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The paper presents the design state of a smart car park shelter for electric vehicle in the campus of the University of Palermo. The car park is supplied by the main grid and by a 40 kW photovoltaic system and is equipped with a Li-ion battery storage system with capacity 42 kWh. The hybrid plant is designed in order to operate both in connection with the main grid and in stand-alone mode, supplying, in this case, all car park's loads and providing one recharge to an electric vehicle. Moreover, the energy storage system and, eventually, the battery of one or more cars with V2G technologies, can be managed for providing ancillary services to the grid. In the paper, the design of the system and the choice of all components is presented. Finally, the environmental impact of the diffusion of such installations on the energy system is discussed.

In this paper, a comprehensive review is performed on hybrid systems using electrical Heat Pumps for Heating, Ventilation & Air Conditioning systems and Domestic Hot Water production using case studies from 2016 to 2022. This work particularly focuses on studies that investigated systems with electrical Heat Pumps assisted by a gas boiler. Some studies that considered the exploitation of renewable energy sources, but not as a whole sub-stitute for fossil sources, have also been included. In particular, the analysis investigated the layouts of the systems by considering the type and the size of the components, the control methods applied (by distinguishing rule-based control methods and predictive control methods), and the main performance indices used to calculate energy, exergy, environmental and economic performance. Most of the analysed studies demonstrated that the hybrid systems could be very advantageous if the switch or the integration of the two generators is well managed. Nevertheless, the energy and economic performances are very different for each system studied. They are highly influenced by the control strategies implemented and by the objective functions adopted. Furthermore, climate can influence performance while affecting the Coefficient Of Performance of the heat pump and the availability of energy sources. Regarding economic issues, the systems' performances vary according to specific Country tariff structures. The review reported a promising research activity also pursued by manufacturers of components and equipment. Nevertheless, the paper highlights new possible research and development directions.

Nel 1943 Mario Sironi dipingeva “Il Gasometro”, riprendendo in toni apocalittici il tema del paesaggio urbano. Sono poi passati quasi quaranta anni dall’aprile 1977, mese in cui uscì il numero monografico 135 di “Edilizia Popolare”, con i primi progetti per la riconversione della Bovisa nel quadro di rinnovate relazioni metropolitane; una attenta cronologia metterebbe in luce il ruolo cruciale che quest’area ha giocato nel dibattito sulle forme insediative di Milano e nella più specifica vicenda dell’articolazione territoriale del Politecnico; una lunga storia, dunque, con profondi connotati simbolici e ideologici, che ha visto sedimentare ampio dibattito e vasto patrimonio di conoscenze - oltre a evidenti contraddizioni - dai quali non si può prescindere, ma che vanno tuttavia attualizzati secondo un nuovo punto di vista. Nel progetto per il nuovo insediamento della Bovisa prende corpo il confronto tra due scale, due misure del progetto di architettura. La prima, quella dell’ “idea di città” riferita al principio ordinatore della direttrice nord-ovest; infatti, come già altrove rimarcato, Milano è da sempre città di dimensioni contenute ma di rapporti territoriali estesi, storicamente radicata a un sistema di itinerari e direttrici di lunga e breve distanza, che si riflette nella compresenza delle diverse scale, appunto, con progetti e realizzazioni che evocano i grandi spazi congeniali a questo carattere di portualità. Ma soprattutto, ben al di là delle questioni stilistiche e delle pur notevoli sperimentazioni progettuali che Milano ha proposto, si sottolinea il valore ideologico e dimostrativo di una interpretazione coerente della forma urbis, intesa come espressione originale di civiltà, il cui studio ha valore di principio nell’accezione autenticamente cattaneiana del termine. Così proprio nella dimensione urbana del progetto, si vuole rintracciare anche quel senso di possibilità, quella suscettibilità alle trasformazioni future che nella sola prospettiva locale possono sembrare inattendibili. La seconda misura si ritrova nelle relazioni minute della prossimità, o del “quartiere” nella terminologia del Movimento moderno, fortemente radicata nella municipalità suburbana prima, nel “rione”, poi nella zona del decentramento amministrativo, che per Bovisa continuano a giocare un ruolo di principale importanza. Il progetto seleziona due giaciture che si impongono come generatrici: quella dei campi, occupati poi dalle fabbriche e dalle geometrie dei raccordi ferroviari, che permane entro l’area della “goccia”; quella dell’asse di via Bovisasca, cui si appoggia la maglia regolare del quartiere nel quale, piazzale Bausàn, capolinea delle linee tranviarie, prende carattere di luogo centrale. Il rigore di questa geometria stabilisce l’impianto dell’academical village, riprendendo la definizione e il tipo inaugurati da Thomas Jefferson, impostato sul vuoto del grande spazio rettangolare, con i lati maggiori bordati dagli edifici allineati e aperto sul quarto lato.

