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This paper aims at optimizing the energy performance of an innovative integrated collector-storage solar water heater (ICSSWH) prototype. The system incorporates a high-vacuum gap, which significantly reduces convective thermal losses, and a serpentine absorber system coated with a low-E layer to minimize radiative thermal losses. The methodology is based on a detailed dynamic simulation model, implemented in the MatLab environment, suitable conceived to accurately predict the energy performance and economic profitability of the ICSSWH under various weather conditions and energy market prices. This approach aims to initially identify the most influential geometrical, thermophysical and optical parameters that impact the energy performance of the system through the assessment of different objective functions. After identifying the most influential parameters, the range of existence with the interval step for each variable is defined, and the optimization procedure is conducted to determine the optimal set of variables that maximize / minimize the selected objective functions. To demonstrate the effectiveness of the proposed methodology, a proof of concept was conducted to optimize the energy performance of novel ICSSWH by considering nineteen parameters with the aim of maximizing/minimizing three different objective functions. The results of this analysis yielded various sets of optimized parameters for the ICSSWH.

In this paper a novel Concentrating Photovoltaic/Thermal Glazing system (CoPVTG), developed at the Centre for Sustainable Technologies of the University of Ulster (Belfast, UK), and exploiting concentration technology, is presented and investigated. The innovative device consists in two glazed panels of which the external one is moulded to form several lenses that concentrate the solar radiation onto photovoltaic cells lines. Thanks to the specific behaviour of these lenses, the solar radiation is capable to reach the indoor environment during the winter months (when it's more useful), while it ends onto the photovoltaic cells during the summer months (reducing the solar gains while also providing electricity to the building). To increase the electricity production, a forced air flux can be created inside the glazed cavity to reduce the PhotoVoltaic cells temperature, and the obtained hot air can be exploited for diverse purposes. Finally, such device is conceived to be integrated into existing windows framing to boost its adoption in new or refurbishment construction. With the intention of studying the device under a wide range of boundary and working conditions, a dynamic simulation tool was developed in MATLAB environment and validated trough experimentally gathered data. With this tool it is possible to investigate the performance of the novel device integrated into several buildings. Specifically, a case study analysis was performed by considering an office building located in five different localities. From the conducted analyses, interesting results and design criteria are obtained. Specifically, the CoPVTG adoption returns higher electricity yield vs. standard semi-transparent window, ranging between 54 and 84% in case of cold and hot weather zones, respectively. In term of overall economic performance, the adoption co CoPVTG allow for a HVAC system running cost reduction, for the investigated case study, ranging from 20 to almost 100% depending on the considered weather zone.

Today, the use of renewable energies in buildings represents one of the main ways to reach a sustainable world. Whilst present buildings are still often energivorous systems, in the near future they will have to be converted to (or replaced by) zero energy buildings, also capable to export green energy (produced on-site by renewables) towards other buildings and/or users. This review article focuses on a selection of research papers, presented at the 16th International Conference on Building Simulation (BS 2019), regarding renewable energy applications, energy saving and comfort techniques for buildings. BS 2019 conference was organized in collaboration with the International Building Performance Simulation Association (IBPSA) and it was held at the Angelicum Congress Centre (San Tommaso d’Aquino Pontifex University) in Rome, Italy, during September 2-4, 2019. The conference was attended by 912 researchers and experts, with 660 presented research papers. The above-mentioned selection of papers is included in a dedicated Special Issue of the Renewable Energy - An International Journal (RENE), titled “Renewable energies: simulation tools and applications”. Reported studies are mostly dedicated to models, simulations, and optimization procedures of renewable energy devices. Specifically, photovoltaic systems, building integrated photovoltaic collectors, hybrid photovoltaic/thermal systems, solar thermal collectors as well as other energy efficiency tools are analysed through different simulation approaches and suitable optimization procedures. Attention is also paid to specific case studies related to innovative combinations of renewable energy devices and innovative envelope materials in different building typologies and weather zones. In some papers, solar energy is exploited for space heating and cooling purposes, while in other articles renewables or other energy tools are studied to achieve comfort targets, low grid dependencies, smart building/communities, and mainly the zero energy building goal.

Integrated collector storage units are typically affected by convective and radiative heat losses which significantly reduce their energy performance. To enhance solar collection and heat retention, innovative techniques and novel design of such units are being more and more developed. In this framework, this paper focuses on the design and optimization of a prototypal high-vacuum integrated collector storage solar water heater. The proposed unit allows for reaching high temperatures of the stored water and for reducing the temperature drop during non-collection periods. This goal is achieved by suppressing the convective heat losses into the system by keeping the pressure into the related enclosure below 0.01 Pa and by applying a special selective coating to the solar absorber surface to drastically reduce radiative losses as well. In this paper, details about the system design and the conducted experimental tests are reported. In addition, a new mathematical model able to assess the energy performance of the innovative prototype is presented. This tool, based on a detailed 3-D transient finite-difference thermal network, was validated against the gathered experimental data. By such a tool the optical properties of the adopted selective coating are optimized for maximizing the system thermal efficiency. Finally, with the twofold aim of showing the potentiality of the developed code, as well as the effectiveness of the presented innovative solar collector prototype, a comprehensive case study referred to three different European weather zone is presented. Promising results in terms of energy savings (0.73 MWh/y) and CO2 emission reduction (149 kgCO2/y) are achieved.

In the last years, the Covid-19 outbreak raised great awareness about ventilation system performance in confined spaces. Specifically, the heating, ventilation, and air conditioning system design and operating parameters, such as air change per hour, air recirculation ratio, filtration device performance, and vents location, play a crucial role in reducing the spread of viruses, moulds, bacteria, and general pollutants. Concerning the transport sector, due to the impracticability of social distancing, and the relatively loose requirements of ventilation standards, the SARS-COV-19 outbreak brought a reduction of payload (up to 50%) for different carriers. Specifically, this has been particularly severe for the railway sector, where train coaches are typically characterized by relatively elevated occupancy and high recirculation ratios. In this framework, to improve the Indoor Air Quality and reduce the Covid-19 contagion risk in railway carriages, the present paper investigates the energy, economic and environmental feasibility of diverse ventilation strategies. To do so, a novel dynamic simulation tool for the complete dynamic performance investigation of trains was developed in an OpenStudio environment. To assess the Covid-19 contagion risk connected to the investigated scenarios, the Wells-Riley model has been adopted. To prove the proposed approach's capabilities and show the Covid-19 infection risk reduction potentially achievable by varying the adopted ventilation strategies, a suitable case study related to an existing medium-distance train operating in South/Central Italy is presented. The conducted numerical simulations return interesting results providing also useful design criteria.

