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This paper regards the design and dynamic modelling of a greenhouse coupled with renewable energy technologies to obtain a hybrid renewable energy plant as an optimal solution in the green farm framework. The considered technologies are PV panels, solar thermal collectors, and a biomass auxiliary heater. The system is also coupled with a pyrogasifier, supplied by wood and agricultural waste in the framework of a biocircular economic approach. To supply the investigated user, with a "green farm" located in Castelvolturno (Naples, South of Italy) reducing the energy consumption and operating costs, all of the main components of the plant were suitably designed. The operation of the designed components was simulated by a dynamic simulation model developed by TRNSYS software and validated by means of the literature results. A comprehensive energy, economic, and environmental analysis of the greenhouse is presented. The main results suggest that the investigated renewable plant reduces the total equivalent CO2 emissions by 148.66 t/y. Considering the current high increases in energy prices as a result of the energy crisis due to the war, the system shows very significant profitability with a simple payback of only 1.7 years. [ABSTRACT FROM AUTHOR]

Dynamic simulation is a powerful tool for accurately evaluating the thermal demands of buildings and assessing the impact of energy refurbishment actions on their final consumption. Conversely, semi-stationary models are widely adopted in commercial applications for its simplified approach, which reduce calculation times, resulting in standardized results showing a certain deviation with respect to the real energy This paper presents the energy and economic comparison between the dynamic simulation and semi-stationary approaches for the calculation of primary energy demand of residential buildings. The semi-stationary method, used by the legislation to calculate the buildings energy label, is based on an energy performance parameter, not representative of the real energy demand. Conversely, an approach based on dynamic simulation provides a more reliable estimation of the primary energy demand. The main novelty of this paper is to numerically prove that the energy and economic savings calculated by means of software based on the current legislation may be overestimated. In this work, the dynamic simulation of the building-plant system is performed by TRaNsient SYstem Simulation (TRNSYS) program. Each building apartment is divided in thermal zones, where the internal heat gains are defined in detail. The semi-stationary simulation of the building-plant system is performed according to the Italian standard UNI TS 11300. The models allow one to evaluate the yearly primary energy demand, along with the energy bill and CO 2 emissions. A specific case study is developed for a residential building located in Naples (Italy). The models are used to calculate the building energy demand for several scenarios, considering different thermal transmittances of the building elements. The results show that the semi-stationary method overestimates of primary energy saving, equal to 64.7 %, with respect to the one calculated with the dynamic approach, equal to 43.2 %. • Semi-stationary and dynamic simulations were compared for residential buildings. • Critical evaluation of energy and economic savings due to the building refurbishment. • Primary energy savings of 65 % and 43 % by semi-stationary and dynamic simulation. • Dynamic simulation is needed within the legal frame of energy efficient buildings. [ABSTRACT FROM AUTHOR]

The paper presents an in-depth analysis of a novel scheme for the sustainable mobility, based on electric vehicles, photovoltaic energy and electric energy storage systems. The work aims to analyse such innovative system, putting in evidence its advantages in comparison to a conventional one, based on the grid-to-vehicle technology. The study also provides interesting guidelines for potential users and system designers. Two case studies are presented: i) the taxi fleet of the city centre of Naples and ii) the cargo vans of the city of Salerno; both towns are in Southern Italy. For each case, the hourly power consumption of the vehicles was evaluated, as a function of the daily trip length. An accurate procedure was implemented to select the sites suitable for the installation of the charging stations, including a photovoltaic field and an electric storage system. A comparison was also performed between two different electric storage technologies: lead-acid and lithium-ion battery. The case studies were analysed by means of a detailed dynamic simulation model, developed in TRNSYS. A sensitivity analysis was also performed, to evaluate how different values of the most important design and operating parameters affect the system overall performance. It was found that the results are mostly affected by solar field area, capacity of the energy storage system and investment cost. The comparison between the two selected storage technologies did not exhibit significant differences. For both the cases investigated, it was found that, during the summer, solar energy covers an important amount of the total energy demand. On the contrary, in winter the amount of energy provided by the public electric grid was high. From an economic point of view, assuming a lithium-ion battery capital cost equal to 90 €/kWh, acceptable pay-back periods (about 6 years) were obtained, for both the applications considered. • Dynamic analysis of electric vehicle solar parking focused on sustainable mobility concept. • Transport/statistical model development for both private/public transport sector. • Environmental, energy and economic comparison between lead-acid and lithium-ion battery. • Interesting pay-back periods in case of lithium-ion battery capital cost expected reduction. [ABSTRACT FROM AUTHOR]