Nel progetto per il nuovo insediamento della Bovisa prende corpo il confronto tra due scale, due misure del progetto di architettura. La prime, quella "dell'idea di città" riferita al principio ordinatore della direttrice nord-ovest; infatti, come altrove rimarcato, Milano è da sempre città di dimensioni contenute ma di rapporti territoriali estesi, storicamente radicata a un sistema di itinerari e direttrici di lunga e breve distanza, che si riflette nella compresenza delle diverse scale, appunto, con progetti e realizzazioni che evocano i grandi spazi congeniali a questo carattere di portualità.

Results from the DAYKE-Italy project are presented. An investigation on daylighting in eight classrooms in five Italian universities was carried out through a combined approach: an ad-hoc survey administered to students to investigate how they perceive daylight in classroom, and numerical simulations (DIVA + ALFA) to calculate a set of objective metrics (daylight, circadian, and energy-related). A sample of 542 questionnaires was collected through two sessions and the subjective judgments were correlated to objective metrics. Results from descriptive and statistical analyses showed: (i) the correlation was significant for all daylight metrics: among them, average daylight factor and annual light exposure performed higher correlations compared to daylight autonomy, spatial daylight autonomy and useful daylight illuminance; (ii) rooms with a scarce or an optimal daylight provision (according to standards) were rated with comparable subjective score; (iii) the equivalent melanopic lux showed a higher correlation than daylight metrics based on the horizontal workplane; (iv) energy saving up to 50% can be achieved in the presence of high daylight provision and through daylight responsive controls; however, a relamping of fluorescent systems with LED system is recommended to optimize the consumption; furthermore, estimated saving correlated significantly with objective metrics.

The present work relies on the topic of energy storage for Heat and Electricity applied to Heat Pump Water Heaters coupled with photovoltaic plants for Domestic Hot Water production. The main idea is to evaluate the possibility to exploit the water tank as heat storage for the produced photovoltaic energy and, where appropriate combined with electrical storage. For this reason, two heat pumps with different volume size have been chosen and smart control strategies have been applied while monitoring the water temperature in the tank. Calculations account on tapping profile inferred from monitored data of a representative end-user in a Mediterranean small island. Results show how the combination of smart control strategies and battery systems is the most suitable solution in order to fulfil the domestic hot water energy demand by renewable sources while maintaining comfort requirements.

The achievement of United Nations Sustainable Development Goals, related to energy and resource use, is a critical issue for small and insulated communities. In many minor islands, solar energy is not correctly exploited, and electrical heaters are connected to weak grids with very a high share of generation by fossil fuels. As a consequence, there is the necessity to assess the potential and the suitability of diffusion of alternative systems to avoid dependency on the electrical grid and reduce carbon emissions. This paper aims to evaluate the technical and economic performances of some alternative systems exploiting renewable energy for domestic hot water production. Four different systems were simulated and studied: a heat pump connected to the grid, a heat pump coupled with a photovoltaic plant, a heat pump combined with a solar thermal collector, and a solar thermal plant. Moreover, heat and electricity storages were studied for reducing impacts on the distribution network. The work presents data gathered for a study on energy-retrofit strategies on Lampedusa Island (Italy, 35&deg, 30&prime, 56&Prime, north (N), 568 degree-days). Finally, to select the most cost-effective plant, an economic analysis of the chosen systems was carried out. This analysis shows that the best net present values are associated with the heat pump (HP) coupled with a stand-alone PV system and a small battery and solar thermal-assisted HP. The shortest payback time was calculated for the solar thermal system.