In the last decades, the use of centralized energy production is being replaced by distributed energy networks and partially self-sustaining and energy-independent communities. Such approach requires careful design processes, innovative system layouts and smart control strategies, to be properly conducted by means of dynamic simulation. In this framework, this paper presents the design of a highly energy-independent community, suitably modelled and dynamically simulated in TRNSYS environment, with the aim to find out the optimal design and operating values of several key parameters obtained through a comprehensive energy, economic, and environmental analysis. In fact, by means of the developed tool, it is also possible to carry out parametric investigations of the pivotal system parameters in order to optimize different objective functions, i.e. lowest energy consumption, highest renewable energy share, best economic performance, etc.. The potentials and the capabilities of the presented methodology are proved through a real case study analysis focused on the existing agricultural community named “La Bellotta”, located in the North of Italy. This is a livestock farm with a significant renewable energy source; thus, several viable applications based on renewable energy technologies are considered to provide multifunctional benefits for households, community and environment. Such technologies are focused on biogas and biomethane production through the adoption of a biodigester. With the aim of improving the energy efficiency of this community, different proposed system layouts also based on diverse technologies, such as solar thermal collectors, photovoltaic panels, absorption chillers, biomass boilers, etc., have been modelled and investigated, and a comprehensive parametric analysis has been conducted to identify the most convenient system layout, components size, and control logic. Finally, with the aim of further enhance the concept of high energy independent community, district heating and district cooling scenarios are investigated. From the carried-out analysis, interesting energy, economic and environmental results are obtained. The paper provides an example of sustainable design to be performed by means of dynamic simulation, necessary to dynamically evaluate the energy, economic, and environmental performance and potentials of possible measures to be set-up to encourage the use of renewable energy technologies toward a sustainable livestock sector, obtained by preserving the environment and facilitating the implementation of energy efficiency technologies.

In the last years, the International Maritime Organization has been imposing severe and restrictive regulations on pollutant emissions to reduce the environmental impact of modern ships. Thus, the sustainable design of modern cruise ships is crucial to comply with these regulations. In this paper, a novel approach for assessing the potentiality of energy-saving technologies and strategies for ship applications is presented. This approach is based on dynamic simulation, and it is implemented in a suitable tool assembled in TRNSYS environment. Here, the ship-envelope as well as the related ship energy plant systems are modelled and simulated. Also, to consider different ship routes and relative dynamic boundary conditions variations during the cruise, a suitable tool capable of producing customized weather data is developed. To show the effectiveness of the proposed approach, a novel case study is presented. It refers to a modern cruise ship fuelled by liquified natural gas cruising in Norwegian fjords sea. Here, the waste heat of exhaust gases and engine jacket water of LNG engines are exploited to supply different thermally activated devices. Specifically, heat exchangers are adopted for supplying hot water to air-handler units; multi-stage flash distillation systems are adopted for freshwater production whereas steam turbine system, organic Rankine cycle device and molten carbon fuel cells are utilized for electricity production. Suitable control and decision strategies for optimizing the waste heat recovery are implemented. Eight different system layouts are analysed and promising results in terms of primary energy savings (18.1%), avoided pollutants emission (24.4 ktCO2/y, 40.0 tNOx, 90.0 tSOx, 84.0 tPM2.5) and simple payback (0.68 y) are achieved.

This paper focuses on the design of an innovative high-vacuum solar thermal collector, for which a novel dynamic simulation model is developed. As it is well known, standard flat plate solar thermal collectors are affected by thermal losses which significantly reduce their energy performance. Among all thermal losses, convective and radiative account for approximately 80% of the overall. To reduce these losses, a novel innovative flat plate solar thermal collector characterized by a high-vacuum space (i.e. 10-8 mbar) between the glass cover and edge is developed. The vacuum space is made with the aim of insulating the absorber serpentine with a consequent convective thermal loss reduction. In addition, the serpentine absorber system is suitably painted with a solar coating for reducing the radiative thermal loss. Thus, the presented prototype allows store hot water with no need for any additional storage system. In this paper, a mathematical model able to assess the energy performance of the innovative high-vacuum prototype is also presented. The tool is based on a detailed 3D transient finite-difference thermal network and it is validated against the experimental data obtained by different experimental tests.

This paper focuses on the energy performance of smart building façades integrating a novel Concentrating Photovoltaic/Thermal Glazing (CoPVTG) technology. This novel façade technology combines glazing based solar concentrating elements coupled with a PV/Thermal absorber. Specifically, the technology consists of a double-glazing panel, the outside pane is shaped into a series of concentrating lens where a thin layer of PV cells is placed at the focus. Heat is recovered from the back of the PV strings by means of forced air flowing through the cavity, and finally used for space heating or pre-heating purposes. So, while insulating the building thermally, the system can provide solar generated electricity and thermal energy (i.e. recovered air flowing through the cavity of PV/T absorber). With the aim of investigating the passive and active effects due to the integration of this technology in the building façade, a simulation model is developed and implemented in a building energy performance tool, developed in-house and called DETECt. The system, being a multi-functional component, contributes to the electrical and thermal needs of the building, while reducing its heating and cooling needs. Thus, to investigate the potentials of the innovative façade and the developed numerical model, a case study relative to a multi-floor high rise office building, located in several European climate zones, is carried out. A comparative analysis with conventional and semi-transparent PV windows is also conducted. Simulation results show that by using the novel façade system, interesting energy savings can be obtained: the innovative system leads to a remarkable reduction of the final energy consumptions, ranging from 30 to 60% for the investigated weather zones, also toward the nearly or net positive zero energy building goal.

Small islands are usually characterized by high energy demand and no electricity network access with a consequent high fossil fuel energy consumption. This issue could be overcome by increasing the adoption of renewable energy systems and by enhancing the systems’ energy efficiencies. In this framework, the adoption of dynamic simulation and optimization analyses is crucial. For such a reason, in this paper, a novel approach based on dynamic simulation is presented and a suitable case study is conducted. Such an approach is developed with the twofold aim of increasing renewable energy penetration and improving the sustainability of small islands. The convenience in the dynamic simulation adoption is proven by investigating a suitable case study referring to the existing island community of El Hierro. The case study analysis focuses on the feasibility of converting its energy systems into an autonomous one by mixing different renewable-based technologies to traditional ones. The considered polygeneration system includes: i) wind turbines; ii) hydroelectric plants; iii) diesel engines; iv) solar thermal collectors; properly mixed to satisfy the electricity and hot water needs. Furthermore, to identify optimal configurations and maximize the share of renewable energy, a suitable parametric analysis is presented. Also, a hypothetical future scenario characterized by an island population increase is also investigated. Numerical results demonstrate the feasibility of the investigated polygeneration system, as well as the potentiality of the proposed methodology. Specifically, the dynamic simulation approach allows one to determine design criteria and to properly obtain a remarkable increase in terms of renewable energy exploitation and energy independence. In particular, the considered system configuration provides up to 85% of the annual electricity demand and about 82% of the annual thermal energy needs by renewable sources with substantial economic savings.

