Papers by Gabriele Comodi
Sciyo eBooks, Sep 27, 2010
Therefore a regenerator is usually installed between the compressor and the combustion chamber. F... more Therefore a regenerator is usually installed between the compressor and the combustion chamber. Figures 1 and 2 show, respectively, the layout and corresponding thermodynamic cycle of a typical cogeneration MGT.
Applied Energy, 2010
Modelling and prediction of wind speed are essential prerequisites in the sitting and sizing of w... more Modelling and prediction of wind speed are essential prerequisites in the sitting and sizing of wind power applications. The profile of wind speed in Nigeria is modelled using artificial neural network (ANN). The ANN model consists of 3-layered, feed-forward, back-propagation network with different configurations, designed using the Neural Toolbox for MATLAB. The monthly mean daily wind speed data monitored at 10Â m above ground level for a period of 20Â years (1983-2003) for 28 ground stations operated by the Nigeria Meteorological Services (NIMET) were used as training (18 stations) and testing (10 stations) dataset. The geographical parameters (latitude, longitude and altitude) and the month of the year were used as input data, while the monthly mean wind speed was used as the output of the network. The optimum network architecture with minimum Mean Absolute Percentage Error (MAPE) of 8.9% and correlation coefficient (r) between the predicted and the measured wind speed values of...
Social Science Research Network, 2021
Energy Conversion and Management, Feb 1, 2023
Renewable & Sustainable Energy Reviews, Mar 1, 2021
Liquid air energy storage (LAES) represents one of the main alternatives to large-scale electrica... more Liquid air energy storage (LAES) represents one of the main alternatives to large-scale electrical energy storage solutions from medium to long-term period such as compressed air and pumped hydro energy storage. Indeed, characterized by one of the highest volumetric energy density (≈200 kWh/m 3), LAES can overcome the geographical constraints from which the actual mature large-scale electrical energy storage technologies suffer from. LAES is based on the concept that air can be liquefied, stored, and used at a later time to produce electricity. Although the liquefaction of air has been studied for over a century, the first concept of using cryogenics as energy storage was proposed for the first time in 1977 and rediscovered only in recent times. Indeed, the need for alternative energy vectors in the energy system attracted many researchers to discover the potential of the use of cryogenic media. This has brought the realization of a first LAES pilot plant and a growing number of studies regarding LAES systems. The main drawback of this technology is the low round-trip efficiency that can be estimated around 50-60% for large-scale systems. However, due to its thermo-mechanical nature, LAES is a versatile energy storage concept that can be easily integrated with other thermal energy systems or energy sources in a wide range of applications. Most of the literature published is based on thermodynamic and economic analysis focusing on different LAES configurations. This paper provides a collection of the papers published on LAES and it classifies the various studies conducted in different categories. Future perspectives show that hybrid LAES solutions with efficient design of the waste energy recovery sections are the most promising configuration to enhance the techno-economic performance of the stand-alone system.
To mitigate climate change, a stronger reliance on renewable energy sources is foreseen, and Powe... more To mitigate climate change, a stronger reliance on renewable energy sources is foreseen, and Power-to-Hydrogen systems can be adopted to minimize curtailment losses derived from the intermittent nature of wind and solar power. Among different alternatives, alkaline water electrolysis is the most mature process for hydrogen production using sustainable electricity as its main energy source. The mathematical modelling of the alkaline electrolysis process is a crucial tool to improve green hydrogen production, energy conversion efficiency, sizing (model-based design) and thermal energy management. Although several studies have investigated alkaline electrolysis modelling, these analyses often neglect property variations along the stack area and its economic implications. In this work, the need for increasing the modelling complexity in system models by introducing a one-dimensional model of the alkaline electrolyzer cell/stack is investigated. With this, several operation parameter variations can be modelled, and among these, the internal temperature variation plays a crucial role in both technical and economic aspects. Results show that efficiency could vary between 58-70% while the Levelized cost of hydrogen is within the range of 1.3-1.6 €/kg, when various inlet-outlet temperature differences are considered. Furthermore, from both technical and economic aspects, the optimal temperature control of alkaline electrolysis is to maintain a very low-temperature difference (~1°C), from inlet to outlet, controllable with the alteration of the electrolyte flow rate.