The application of “shiftable” or “modulable” load (i.e. washing machine, dishwasher, etc.) in a Smart Grid, can provide energy saving or modify the power flows in the grid, allowing a reduction of the electrical power peak. This paper explores the possibility to modulate the indoor artificial lighting to support this reduction. The study examines the impact of two different measures of power shaving. On the one hand, the change of Correlated Colour Temperature of the light source, and, on the other hand, the dimming of its luminous flux. The possibility to merge the above-mentioned technical solutions is also analyzed. Based on these strategies, several daily schedules of lighting management are defined, and the corresponding energy saving during some critical time slots are assessed. Results show that in all cases, it is possible to achieve a significant reduction of the absorbed power and a consequent increment of energy savings (up to 59%) also in specific time ranges. Furthermore, considering the application of a Daylight-linked control system, it was observed that power regulation associated with the exploitation of the daylight represents itself a way to dynamically reduce the electric loads on the grid.

Sustainability of energy supply strategies in small islands has been emerging as a severe issue, due to the large margins for improvement and rationalization of the most frequently adopted solutions. In most of the European islands, large amounts of heat are wasted by the operation of engine-based power plants; conversely, heat is produced by boilers (supplied by liquid fuels) or by electric equipment for a number of different uses, like domestic hot water production or space heating in winter. In this paper a techno-economic analysis is proposed to assess the feasibility of CHP-retrofit of the existing power plants and the possible utilization of the recovered heat to supply, via a district heating and/or cooling network, the energy requests of civil energy users (both in the tertiary and in the residential sector). The analysis is accurately performed for six islands located in Italy and characterised by different context conditions from a demographic, geographic and climatic viewpoint, so as to get a comprehensive understanding of the factors that favour/obstruct the economic feasibility of the examined technical solution. As expected, due to the low “linear heat density” usually observed in small islands and to the complex orographic profiles, the investment usually resulted “far from being attractive”; only in the case where public incentive or support mechanism is adopted, the possible integration of the existing power plants with heat recovery devices and a district heating network resulted in moderately attractive, especially in the largest examined islands due to their highest heat loads.

In communities with a high tourist influx and warm climate, such as Mediterranean small islands, the energy demands for space cooling and domestic hot water are expected to significantly increase during summer. Considering the current energy context, for succeeding energy transition and reducing the dependency on not endogenous fossil fuels, it is paramount to increase the deployment of renewable sources of energy, especially wind and solar which, however, are aleatory and unpredictable. Hence, to reduce the high costs for energy supply in these contexts, the analysis of the variation of energy consumption is fundamental. Moreover, mapping the spatial distribution of energy profiles can be useful to have an overview at a large scale of the considered building stock. Within this frame, a Geographic-Information-System-based procedure was implemented to estimate the residential buildings energy demand profiles, focusing on the seasonal variation. The adopted method can provide a valid supporting tool for decision makers that have to implement smart energy strategies in contexts with a high variation of the energy demand and evident electricity summer peaks. The method for mapping the energy demand profiles, implemented on the small island of Pantelleria, can be applied to other similar contexts, also supporting energy policies in the implementation of renewable energy communities.

The study of Demand Response strategies application is widely related to the evaluation of the energy consumption. It is fundamental to optimize the design and management of the plants in the smart buildings. During the design steps, it is necessary to predict the above-mentioned energy consumption. This paper reviews some methods that can be applied to predict energy consumption related to lighting systems. In particular, three categories of methods have been analysed: methods proposed by technical standards, methods based on mathematical indices for daylight assessment, and methods based on simulation models. These methods have been described and applied by calculating the energy consumption by considering a case study plant located at the University of Palermo. Finally, the results of the calculation have been compared with real energy consumption measured in the case study by considering different control strategies in order to underline the criticism of these simplified methods.

The feasibility to shift and/or modulating the loads that characterize buildings can be useful to improve the performance of smart grids. As known, it is not possible to shift in the time the operating time of the lighting system, but it is possible to modulate the needed electric power. In this paper, the first set of data and a preliminary analysis conducted in the Solarlab of the University of Palermo are presented. The innovative lighting system was designed, sized and installed with the aim of evaluating the consumption of an island user that can be controlled by the DSO or an aggregator. In order to do this, the lighting system load was modulated by applying different strategies: varying the Correlated Colour Temperature (CCT), varying the luminous flux, and applying a daylight-linked control system (DLCs). The measurements were taken and also provided useful data to evaluate the real performance of the lighting system and the DLCs. Furthermore, the study focused the attention on the visual comfort parameters. First measurements analysis shows that the strategies applied are useful to modulate the absorbed power and, consequently to be managed and controlled by an aggregator. A variation of absorbed power of the 30% can be achieved by varying the CCT from 3000K to 6000K.