This paper analyses the energy and economic feasibility of the Building To Vehicle To Building (V2B2) scheme, in which the electricity produced by one building equipped with PV panels is shared to other buildings by means of batteries of plug-in electric vehicles. The proposed approach allows to increase the energy efficiency of buildings toward the nearly Zero Energy Buildings (NZEBs) goal, obtained by exploiting renewable energy which is not produced on-site. The energy and economic convenience of the proposed approach depends on many boundary conditions, such as the weather (solar radiation on PV panels as well as heating/cooling loads), purchasing/selling electricity costs, possible public incentives. To this aim, a dynamic simulation tool, written in MatLab, was developed to carry out comprehensive feasibility analyses on the whole micro-grid system by varying the related main design and operating parameters (e.g. vehicles patterns, battery capacity, solar field size, etc.). To show the capability of the proposed energy management approach, a comprehensive case study analysis, including a parametric analysis for energy and economic optimization purposes, is presented. The modelled scenarios refer to three energy management schemes including two buildings and an electric vehicle. The energy and economic performance of such schemes are simulated for several European locations to consider the influence of the weather conditions (on which building loads and PV production depend) and the electricity market price. Each simulated scenario is compared to a conventional reference one where the novel energy management scheme is not implemented. A comprehensive parametric analysis is finally carried out to identify the optimal systems configurations, which outperform the reference case performance with respect to energy, economic, and sustainability indicators. Preliminary simulation results show that the proposed V2B2 scheme is capable to maximize the self-production and self-consumption of building integrated renewable energy production up to 50%, reducing the grid electricity importation up to 40%.

The Canary Islands have great potential for the implementation of sustainable energy systems due to its availability of natural resources. The archipelago is not connected to the mainland electricity grid and the current generation system is mainly based on traditional fossil fuel. Therefore, the islands strongly dependent on fuel importations, with high costs due to logistics. Furthermore, due to the inadequate coverage of residential heating and cooling needs, the per capita energy consumption is far below the Spanish national average. This occurrence has inspired an intense debate on the current development model of the Canary Archipelago, which has led to the implementation of actions and measures aimed at achieving greater energy sustainability in the archipelago. Furthermore, at a local scale, an important investment plan has been carried out by the Spanish grid operator to ensure energy supply, to improve the system security and reliability, and to optimize the integration of renewable energies. Future measures and investments will be crucial to ensure a sustainable growth, both from the economic and the environment point of views. In this framework, this paper aims to discuss and compare the energy solutions, based on renewable energy technologies, identified to boost the sustainable transition of the islands. To this aim, multiple configurations of a wind power plant coupled with reversible hydro power/storage system for the distributed and on-site energy production in the island of Gran Canaria were modeled, simulated, and optimized by a TRNSYS/Matlab algorithm suitably developed. Specifically, along with the proposed system layouts, different scenarios related to diverse annual costs growth rate of fuel were investigated. The proposed analysis covers a time horizon of 20 years, up to 2040, and aims at assessing the impact of the investigated solution on energy demand, energy supply, and population incomes. Depending on the considered fuel cost growth rate, the best system configurations allow a primary energy saving in the range of 58.1–68.1%. Based on the system choice, the enterprise will generate significant revenues to the island population. The net present values are estimated in the range 1.50 × 103 ÷ 1.84 × 103 and 0.85 × 103 ÷ 1.27 × 103 M€, respectively for the two considered scenarios (annual costs growth rate of fuel 2 and −2%). The analysis demonstrates the importance of investments targeted at the implementation of renewables. The proposed scenarios indicate that the current energy model has the potential to radical change and to tackle climate change and energy issues while producing substantial economic savings and better life conditions for the population in the next years.

This paper presents a novel dynamic simulation model for the analysis of a hybrid turboexpander system coupled with innovative high-vacuum solar thermal collectors. The model is developed in MatLab and it is able to dynamically calculate the energy, exergy, environmental, and economic performances of the investigated system, by taking into account the hourly fluctuation of thermodynamic and economic parameters (e.g. electricity cost, natural gas temperature, and flow rates, etc.). In addition, a computer-based Design of Experiment (DoE) approach was implemented for achieving the optimal design of the proposed system. A suitable case study is presented in order to show the capabilities of the developed simulation tool. Conventional and non-conventional decompression systems located in the weather zone of Messina (South-Italy) are investigated with the aim of assessing the optimal system configuration. By means of the computer-based DoE analysis, the optimal values of several design parameters (such as the number of solar thermal collectors, the volume of the hot water storage tank, and the size of the water loop pump) are calculated. Numerical results show significant primary energy savings (1.36 TWh/year) and avoided carbon dioxide emissions (348 tCO2/year). From the economic point of view, a feasible simple pay-back period of 4.51 years is achieved. The destroyed exergy of the system components are calculated, obtaining the highest value for the turbo-expander, equal to 12.0 TWh/year.

This paper proposes and analyses a novel energy management system for buildings connected in a micro-grid, by considering electric vehicles as active components of such energy scheme. Renewable energy sources, PV, energy storage systems and bidirectional electricity exchange with the buildings and the grid are taken into account. The considered energy scheme, Building to Vehicle to Building, is analysed by including both buildings and mobility consumptions in the energy balance. Three different management system scenarios, designed to analyse the role of electric vehicles as electricity vector among buildings integrating PV panels and electrical storages, are analysed through a case study analysis. To this aim, a dynamic simulation model, implemented in MatLab, is suitably developed for the assessment of the energy demands and loads of the building, as a function of the considered electric vehicles energy use patterns. Simulation results show that the proposed energy management systems improves the building grid reliance and the grid electricity consumption is remarkably reduced up to 45% and 77% depending on the proposed scenarios. Their energy exchange options also enhanced the energy-matching indexes. The economic analysis highlights the economic viability of the system, as well as the need of suitable funding policies to support the development of such micro-grid systems.

