is also important to underline that the cost of green hydrogen production from water electrolysis strongly depends on the cost of electricity. The Life Cicle Analisis (LCA) analysis shows strong environmental benefits of the hydrogen solution in terms of CO2eq if the hydrogen is produced by electrolysis using renewable energy sources. In the other cases, the advantage of using hydrogen is not very strong as it is associated with the use of fossil fuels that release climate-altering substances

Integration of Floating Photovoltaic Panels with an Italian Hydroelectric Power Plant

The potential of applying a floating PV (FPV) system in an Italian context (namely, Cecita dam and Mucone hydroelectric power plants) is studied. The additional PV energy production, as well as the effect of non-evaporated water on the productivity of the hydropower plant, is analyzed by varying the basin surface coverage. The simulations highlight that the amount of additional hydroelectricity is quite small if compared to the non-FPV system, reaching about 3.56% for 25% basin surface coverage. However, the annual PV energy production is noticeable even at low coverage values. The expected gain in electricity production in the case of 25% basin surface coverage with the FPV plant rises to 391% of that of the actual hydropower plant. This gain becomes even larger if a vertical axis tracking system is installed and the increase is about 436%. The economic analysis confirms that the production costs (USD/kWh) of FPV systems are comparable to those of land-based PV (LBPV) plants, becoming smaller in the case that a tracking system is installed. In particular, the best solution is the one with 15% coverage of the lake. In this case, the levelized cost of electricity for the LBPVs is 0.030 USD/kWh and for the FVPs, with and without tracking, it is equal to 0.032 and 0.029 USD/kWh, respectively