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Preserving the historical and artistic heritage is a topic of central interest, especially in countries that have particularly old heritage such as Italy. This study concerns the monitoring of environmental conditions of an ancient church in the center of Naples, a beautiful example of Italian Gothics, which, besides the absolute value of the architecture, even preserves works of art of special significance. The measurement campaign, performed during two typical winter weeks, was necessary to calibrate a dynamic energy model of the church. Then, a radiant floor was designed, to provide a space heating service for the Choir, used for conferences and events, so that the improvement of microclimatic conditions, in winter, can contribute to preserving artifacts (e.g., too cold conditions can induce cracks of wooden materials) and improve occupants' thermal comfort, without compromising the historical/artistic value of the church. The monitoring revealed that the indoor microclimatic conditions do not satisfy the ideal ranges for the conservation of the artistic heritage, and that the indoor environment is uncomfortable for the occupants. The positive effects of the new heating systems were also evaluated, by means of simulations performed starting from the calibrated energy model.

To achieve the goal of decarbonization by 2050, the existing buildings, both private and public, should be renovated. Concerning public buildings, the annual renovation rate of 3% envisaged by Directive 2012/27/EU should be increased to meet the objectives set at the European level in terms of energy efficiency. The stringent targets have been confirmed by the “fit for 55” package. In this paper, a university building in Naples (South Italy, typical Mediterranean Climate) is investigated. It is brought to the standard of nearly zero energy building through different energy efficiency measures. Based on the lifespan of the individual retrofit measure, a reasonable payback period is set. Then the incentive needed to get it is evaluated. What emerges is that greater incentives are required, even up to 80%, for interventions that have a longer lifespan, i.e., the thermal insulation of the building envelope. A form of incentive equal to 40% of the investment, on the other hand, would make it possible to pay off all the interventions in about 10 years, insulation of external vertical walls and roof, replacement of transparent building envelope and installed systems, installation of a photovoltaic system. This solution would make the building a nZEB allowing a reduction of the total primary energy consumption of about 41% and a reduction of CO2 emissions of 46%.

In this paper a building-plant system consisting in a housing module with 3D printed walls and a wooden roof is simulated with the dynamic simulation software TRNSYS 18 in coupling with an electric heat pump mainly driven by the electricity of a photovoltaic plant. Energy flows characterizing the system are dynamically assessed and on an annual basis it is evaluated if the condition of nearly Zero Energy Building (nZEB) is reached. Two further indexes - called Building Level of Energy Autonomy (BLEA) and Building Level of Energy Exported (BLEE) - are also calculated to estimate the energy autonomy and the level of energy exported in the proposed configurations. A parametric analysis considering two peak powers for the photovoltaic system (6.12 kWp and 12.24 kWp) and different sizes for the battery (from 2.16 kWh to 25.92 kWh) are investigated. Results highlights that with both photovoltaic (PV) plant layouts a positive yearly energy balance is obtained. The energy dependence decreases progressively till a certain electric storage capacity (15.12 kWh and 17.28 kWh). Over these values the BLEA stabilizes around 94% and 97% with the smallest and largest dimension of the solar field, respectively. In these conditions 44% and 68% of the produced electricity is fed into the distribution grid.

The use of biomass as a feedstock for renewable energy and biomaterials production is gaining increasing attention due to economic and environmental issues. Among all substrates, the organic fraction of municipal solid waste represents a valuable resource for anaerobic digestion facility. This process generates biogas, digestate and leachate. The last two streams are by-products, with potential harmful environmental impact and significant disposal costs. Thus, a proper handling of these biowastes is needed. In the present study, a bench-scale hydrothermal carbonization reactor was operated with two mixtures of digestate and water or leachate varying the residence time and the reaction temperature. The results indicated that aforementioned operating parameters affect the composition and the yield of the obtained hydrochar and that the substitution of water with leachate is technically feasible.

The H2020FET-OPEN project AMADEUS proposes the proof-of-concept of a novel solar thermal energy storage system based on phase change materials, such as pure silicon and boron with a high melting point (>1400 °C) and a high latent heat capacity (10 times higher than the molten salts), combined with a solid-state energy conversion mechanism based on a hybrid thermionic-photovoltaic (TIPV) device. The TIPV cell, operating at very high temperatures (up to 2000 °C) produces and exploits high electronic and photonic fluxes to convert heat directly and efficiently into electric power at very high power rates. Specifically, our main aim is the development of low work-function thermionic electrodes able to manage a large current density at the operating temperatures. The thermionic cathode is under development with the deposition of thin films of nanostructured borides (lanthanum, cerium) obtained by nanosecond and femtosecond pulsed laser deposition and/or electron-beam evaporation on refractory substrates. Single-crystal borides already demonstrated to be efficient thermionic emitters due to a low work function (typically < 3 eV) and a high melting point (>2200 °C). The challenge here is to extend these properties to low-cost large-area nano/micro-structured boride thin layers. On the other hand, the anode of the TIPV converter is a thin layer deposited on a PV cell. The layer, with a work-function even lower than the cathode one to collect the emitted electrons, must also be transparent to the blackbody radiation coming from the hot cathodic component so to allow the PV cell to exploit this photon flux. Ultra-thin layers of alkali metal compounds (barium and caesium) are under development by electron-beam evaporation and magnetron sputtering as anodic coatings. Grazing incidence x-ray diffraction, scanning-electron and atomic-force microscopies, Raman and x-ray spectroscopies were used to investigate the chemical-physical properties of all the deposited thin films, allowing us to optimize their functional properties. Ultraviolet photo-spectroscopy and thermionic emission measurements were performed to evaluate the work-functions and the operating temperature ranges of the emitting/collecting layers.