Seasonal storage of hydrogen is a valuable option today increasingly considered in order to optimize cogeneration plants under continuous operation in an incentive framework where electricity sale to the national grids is becoming less economically profitable than in the past. The paper concerns the numerical study and optimization of a cogeneration plant installed in an industrial site having an availability of hydrogen over a continuous time scale, to meet the energy needs and mitigating the environmental impact of the plant operation by reducing the energy withdrawal from traditional sources. Two alternatives are analyzed into detail: the former regards energy production through an internal combustion engine, this last properly controlled to be fueled with blends of natural gas and increasing percentages of hydrogen, the latter concerning the addition of fuel cells to the proposed layout to further reduce the electricity integration by the grid. The dynamic response of the cogeneration system under examination is dynamically evaluated to efficiently fulfill the industrial loads to be fulfilled. First, optimization is performed by implementing a PID controller to better track the industrial demand of electric energy. The main results of this solution reveal a −81% reduction of excess electricity, a −7% reduction of natural gas consumed but a 47% raise of CO2 emissions due to the increase in thermal integration. Then, an additional energy generation from fuel cells is assumed. An economic analysis is carried out for each of the implemented configurations. The adoption of fuel cells, despite requiring a greater initial investment, allows obtaining a SPB of 1,4 years (− 16%), 1,17 Mln € of avoided costs (− 18,5%) and 1320 t/year of CO2 emissions avoided (− 95%) with respect to the initial layout.

Nowadays, due to the raising research interest in net and nearly zero-energy concepts at community level, great efforts are spent to investigate self-sustaining and energy-independent communities. Small and off-grid islands represent one of the best places to focus the attention on, and to suit pilot projects of self-sufficient energy communities. In this context, the dynamic simulation represents a useful tool for designing, analysing, and optimizing islands’ energy system layouts, especially in case of renewable energy system adoption (due to the performance unpredictability of renewable energy sources). Therefore, powerful yet flexible dynamic simulation tools are increasingly in demand. In this framework, this paper presents a novel dynamic simulation model, developed in TRNSYS environment, purposely conceived to investigate innovative technologies, novel system layouts, and advanced control logics, in the case of small and off-grid islands, aiming at reaching the nearly/net-zero energy goal at a community level. To prove the potential of the novel dynamic simulation tool, a suitable case study referring to the existing island community of El Hierro (Canary Island) was considered and investigated. Specifically, to enhance the island energy independence, diverse scenarios and system layouts, including different renewable energy based technologies (e.g. wind turbines, hydroelectric power plants, solar thermal collectors, etc.) have been investigated by the novel developed simulation tool. Results demonstrate the potentiality of the adopted method as well as the feasibility of the proposed system layouts. Specifically, the investigated scenarios provide up to 85% of the annual electricity demand and about 79% of the annual thermal energy needs by renewable energy sources with substantial economic savings.

This paper explores the implementation of the Building To Vehicle To Building (V2B2) scheme in European Countries, by evaluating the influence of weather conditions and local energy market prices on its energy and economic performance. The use of electric vehicles as energy vectors among buildings belonging to a virtual cluster is the key aspect of the V2B2 scheme: by exploiting mobile electric storage devices, renewable electricity produced by building integrated PV panels is shared among diverse users and consumed off-site. This novel energy management scheme has a twofold aim: i) promoting energy flexibility and efficiency in multiple buildings by improving the share of self-consumed renewable electricity at a cluster level and ii) reducing the interaction with the power grid. The proposed cluster includes two buildings, a house and an office space, and an electric vehicle, and it can be considered as the basic nucleus of human linked energy users. The energy and economic performance of the proposed V2B2 scheme highly depends on weather conditions and purchasing/selling electricity price. Therefore, to assess the impact of weather and energy prices on the system energy and economic performance, a comprehensive parametric analysis is conducted by varying the main design and operating parameters of the capacity of the key components of the investigated energy cluster, such as of buildings integrating PV panels and electric storage devices. The modelled and simulated scenarios refer to two different layouts simulated in several European cities, selected to consider different weather conditions and national electricity market prices. To identify the optimal V2B2 configurations, several energy and economic indicators of each simulated scenario are compared to a conventional reference one in which the novel energy management scheme is not implemented. Through the proposed V2B2 scheme, encouraging energy savings, from a minimum of 13.6% to a maximum of 71.2%, and economic outcomes are achieved.

This paper presents a novel dynamic simulation tool able to assess and optimize the energy, environmental and economic performance of standard and innovative district heating/cooling systems. To this aim, several design and operating parameters (e.g.: weather conditions, heat selling price for users, national unitary price of electricity, etc.) are dynamically taken into account. The heating and cooling demands and loads of the buildings to be fed by the network working fluid are dynamically calculated. The system pipeline network is modelled through a suitable plug-flow approach. Fluid temperatures are calculated in each network node. The optimization of several system design and operating parameters is achieved for different objective functions. A suitable analysis is considered for selecting the most convenient urban zones for system application. The whole simulation model is implemented in a suitable computer code written in MatLab. By such tool useful design criteria and feasibility analyses can be obtained. To show the capabilities of the presented simulation tool, a novel case study, referred to a district heating system supplied by an existing thermoelectric power plant, was developed. The conducted analysis is based on system optimizations focused on the number of users, the selling heat/electricity prices and system geometric features. As for example, for minimizing the system payback to about 14.0 year, the optimal number of users and network length are 5 × 103 and 2.7 km, respectively. In this case the primary energy savings and the avoided carbon dioxide emissions are about 11.0 GWh/y and 16.1 ktCO2/y, respectively.

An advanced mathematical model capable of simulating the energy performance of an innovative Integrated Collector Storage Solar Water Heater (ICSSWHs) is presented. Usually, ICSSWH devices available in the market are typically simple and low-cost, combining solar heat collection and storage functions in one unified vessel. However, they exhibit higher heat loss characteristics when compared to standard solar collector systems, with a subsequent reduction in energy performance during night-time and non-collecting hours. An innovative ICSSWH prototype was developed at the Centre for Sustainable Technologies (CST) at Ulster University using a patented, innovative thermal diode feature, attained by incorporating a liquid-vapour phase change material (PCM) and very low pressures. In order to fully investigate the energy performance of the proposed prototype, a suitably dynamic simulation model has been developed and validated in MatLab environment. All modelled temperatures are ±1 °C from the respective experimental measurements. The developed model has been used to evaluate the ICSSWH energy performance by varying several pivotal parameters (physical features and materials) in order to produce an optimised device.

Nowadays, energy consumption in the building sector in Europe accounts for 40% of the primary energy needs, being responsible for a significant amount of GHG emissions. Therefore, it is crucial to improve the energy performance of buildings, alongside the utilization of alternative energy sources. On the other hand, the last decade’s financial crisis had an impact on the housing market, resulting housing prefabrication to emerge as a cost and energy-saving solution, which can also be linked to the reduction of environmental impacts as well as to the development of green construction practices. This paper aims to examine the integration of a hybrid photovoltaic/thermal solar system in an energy efficient, environmentally friendly and technologically advanced, prefabricated housing unit. The study focuses on the energy production potential of the active solar system, in relation to the energy requirements of the housing unit, before and after the system’s integration. A dynamic simulation analysis, conducted in the TRNSYS environment, is developed for the energy and economic assessment of the proposed unit. A life cycle cost (LCC) analysis is also performed, in order to determine the viability of the enterprise. The results of the energy simulations and the life cycle cost analysis of the system are intended to demonstrate the impact of the system’s integration on the prefabricated building unit. The originality of the research performed lies on the fact that it offers a novel solution for building integration with the creation of a “plug n’ play” building integrated hybrid solar system for use mostly on prefabricated structures, whilst the LCC comes to cross-check its viability, in terms of real-life applications.