Energies, Oct 18, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
In the contest of household energy management, a growing interest is addressed to smart system de... more In the contest of household energy management, a growing interest is addressed to smart system development, able to monitor and manage resources in order to minimize wasting. One of the key factors in curbing energy consumption in the household sector is the amendment of occupant erroneous behaviours and systems malfunctioning, due to the lack of awareness of the final user. Indeed the benefits achievable with energy efficiency could be either amplified or neutralized by, respectively, good or bad practices carried out by the final users. Authors propose a diagnostic system for home energy management application able to detect faults and occupant behaviours. In particular a nonlinear monitoring method, based on Kernel Canonical Variate Analysis, is developed. To remove the assumption of normality, Upper Control Limits are derived from the estimated Probability Density Function through Kernel Density Estimation. The proposed method is applied to smart home temperature sensors to detect anomalies respect to efficient user behaviours and sensors and actuators faults. The method is tested on experimental data acquired in a real apartment.
Frontiers in Energy Research, Apr 21, 2021
Technologies capable of efficiently exploiting unavoidable CO 2 streams, have to be deeply invest... more Technologies capable of efficiently exploiting unavoidable CO 2 streams, have to be deeply investigated and deployed during the transition phase to achieve long-term climate neutrality targets. Among the technologies, Molten Carbonate Cells (MCC) Operating in Electrolysis Mode (MCEC) represents a promising facility to valorize CO 2rich waste streams, which are typically available in industrial plants, by their conversion into a high-value H 2 /CO syngas. These gaseous products can be reintegrated in a plant or reused in different applications. This study analyzes the integration of a system of the MCEC unit under different operating conditions in terms of composition, current density, and the utilization of fuels in a steam-reforming process of an Italian oil refinery via a mixed experimental-simulative approach. The aim of the current study is to assess the improvement in the overall product yield and further impacts of the MCEC unit on the plant efficiency. The results have shown that it is possible to obtain an electrochemical Specific Energy Consumption for the production of H 2 of 3.24 kWh/Nm 3 H2 using the MCEC, whereby the possible integration of a 1-MW e module with a reformer of the proposed plant not only increases the hydrogen yield but also decreases the amount of fuel needed to assist the reforming reaction and separates a CO 2 stream after additional purification via an oxy-fuel combustor, consequently determining lower greenhouse gases emissions.
Springer proceedings in energy, 2020
The identification of techniques aimed at a rational use of electric power has nowadays become mo... more The identification of techniques aimed at a rational use of electric power has nowadays become more important than the production of energy itself. One of the causes for this is the progressive saturation of the Italian electricity grid, which is increasingly subject to connection requests, mainly due to the development of plants which make use of renewable energy sources.
Energy Reports
Optimized controls are particularly promising for flexible and efficient management of space heat... more Optimized controls are particularly promising for flexible and efficient management of space heating and cooling systems in buildings. However, when controls are based on predictive models, their effectiveness is affected by the reliability of the models used. In this paper we propose a quantification analysis of some of the main uncertainty factors that can be observed in an optimal control really implemented in a building. A day-ahead optimal scheduling was applied to the heating system (composed of smart electric heaters with thermal storage) of a single room in an office building located in Osimo (Italy). The control algorithm is formulated to determine the charging periods of the heaters with the objective of minimizing the withdrawal of energy from the grid. The control takes into account the electricity produced by a photovoltaic plant and must maintain the internal air temperature close to an imposed setpoint. Firstly, the actual application of the control is shown during two selected days. Secondly, the analysis is extended to quantify the impact on the control performance of the prediction uncertainty of the input variables. The variable that has the greatest impact is the weather forecast and, specifically, the cloudiness index, which determines the solar gains. The different moment in time in which the weather forecast is predicted has proved to have a significant impact on the charging periods of the heaters (expected variation ranges from-50% to + 100%) and on the prediction of the indoor air temperature (variations observed up to 40%).
Sustainable Energy Technologies and Assessments
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Papers by Gabriele Comodi