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Paraguay is also joining the worldwide movement towards economy decarbonization by considering hydrogen as a viable option. Given Paraguay’s abundant renewable energy resources, boasting approximately 8.7 GW of installed hydroelectric capacity, as well as its cost-effective electricity, the country is attracting significant interest from various companies looking to engage in large-scale production of green hydrogen. However, Paraguay is currently experiencing a significant increase in electricity demand, with a growth rate of approximately 8% per year. By 2033, the country’s power system has the potential to attain a generation reserve margin of 12% if this pattern persists. An additional crucial aspect to consider is that the operator of the national electricity grid (ANDE) is currently developing various scenarios to accommodate the increasing demand for electricity energy. Nevertheless, these scenarios fail to consider the potential impact of widespread hydrogen production on the power grid. This paper aims to close the existing gap by introducing multiple scenarios for electricity demand that incorporate hydrogen production facilities linked to the National Interconnected System.

This paper describes a multi-criteria tool for the performance comparison of alternative and conventional on board energy systems for maritime sector, both for hotel and propulsion loads, depending on the mission taken into account. The tool, named HELM (Helper for Energy Layouts in Maritime applications), carries out this analysis based on an extended and up-to-date market database of many technologies in terms of power units and suitable fuel storage systems. A wide range of maps has been created, correlating costs, volumes, weights, emissions and fuel environmental hazards with the installed power and the operational hours, given by the user as input. In this work, different maritime vessels typologies are investigated and the choice of the best solution is performed for each one, considering the single evaluation parameters. It is worth noting that the multi-criteria analysis carried out has a general approach, allowing it to give preliminary information on the energy system, in order to respect new requirements (e.g. more and more stringent normative in terms of pollutant emissions in ports and restricted areas). HELM can be used for many design approaches, either for a new ship project or for already existing ships retrofit; furthermore, the database can be easily extended to other generation and storage technologies.

This paper aims to present a feasibility study for clean production, storage and distribution of large amounts of hydrogen, starting from low-cost available renewable electrical energy. Paraguay and Brazil own equally the binational company ITAIPU Hydroelectric Plant (14 GW, about 96,000 GWh/year of production). 50% of this energy corresponds to Paraguay: however, since its energy demand is quite low, a large amount of this energy is sold to Brazil, receiving a compensation of 10 $/MWh. In this context, seeking for ways of adding value to generated electricity, this paper assesses the potential of clean H2 production by water electrolysis, simulating the use of one generator unit of the mentioned company (700 MW) and discussing two alternatives for the produced hydrogen: a) using it for ammonia production as base for fertilizers; b) using it for passenger cars. A detailed thermo-economic analysis is performed using a dedicated software developed by the authors. The results show that production is economically feasible for both cases, moreover the process is completely clean and significant amounts of oxygen are produced, potentially representing an additional revenue for the process.

This paper aims to develop a tool for the performances comparison of innovative energy systems on board ships, both for concentrated and distributed generation applications. In the first part of the study, the tool database has been developed throughout a wide analysis of the available market solutions in terms of energy generation devices (i.e. fuel cells, internal combustion engines, micro gas turbines), fuels (hydrogen, natural gas, diesel) and related storage technologies. Many of these data have been collected also thanks to the laboratory experience of the authors’ research group on different innovative energy systems. From the database, a wide range of maps has been created, correlating costs, volumes, weights and emissions with the installed power and the operational hours required, given by the user as input. The tool highlights the best solution according to the different relevance chosen by the user for each key parameter (i.e. costs, volumes, emissions). In the second part, two different case studies are presented in order to underline how the installed power, the different ship typology and the user requirements affect the choice of the best solution. It is worth noting that the methodology has a general value, as the tool can be applied to both the design of new ships, and to the retrofit of already existing ships in order to respect new requirements (e.g. more and more stringent normative in terms of pollutant emissions in ports and restricted areas). Furthermore, the database can be easily extended to other generation and storage technologies.

As International Maritime Organization set 2030 and 2050 targets to reduce CO2 emissions in maritime sector, the investigation of innovative clean solution as hydrogen fuel cells for clean energy generation onboard is gaining more and more value. The present study investigates the thermal integration between PEM fuel cells and metal hydrides (for hydrogen storage) on board the first Italian zero-emissions ship with hydrogen and batteries propulsion, named ZEUS, built by Fincantieri Yard and launched in 2022. A model-based approach is developed to ensure the system's control at different load demands for the vessel, including transient conditions. The study focuses on the most critical conditions for fuel cells during navigation, namely from maximum to minimum power and vice-versa. Load reduction does not imply particular issues, while load maximum increase may cause some problems in terms of stability, negatively affect fuel cell stacks lifetime. Three solutions are investigated and compared to solve the problem to achieve a safe and robust control system: (i) decrease the current ramp for fuel cells from 50 to 10 A/s; (ii) introduce an intermediate load step; (iii) adopt an advanced Model Predictive Control strategy. • Integration of PEMFC and metal hydrides (MH) for zero-emissions ship is presented. • A Matlab-Simulink model is developed for the PEMFC and MH systems. • Two control systems (PID, MPC) are investigated for strong energy load variations. • Three possible solutions are presented to avoid problems to PEMFC in transients. • The MPC results the best solution to avoid thermal stress on PEMFC. [ABSTRACT FROM AUTHOR]

The International Maritime Organization (IMO) has concerned significant care to the reduction of ship emissions and improvement of energy efficiency through operational measures. One of those measures is ship speed reduction, which is classified as a short-term measure; in which the speed is reduced below its designed value. The present paper aims at evaluating the potential energy efficiency, and environmental and economic benefits because of applying speed reduction measures. The research methodology depends on establishing a simple mathematical model for technical, environmental, and economical aspects because of this concept. As a case study, container ships from different categories in a range of 2500-15,000 twenty-foot equivalent units (TEU) are investigated. The results show that a 2500 TEU ship can comply with the energy efficiency existing ship index (EEXI) by reducing the service speed to 19 knots. While for the bigger ships, the service speed must be 21.5 knots or below. Furthermore, the operational carbon intensity indicator (CII) has been evaluated for the case studies and found that the CII rating will keep its score between A and C levels if the service speed is equal to or below 19.5 knots. Moreover, the annual profit margin of the ship will be calculated based on applying speed reduction measures. Based on the economical results, the annual profit margin value, and its corresponding optimum speed change with the size of the vessel and the applicable status of carbon taxes., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)