Existing Integrated Collector Storage Solar Water Heaters (ICSSWHs) are typically simple and low-cost devices that combine heat collection and storage functions in one unified vessel. However, during non-collection periods they are affected by higher heat loss characteristics when compared to standard solar collector systems. This paper introduces the design evolution of new horizontal cylindrical ICSSWH prototypes developed at Ulster University that use novel, patented double vessel, thermal diode features (to enhance heat retention during non-collection periods) achieved by incorporating a liquid–vapour phase change material (PCM) with a very low pressure annular cavity. The energy performance evaluation and characterisation of different prototype designs under solar simulated experimental conditions has been conducted and the subsequent parametric analysis presented. A balance between performance and physical/operational considerations is necessary to ensure that new and practical design solutions (in materials, fabrication and assembly) can be formulated to improve the performance of the ICSSWHs within the limits of commercial reality. The importance of augmenting heat transfer across the annulus cavity has been demonstrated with improvement of the cold-start daily collection efficiency from around (ηcol) of 20% (no HTF), to > 55% when the annulus is evacuated to remove non-condensable gases and form a liquid–vapour phase change thermal diode. Annulus thermal diode heat transfer coefficients of around (Ufr) 35 W/m2K in forward mode and 2 W/m2K in reverse mode have been demonstrated. Diurnal thermal efficiencies ( η c o l 24 ) of 22% have been measured, but values of 39% have been identified as achievable in the longer-term development of presented ICSSWH.

The new standards on energy saving for new and existing buildings have animated both researchers and technicians in recent years, aiming at reducing the dependence on fossil fuels, improving indoor comfort, and systems efficiency. In this scenario, special attention must be paid to historical buildings that need to preserve their key testimonial heritage within the society. This paper describes the design and realization stages of a pilot system based on a ground-coupled heat pump, operating both in heating and cooling modes, installed in the monumental site of Saints Marcellino and Festo (SM&F), in Naples, Southern Italy. This study aims to demonstrate that low-enthalpy geothermal systems can be employed as energy retrofit applications in buildings of historical, artistic, and cultural interest and, at the same time, to prove that the use of this technology allows achieving the objectives, set at global level by the current regulations, and requiring a reduction of carbon dioxide emissions (tCO2) of 53% compared to technology using fossil fuels.

This paper presents an innovative Concentrating Glazing system to be adopted in smart building facades: The Concentrating Photovoltaic Glazing system (CoPVG). The device consists of a double-glazing panel integrating a series of concentrating lenses. A thin layer of PV cells is then placed at the lenses' focus. The peculiar lens design can produce, by using the Total Internal Reflection (TIR), a seasonal effect with more light entering the building at low incidence angles (i.e. in the winter months) and higher electricity production at high incidence angles (i.e. in the summer months). To investigate this device's performance, a suitable dynamic simulation tool has been developed in MATLAB environment. Furthermore, to investigate active (electric energy production) and passive (building insulation and solar gains variations) effects related to the building integrated devices, the developed CoPVG simulation tool is implemented in a building energy performance simulation one (DETECt). To show the potential of the innovative device, a case study relative to a multi-floor office building integrating the innovative CoPVG prototype is investigated. Conventional and semi-transparent PV windows are also investigated for comparative purposes. By using the novel facade system, interesting energy savings ranging from 30 to 60 % for the investigated weather zones can be obtained.

Solar heating and cooling systems are a promising technology which may significantly contribute to the reduction of greenhouse gas emissions, the enhancement of energy efficiency, and the increase of renewables share in the building sector. The available literature show a high number of papers aiming at investigating solar heating and cooling systems based on heat driven and solar technologies, configurations, operating strategies, and financing issues. Nevertheless, none of the papers available in literature investigates the possibility to replace conventional solar thermal collectors by flat plat and concentrating photovoltaic/thermal systems, also producing renewable electricity. To cover this lack of knowledge, in this paper a dynamic simulation model of novel solar polygeneration heating and cooling systems is presented. Such dynamic simulation model is developed and implemented in a computer code, written in MatLab, and allows investigating the energy, economic and environmental performance of such novel solar polygeneration systems, based on both adsorption and absorption chiller technologies fed by dish-shaped concentrating and flat photovoltaic/thermal collectors. In order to show the potentiality of the presented tool, a comprehensive parametric case study is carried out to find out the optimal system configurations, as a function of crucial design and operating parameters and of weather conditions. The presented case study analysis refers to a small cluster of four buildings, including office and residential spaces, located in different European weather zones. The modelled solar polygeneration systems simultaneously produce electricity, space heating and cooling, and domestic hot water; electricity is self-consumed or delivered to the electrical grid. For comparative purposes, two different back-up system configurations, based on an electric chiller and a condensing gas-fired heater are also taken into account as conventional reference building-plant systems. By means of this systematic parametric analysis, comprehensive guidelines for system designers, practitioners and/or researchers focused on the development and use of solar heating and cooling systems are provided.

To reduce the environmental impact of modern cruise ships, a crucial role is played by the recovery of waste heat from onboard diesel generators used to balance part of the onboard thermal energy demand. To maximize the recovered waste heat, this paper proposes a novel design methodology for ships energy systems based on the dynamic simulation approach, suitably enhanced to consider moving objects like ships. Through this approach, partial load regimes due to variable energy requirements and the relative response of innovative energy saving technologies are dynamically assessed by properly considering real cruising conditions as a function of the current ship position along its route. To this aim, 3-D ship envelope models, detailed energy ship-plant system layouts, and algorithms for deriving new customized hourly weather data files are suitably developed in MatLab and TRNSYS. To show the capability and potentials of the proposed methodology, a novel case study referred to an LNG-powered cruise ship traveling in the Norwegian fjords sea is presented. Different thermally and electrically activated technologies are coupled in 16 energy ship-plant system layouts, implementing novel controls strategies for optimizing the exploitation of the waste heat recoveries and cold-ironing. Encouraging results are achieved for the best layout, including primary energy savings of 18.1%, avoided pollutants emissions of 24.4 ktCO2/y, 40.0 tNOx/y, 90.0 tSOx/y, 84.0 tPM2.5/y, and a simple payback of 0.68 years. Finally, the proposed methodology represents a step forward toward the modern early design of onboard ship energy systems useful for ship designers, manufacturers, owners and operators.