• Development of a novel approach for studying and addressing the issue of heat theft. • Definition of a novel vote parameter assessing for which penalty the heat theft is profitable. • A penalty up 2.5 times the constant fee would limit unwanted behavior of heat theft. • The constant fee should account for 40–60% of the total energy bill. European Union is facing a dramatic energy crisis, due to the huge increase of the natural gas cost, due to the Russian-Ukrainian war. In this framework, the fair allocation of natural gas costs, used for space heating purposes in residential centralized heating systems, is becoming a crucial issue. These systems suffer for the heat theft phenomenon, where an unheated apartment may benefit of the heat transfer from the surrounding heated apartments. Unfortunately, there is no consensus regarding a suitable heat accounting method, implemented in order to limit heat thefts. In this work, two novel billing strategies are proposed. In the first one, the heating cost includes both a variable fee and a constant fee. The second one also considers a penalty for the unheated apartments. A case study is analyzed. It consists of a multifamily building including 4 floors and located in Naples. This building is equipped with a centralized heating system, coupled with radiators, variable speed pumps, thermostatic valves, and heat metering devices. A suitable dynamic simulation model is developed in TRNSYS 18 environment to analyze the energy and economic performance of the system. The comfort parameters of unheated users are also analyzed and discussed. The proposed billing strategies are able to smooth the heating bill increase for the heated apartments adjacent to the unheated user. The novel billing strategy proposed by this research can significantly mitigate the heat theft issue. In particular, results show that the penalty should be almost 2.5 times the constant fee for preventing the unheated user issue. Simulations also show that installing a suitable thermal insulation for the walls among adjacent apartments may dramatically limit the heat thefts. However, insulating such walls may result often unfeasible for the owners of the apartments, due to reduction of the floor area and to the major refurbishment required. [ABSTRACT FROM AUTHOR]

Smart energy networks, based on the integration of thermal and electric technologies, are becoming more attractive to match the increasing energy demand with minimum environmental impact. The design and optimization of a smart energy network based on a combined heat and power system, a photovoltaic solar field, an electric energy storage system and electric vehicles is presented in this work. The investigated system is designed to match the power, heating and cooling demands of a district of 50 residential buildings. The cogeneration system, operating in thermal tracking mode, is based on a reciprocating internal combustion engine, fuelled by natural gas. The engine waste heat is used to match the heating and domestic hot water demands of the residential district. The power produced by both engine and photovoltaic panels is used to match the power demand of the district, including the electric vehicles. The electric energy storage system based on lithium-ion technology is included to shave the peaks of power demand and to decouple demand from supply. The whole system, including all final users, was dynamically simulated in TRNSYS 18. The model was used to develop a case study regarding a district of 50 residential buildings located in Naples (South of Italy). A thermoeconomic optimization of the layout was also performed, using Genopt software. The results of the case study showed that the proposed system exhibits promising performance, reducing CO 2 emissions by 62%, with a payback period of 6.39 years. In the optimal scenario, the peak power of the photovoltaic field was found equal to 3.50 MW, with a capacity of the electric energy storage system of 6.70 MWh. The corresponding payback period was equal to 6.31 years. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dynamic evaluation of economic and energy benefits due to thermostatic valve installation. • Dynamic evaluation of economic and energy benefits due to heat metering installation. • The adoption of both thermostatic valves and heat metering least to a payback period lower than 2 years. • Analysis carried out considering several shapes of typical building. The aim of this paper is to propose a novel approach in order to accurately calculate the energy and economic savings due to the use of heat metering and thermostatic valves in residential buildings. The paper aims at proving that the present simplified approaches used in European Legislation may lead to significantly underestimate the profitability of this technology. The study is developed for four different typologies of buildings located in the city of Naples (South of Italy), including their geometrical and thermophysical properties. The buildings are first modelled in Google Sketchup and subsequently linked to the TRNSYS environment, which also includes a detailed model of the piping systems. The models allow one to evaluate, for every period of the year, energy demand, energy supplied by radiators, heat gains, transmission, etc. The developed models are used to calculate energy demands for three scenarios for each type of building: centralized heating systems not equipped with heat metering; thermostatic valves without heat metering; heat metering and thermostatic valves. The possible savings related to thermostatic valves and heat metering are estimated using the developed model. The results are compared with the ones provided by the Italian Standards. Results show that the thermostatic valves adoption leads to a significant reduction, up to 50%, of the thermal energy demand of the residential buildings and that all the proposed systems exhibit a remarkable economic profitability, with a payback period lower than 1.7 years. [ABSTRACT FROM AUTHOR]

This paper proposes a novel approach in order to accurately calculate the savings due to heat metering. The approach is based on a detailed dynamic simulation of building-plant systems. The building is geometrically modelled in Google Sketchup and linked to the TRNSYS environment, including an extremely detailed model for the simulation of building thermo-physical behavior. All the models are validated using the data provided by the occupants. The model allows one to evaluate the yearly energy demand, energy supplied by radiators, heat gains, etc. A specific case study is developed for a residential building located in Naples (South Italy). The developed model is used to calculate the building energy demand for 3 scenarios: centralized heating system not equipped with heat metering; centralized heating system with thermostatic valves and not equipped with heat metering; centralized heating system with thermostatic valves and equipped with heat metering. Results show that in case of centralized heating systems equipped with thermostatic valves and heat metering devices, thermal energy savings up to 64% can be reached mainly when the system operates for many hours per day, leading to discounted pay back periods lower than 4 years. • Dynamic analysis of energy performance of building adopting thermostatic valves. • Dynamical analysis of heat metering devices for a residential building. • Dynamic analysis of building energy performance. • Thermostatic valves and heat metering devices are able to reduce by 64% building thermal energy demand. [ABSTRACT FROM AUTHOR]