Worldwide, the design, renovation, and sustainable management of port buildings play a crucial role for sustainability. In this framework, a computer simulation of a building’s thermal behaviour is an almost mandatory tool for making informed decisions. However, the development of a building energy model is a challenging task that could discourage its adoption. A possible solution would be to exploit an existing Building Information Modeling (BIM) model to automatically generate an accurate and flexible Building Energy Modeling (BEM) one. Such a method, which can substantially improve decision-making processes, still presents some issues and needs to be further investigated, as also detectable from the literature on the topic. In this framework, a novel workflow to extrapolate BIM data for energy simulation is proposed and analysed in this paper. Here, the BIM to BEM approach was tested as a useful tool for the maritime industry to improve the implementation of effective energy-saving measures. Specifically, in order to prove the capabilities of the proposed method, a maritime passenger station in Naples was chosen as case study and investigated by comparing different strategies to reduce the annual primary energy consumption. The optimal level of modelling detail required by a trustable building energy assessment was also investigated. By the proposed method, interesting primary energy savings (ranging from 24 to 41%) are achieved and CO2 emissions avoided (ranging from 16 to 34 tons CO2/year) for the investigated building, proving the potential of this approach. Definitely, this paper proves the validity of the proposed methodology and emphasizes its numerous benefits towards the achievements of the most modern sustainability standards.

This work focuses on a dynamic simulation model for the energy, economic and environmental analysis of an innovative polygenerative system layout based on a building integrated photovoltaic thermal system coupled to an adsorption chiller and to an electricity storage system. The thermal energy of building integrated photovoltaic thermal collectors is exploited in order to produce solar space heating and cooling and domestic hot water. Auxiliary electric air-to-water heat pumps/chillers and a gas-fired condensation boiler are included in the system model in order to integrate the demands of heating, cooling and domestic hot water production. The electricity produced by building integrated photovoltaic thermal collectors is used to satisfy the building needs. The eventual extra-production is delivered to the grid or stored in lead-acid batteries. By means of the developed dynamic simulation model (implemented in TRNSYS environment) the energy system performance on the whole building can be analysed in terms of heating/cooling energy, electricity and domestic hot water demands. In particular, both the passive and active energy effects of the investigated collectors can be assessed. The model includes a suitable tool for the comparison of the innovative system layout vs. traditional reference building-plant systems. For energy, economic and environmental impact optimization purposes, sensitivity analyses can be performed by varying the main system design parameters with respect to the value of reference case ones. In order to show the potentiality of the developed simulation model, several new case studies are developed. They refer to a 3-floor office building located in four different Italian weather zones. Simulation results show that the obtained SPBs, the primary energy saving for electricity and domestic hot water production, and the equivalent carbon dioxide avoided emissions range between 10.6–11.3 years, 58.5–68.8% and 76.3–90.2%, respectively.

In this paper a new dynamic simulation model for the building energy performance analysis of multi-enclosed thermal zones, where rigid air temperature and humidity conditions must be kept, is presented. The model was implemented in a suitable computer code (DETECt 2.3.1) developed for research scopes. Such simulation model allows the hygrothermal analysis of buildings with multi-enclosed thermal zones surrounded by larger ones (e.g. display glass cases with valuable artefacts in museum halls, neonatal intensive care units for premature and full-term newborn babies in hospitals wards, etc.). For this purpose, a novel control algorithm, based on a model reference adaptive control scheme, enabling the online adaptation of the control gains, is implemented. Rigid air temperature and humidity conditions can be guaranteed also in case of sudden and rapid variations of hygrothermal loads. Through such new tool innovative techniques and operative strategies for obtaining energy efficiency and indoor comfort of special building spaces can be studied. In order to show the capabilities of the tool and the robustness of the adaptive algorithm, as well as the potentiality of the proposed multidisciplinary approach to the energy-related behaviour in buildings (based on building energy modelling and simulation and control theory), two meaningful case studies have been developed. In particular, they refer to the museums and hospital indoor spaces where enclosed thermal zones have to be kept under stringent hygrothermal conditions.

This paper analyses the energy and economic performance of roof and/or façades Building Integrated flat-plate PhotoVoltaic and Thermal (BIPVT) collectors for residential applications. Aim of the work is to assess the active and passive effects due to the building integration of solar technologies on the building energy consumptions. A comparison among innovative building-plant system configurations, based on BIPVT collectors for the simultaneous production of electricity, thermal energy, and domestic hot water, is carried out. The simulation models of the proposed system layouts are designed and implemented in TRNSYS simulation environment for the dynamic assessment of their energy and economic performance. By means of the developed simulation model, the occurring summer and winter building passive energy effects due to the PVT building integration are also analysed. Several case studies are developed by modelling a representative multi-storey residential building and by considering different European climates. For such case studies a suitable energy parametric analysis is performed by varying the thermal resistances and capacitances of the building envelope. By results interesting design and economic feasibility guidelines are obtained. For the investigated case studies, the pay back periods vary from 11 years for South European weather zones to 20 for North European ones.Several case studies are developed by modelling a representative multi-storey residential building and by taking into account different European climates. For such case studies a suitable energy parametric analysis is performed by varying the thermal resistances and capacitances of the building envelope. By the simulation results interesting design and economic feasibility guidelines are obtained. In particular, by varying the weather location and the building-plant configuration, the adoption of BIPVT panels produces a decrease of the primary energy demands from 67 to 89%. The passive effects of the BIPVT system in both the winter and summer season are also assessed for all the investigated climate zones. The calculated economic profitability resulted slightly better for roof BIPVT panels than for roof and façade applications. For the investigated case studies, the pay back periods appear quite long, varying from 11 years for South European weather zones to 20 for North European ones.

This paper focuses on the experimental validation of a building energy performance simulation tool by means of a comparative analysis between numerical results and measurements obtained on a real test room. The empirical tests were carried out for several months under variable weather conditions and in free-floating indoor temperature regime (switched off HVAC system). Measurements were exploited for validating an in-house simulation tool, implemented in MatLab and called DETECt, developed for dynamically assessing the energy performance of buildings. Results show that simulated indoor air and surface room temperatures resulted in very good agreement with the corresponding experimental data; the detected differences were often lower than 0.5 °C and almost always lower than 1 °C. Very low mean absolute and percentage errors were always achieved. In order to show the capabilities of the developed simulation tool, a suitable case study focused on innovative solar radiation high-reflective coatings, and infrared low-emissivity materials is also presented. The performance of these coatings and materials was investigated through a comparative analysis conducted to evaluate their heating and cooling energy saving potentials. Simulation results, obtained for the real test cell considered as equipped with such innovative coatings and material, show that for the weather zone of Naples a 5% saving is obtained both in summer and in winter by simultaneously adopting a high-reflectance coating and a low- emissivity plaster for roof/external walls and interior walls, respectively.

In this paper the dynamic energy and economic performance of district heating systems is investigated. As well known, such plants can be convenient if thermal energy is available at low costs or as waste heat. Generally, such condition can be obtained in case of proximity of building clusters or town neighbourhoods to thermal power systems, urban waste heat treatment plants or some industry typologies. In this case, through a suitable pipeline network such heat can be supplied to buildings for balancing their heating and cooling demands. In general, the economic profitability of district heating systems depends on different variables, such as for example the unitary cost of heat to be offered to users and the related yearly amount of the sold thermal energy. The system performance is also function of several dynamic parameters such as the weather conditions (influencing the buildings heating/cooling demands). In case of thermal power plants, the related activation typically depends on the hourly national single price of the sold electricity to the grid. In order to take into account all such time dependant variables, a suitable dynamic simulation model for the system energy and economic performance assessments was developed. Such tool is conceived for feasibility analyses of new district heating plants as well as for checking and controlling the existing ones. The model was implemented in a MatLab code where the heating/cooling demands of buildings are dynamically assessed by taking into account suitable hourly weather data files (TMY, IWEC, etc.). A specific subroutine is implemented in the code for the economic optimization of the diameter of each network section. In addition, by the presented computer code the effects on the system performance of the variation of different design and operating parameters can be carried out by varying suitable objective functions. Finally, in order to show the potentiality of the developed simulation tool, a suitable case study is presented. It refers to a district heating hypothesis in the S. Giovanni neighbourhood of Naples (South-Italy). Here, the system is supplied by the heat produced through the thermal power plant of Vigliena in which a novel combined cycle system is currently operating. For such district heating system an energy assessment and an economic feasibility investigation are performed. Furthermore, a system parametric analysis is also carried out for computing the optimal number of district heating users and the optimal selling electricity price with different objective functions, such as: minimum simple and discounted paybacks, maximum net present value and profitability index, maximum primary energy saving and CO2 emission reduction. Useful design criteria and interesting energy and economic results were obtained.

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 CO2 emissions and a simple pay payback period equal to 11.64 years are achieved.

This paper focuses on the design of an innovative low-cost air-based photovoltaic/thermal collector prototype, for which a novel dynamic simulation model is suitably developed in order to investigate its energy performance and economic feasibility under different operating conditions. The main novelty of this photovoltaic/thermal collector is the low-cost heat extraction system, implemented to reduce the photovoltaic cells temperature and to recover thermal energy. The prototype is tested under different operating conditions and the experimental data are used to validate the presented simulation model. The developed tool, implemented in a MatLab code, is used for analysing a suitable case study. The photovoltaic/thermal collectors are coupled to an air-to-air heat pump for space heating of a sample building. A novel performance map of such a coupled system is built with the aim of linking the heat pump coefficient of performance to both the outdoor air temperature and incident solar radiation. In addition, the system energy effectiveness and economic feasibility, compared to those of a traditional system, are assessed for the climate of 8 different European weather zones. Simulation results highlight the effectiveness of the proposed system, estimating primary energy savings (11.0–19.7 MWh/year corresponding to 52–80%), avoided carbon dioxide emissions (4.64–10.4 tCO2/year), and simple pay-back periods (3.2–4.8 years).

AIM • The aim of this guidebook is to develop a basic framework of a design guideline to deliver the most appropriate and costeffective solutions for NZEB in Mediterranean climates. • This guidebook (Part 1) represents specific conditions of Mediterranean climate, aspects related to theoretical background and building envelope design. • Additionally, case studies and a database are described. • Residential buildings are mainly considered in this guide book. CONTENTS 1. Introduction. 2. Challenges to face in a Mediterranean climate. 3. NZEB. 4. General Design Strategies: • Building Envelope Solutions and Technologies; • Opaque Building Envelope; • Transparent Building Envelope; • Shading; • The solutions for opaque components; • Ventilation. 5. Cost effectiveness – optimality. APPENDİX - A. APPENDİX - B. APPENDİX - C. References

This paper presents a detailed exergetic and technoeconomic analysis of a Building Integrated PhotoVoltaic Thermal (BIPVT) system. BIPVT system, consisting of flat-plate PVT solar collectors, is integrated in the south facing facade of a non-residential high-rise building. BIPVT collectors produce: i) thermal energy for space heating purposes, by a radiant floor system; ii) Domestic Hot Water (DHW); iii) electricity. Electric air-to-water heat pumps/chillers and a condensing gas fired boiler are used as auxiliary systems for space heating/cooling and DHW, respectively. In addition, the system also includes an electricity storage system coupled to the BIPVTs in order to mitigate the effects of solar energy intermittency and to obtain a virtually grid-independent system. In order to compare the proposed BIPVT system to a conventional building, a reference building model, i.e. without BIPVTs, energy storage and radiant floor, is considered. Here, the space heating and cooling energy is supplied by air-to-water heat pumps (one for each floor), DHW is produced by a condensing boiler and electricity is supplied by the national grid. The comparison is performed for three thermal zones, well representative of the thermal behaviour of the whole building. In this paper, a detailed dynamic simulation model is developed by means of well-known tool TRNSYS 17, in order to predict the transient behaviour of BIPVT system. Energy and exergy balances are taken into account to determine, for the 1-year operation, the exergy destructions and exergetic efficiencies of each of the investigated components. The economic viability of the proposed system is also discussed and the resulted Simple Pay Back period is about 4 years. From the carried out exergy analysis, the average exergetic efficiency of electricity storage system is about 90%, whereas the condensing boiler one is close to 2% all year long. In addition, an exergy analysis on the proposed BIPVT system located in several European weather zones is also carried out, as well as a suitable exergy analysis is performed by varying the capacity of the electricity storage system. Such analyses aim to assess the weather condition and the size of electricity storage effects on the destroyed exergy and exergetic efficiency of BIPVT collectors and electricity storage, respectively. It resulted that, the highest destroyed exergy of BIPVT occurs in Larnaca (150 MWh/year) vs the lowest one in Belfast (87 MWh/year), whereas the BIPVT collectors exergetic efficiencies range from 8.4% for Larnaca to 8.8% for Belfast.