In this research, a technoeconomic comparison of energy efficiency options for energy districts located in different climatic areas (Naples, Italy and Fayoum, Egypt) is presented. A dynamic simulation model based on TRNSYS is developed to evaluate the different energy efficiency options, which includes different buildings of conceived districts. The TRNSYS model is integrated with the plug-in Google SketchUp TRNSYS3d to estimate the thermal load of the buildings and the temporal variation. The model considers the unsteady state energy balance and includes all the features of the building's envelope. For the considered climatic zones and for the different energy efficiency measures, primary energy savings, pay back periods and reduced CO2 emissions are evaluated. The proposed energy efficiency options include a district heating system for hot water supply, air-to-air conventional heat pumps for both cooling and space heating of the buildings and the integration of photovoltaic and solar thermal systems. The energy actions are compared to baseline scenarios, where the hot water and space heating demand is satisfied by conventional natural gas boilers, the cooling demand is met by conventional air-to-air vapor compression heat pumps and the electric energy demand is satisfied by the power grid. The simulation results provide valuable guidance for selecting the optimal designs and system configurations, as well as suggest guidelines to policymakers to define decarbonization targets in different scenarios. The scenario of Fayoum offers a savings of 67% in primary energy, but the associated payback period extends to 23 years due to the lower cost of energy in comparison to Naples. [ABSTRACT FROM AUTHOR]

• Dynamic tool for the evaluation of the energy demand of a residential district. • Comparison of several measures reducing residential district energy consumption. • Performance evaluation of several heat pump technologies coupled with photovoltaic. • The proposed layouts achieve promising energy environmental and economic performances. • The use of air-to-air heat pumps for space heating is extremely profitable. In European Union Countries, local authorities have developed their own Sustainable Energy Action Plan aiming at planning the urban strategies to achieve the European Union and national 2020 energy targets. This document is used for detecting and deploying the energy measures which each municipality should adopt in order to reduce the environmental impact of the municipality activities. Further efforts are expected to define the strategies for achieving 2050 goals. In this framework, this work deals with the dynamic estimation energy saving actions for small districts located in different Italian weather zones (Naples and Turin, located in South and North Italy, respectively). The data of the Sustainable Energy Action Plan were used to develop suitable dynamic models, implemented in TRNSYS environment, including different buildings of selected districts. In particular, all the buildings were modelled by means of the Type 56 of TRNSYS, coupled to the Google SketchUp TRNSYS3d plug-in. By means of Type 56, it is possible to take into account and simulate the buildings geometry, envelope, windows, lighting, machineries heat gains schedule as well as the buildings users' occupation and activity. Given the loads, several energy efficient renovation alternatives based on the adoption of air-to-air conventional and carbon dioxide heat pumps, evacuated thermal collectors and photovoltaic panels, as well as the envelope renovation of all the public and private buildings of the district, are proposed and compared. Results, obtained by detailed dynamic energy and environmental analyses, can be used as guidelines for the local authorities to implement suitable energy efficiency actions of existing buildings in order to reduce both the thermal energy and carbon dioxide emissions due to the building space heating/cooling, domestic hot water and electricity. The proposed renewable layout for Naples case study achieves a primary energy savings of 58% with a payback period of 4 years. The renewable layout for Turin case study achieves a primary energy savings of 76% with a payback period of 10.6 years. [ABSTRACT FROM AUTHOR]

Highlights • Dynamic simulation model of a novel vehicle to net zero energy building layout. • System environmental and thermo economic analysis coupled with electric vehicle. • Investigation of the electric vehicle charging effects on the system performance. • The system is economically feasible only with a small capacity storage system. • Electric vehicle allows one a significant equivalent CO 2 emissions reduction. Abstract This paper analyses the energy, environmental and economic performance of a future scenario where electric vehicles are connected to efficient buildings powered by building integrated flat-plate photovoltaic/thermal collectors, equipped with electric energy storage. The produced renewable electricity and thermal energy are exploited for building electrical and thermal applications. The surplus of produced electricity is stored into the electrical battery and used to charge the electric vehicle. The proposed system is modelled and dynamically simulated within the TRNSYS environment, where special attention is paid to the design of suitable system control strategies, aiming at optimizing the exploitation of the solar energy for electricity and heating purposes. To this aim, a sensitivity analysis is also carried out to find out the optimal system configuration. A case study analysis, relative to the weather zone of Naples (South Italy), is conducted to evaluate the energy, economic and environmental feasibility of the investigated scenario. Simulation results show that, with respect to a reference system, a remarkable reduction of electricity from the grid is achieved, corresponding to a primary energy saving equal to 57.66%. A reduction of 51.63% of CO 2 emissions and a simple pay payback period equal to 11.64 years are achieved. [ABSTRACT FROM AUTHOR]