This paper presents the design and a mathematical simulation model of a novel evacuated flat-plate solar thermal collector prototype. As it is known, for a typical solar thermal collector, the convective heat dissipation accounts for a large percentage of the overall thermal losses. These losses can be reduced by “insulating” the solar absorber with a suitable vacuum space (lower pressure than the atmospheric one) of the collector enclosure. The main problem of this solution is the high initial cost of the modifications required on the structure of the collector envelope (casing and glazing) to withstand the vacuum. Because of the reduced thermal losses, such a system is able to produce relatively high temperatures, compared to normal flat-plate collectors, but also retain their basic advantage which is the fact that there is no need to track the sun like the respective concentrating collectors, which can be used alternatively to produce the same level of temperatures. In this paper, an in-house mathematical model is developed for assessing the energy performance of such technology. A sensitivity analysis on the main parameters affecting the energy efficiency and the working fluid outlet temperature of flat-plate solar thermal collector is also presented. The aim of this analysis is to obtain useful design criteria for the fabrication of a novel evacuated collector prototype. Therefore, construction details about the improved prototype, as well as results about the calculation of the optimal system geometry and the selection of the considered collector materials are provided. In this regard, the description of the attempts carried out to obtain the best design options is also reported. Finally, a comparison between the optimized flat-plate solar collector against a typical one is also presented and encouraging results were achieved.

In this paper the design and the energy performance investigation of a new flat-plate solar thermal air collector prototype is presented. The adoption of cost-effective materials and simple design solutions represent the main novelties of the proposed device when compared to existing commercial collectors. In addition, the prototype is suitably designed to be integrated into the building envelope (facade), which is a key feature for the market uptake of building integrated solar thermal systems. The paper includes the description of the dynamic simulation model, developed for the energy and economic performance analyses of the whole building-prototype system. The simulation model, implemented with a computer code written in MatLab, is able to predict both active (hot air production for building space heating) and passive (winter free heating and summer overheating) effects due to the building integration of the proposed solar collector. By such tool, indoor comfort investigations can also be carried out. The dynamic simulation models of both the building and the collector prototype were successfully validated. In order to show the features of the developed simulation code, a suitable case study was carried out. It refers to an office space, part of a high-rise multi-use building, simulated as located in three different weather zones (Freiburg, Naples and Almeria). The examined solar collector is modelled as vertically integrated into the building facade, and three different orientations (East, South-East and South) were taken into account. Interesting results for the energetic, economic and occupants comfort points of view are obtained. By taking into account an initial cost of the system of about 5 k€, the primary energy savings achieved by the proposed system against the traditional buildings range between 1.9 and 8.0 MWh/y (depending on the selected weather zone and backup system). The shortest payback for all the investigated weather zones is obtained for Naples, which is equal to 6.2 years.

This paper presents an innovative water photovoltaic thermal collector prototype. One of the main novelties of such system is its economic affordability, obtained through low-cost materials. The collector, constructed and experimentally tested at the University of Patras (Greece), is composed of a polycrystalline photovoltaic module coupled to eleven plastic pipes for water heating, located under the PV panel in an aluminium box. The prototype, suitable for building architectonical integration, can provide domestic hot water and electricity to the building. In order to assess the energy, economic and environmental performance of the system under different weather conditions and for diverse building uses, a suitable dynamic simulation model was developed and validated vs. experimental data. To investigate the convenience of the presented prototype and the potentiality of the developed software, a suitable case study is presented. In particular, the photovoltaic thermal collector is coupled to a stratified hot water storage tank for supplying domestic hot water to a single-family house located in three different European weather zones: Freiburg, Naples and Almeria. The system layout optimization was also performed through an energy and economic sensitivity analysis to some design and operating parameters. Useful design criteria and interesting energy and economic results were obtained.

In this chapter, a summary review on a large variety of solar-based thermal energy conversion available technologies are presented. Specifically, the following investigated devices are suitably for the conversion of solar energy to provide heating for the hydrogen production. The chapter is subdivided into three sections. In the introductory section, the classification of the solar thermal collectors is reported. It also gives the definitions of different features characterizing solar thermal devices. Note that, the presented classification is based on these features. The second section gives an analysis of non-concentrator solar thermal collector. Both flat plate and evacuated tube technologies are investigated. Also, it provides information regarding optical and thermal performances of such devices and introduce how they can be physically modeled. In third section, the concentrator solar thermal collectors are introduced. Specifically, the compound parabolic, the parabolic through collectors, the linear Fresnel, and the parabolic dishes are here investigated.

In this chapter, a summary review on a large variety of solar-based thermal energy conversion available technologies are presented. Specifically, the following investigated devices are suitably for the conversion of solar energy to provide heating for the hydrogen production. The chapter is subdivided into three sections. In the introductory section, the classification of the solar thermal collectors is reported. It also gives the definitions of different features characterizing solar thermal devices. Note that, the presented classification is based on these features. The second section gives an analysis of nonconcentrator solar thermal collector. Both flat plate and evacuated tube technologies are investigated. Also, it provides information regarding optical and thermal performances of such devices and introduce how they can be physically modeled. In third section, the concentrator solar thermal collectors are introduced. Specifically, the compound parabolic, the parabolic through collectors, the linear Fresnel, and the parabolic dishes are here investigated.

A novel concept for achieving nearly Zero Energy Buildings (NZEBs) is presented. Here, Renewable Energy Sources (RES) and Electric Vehicles (EVs) are used for obtaining clusters of smart buildings connected in suitable micro-grids. Specifically, the electricity produced by PV panels is stored in EV batteries and suitably dispatched to other buildings or to the national grid. In other words, plug-in electric vehicles are exploited as vector devices for PV electricity exchanges among buildings. Such building energy management approach is called Building To Vehicle To Building (V2B2). For investigating the energy and economic performance of such innovative systems, a new dynamic simulation model, implemented in MatLab, is developed. By such tool a comprehensive parametric analysis on the whole system can be carried out by varying the related main design and operating parameters (e.g. vehicles patterns, battery capacity, solar field size, etc.). In order to show the potentiality of the presented concept, a suitable case study was developed. The analysed new zero energy scheme includes three main electrical users, considered as a basic cluster of human-linked energy systems, such as a residential building, an office building, and an electric vehicle. Energy and economic indexes are used in order to evaluate and compare the effectiveness of different scenarios relative to location of PV and energy storage strategies, simulated and compared to a reference conventional one (without RES). A comprehensive parametric analysis is carried out with the aim to find out the optimal design and operating parameters which maximize the self-production and self-consumption of building integrated RES, toward the achievement of the ZEB goal at a cluster level. Simulation results, carried out for several Mediterranean weather climates, aim to assess the energy and economic feasibility of the proposed concept toward the exploitation of off-site renewable energy production and the reduction of grid electricity needs. Preliminary results show that the building grid reliance is enhanced, the grid electricity consumption is significantly reduced, and interesting energy-matching indexes are obtained.