Street lighting plays a crucial role in a city’s night landscape and in urban traffic management, influencing users’ comfort and safety. To contain costs of public street lighting systems and to avoid energy waste, illuminance levels on road surfaces must be adequate to fit actual traffic volumes, as prescribed by regulations. This is true not only for motorized roads but also for sidewalks, paths, and pedestrian areas. Regulations in force establish a relationship between road traffic volumes and minimum illuminance levels through the lighting classes selection procedure. Lighting classes selection is based on various para meters among which traffic volume is the most difficult to evaluate because traffic volumes are generally estimated or measured by a traffic observation campaign. In this paper, an alternative method for classes association which is based on a space syntax approach, is described. The method was applied to the case study town of Pontedera (Italy) for the analysis of the pedestrian and motorized traffic and it shows a good correlation between measured and estimated traffic volumes, demonstrating how the methodology, with a precise and quick estimation of traffic volumes, can help lead to a suitable design of the lighting infrastructure, aiming to reduce energy waste and to avoid oversized lighting systems.

Italy is celebrated in the world for its agri-food industries while the process of production of pasta is highly energy demanding and requires both electrical and thermal energy simultaneously. Because most of the Italian factories producing pasta are located in the Southern part of the country, the direct use of thermal energy generated from the sun would be particularly profitable. In this study, the authors examine the possibility of generating by a Solar Industrial Process Heating plant the thermal energy required annually by an existing factory that produces durum wheat pasta located in Sicily (Italy). The hypothesized plant scheme consists of an array of Fresnel linear solar collectors and a concrete thermal energy storage system in which a heat transfer diathermal fluid circulates. This particular combination, although not the most efficient from the thermodynamic point of view, determines a lower visual impact and easier maintenance during the life span of the system. The use of food graded thermal oil ensures a high level of safety. A TRNSYS model has been developed in order to simulate the energy performance of the above described plant with the aim of optimizing the design of the solar heat for industrial process systems in terms of solar collectors and thermal energy storage dimensions taking into account the available space in the specific location. The obtained results show that the direct use of the thermal energy generated with the Fresnel solar collectors can significantly contribute to increase the sustainability of the most thermal energy-demanding factories working in the food industry, a strategic sector in the Mediterranean Area. The average annual solar contribution can reach about 40% of the total thermal energy requirement, maximizing the solar energy production during the summer season. Moreover, the proposed study allowed the determination of the maximum investment cost of the plant linked to a simple payback time, without external incentives, of 8 years.

The application of Building Automation and Control (BAC) systems has many advantages. One of these is the reduction of the end-user electricity consumption and, if applied to lighting systems, the achievement of well-acknowledged benefits from daylight, such as productivity, health, visual comfort and well-being. Concerning the first aspect, the international Standard EN 15232 proposes the so-called BAC Factors (BF) method to assess the impact of BAC systems on the final energy consumption. The method provides a simplified estimation of the energy savings due to automation in buildings and questions arise on its applicability in some situations. For this reason, the authors have carried out an experimental study aiming at comparing the energy savings calculated using the simplified BAC factor method with those evaluated with a measurement campaign on a laboratory setup. In particular, the BF are evaluated for an office and a residential environment, using sets of data measured in two cases study in South Italy by testing two lighting control systems in different end-uses (residential and office). The comparison between the sets of data shows the limits of the simplified BAC factor method.

Nowadays, the installation of efficient lighting sources and Information and Communications Technologies can provide economic benefits, energy efficiency, and visual comfort requirements. More advantages can be derived if the public lighting infrastructure integrates a smart grid. This study presents an experimental multifunctional infrastructure for public lighting, installed in Palermo. The system is able to provide smart lighting functions (hotspot Wi-Fi, video-surveillances, car and pedestrian access control, car parking monitoring and support for environmental monitoring). A remote control and monitoring platform called “Centro Servizi” processes the information coming from different installations as well as their status in real time, and sends commands to the devices (e.g. to control the luminous flux), each one provided with a machine to machine interface. Data can be reported either on the web or on a customised app. The study has shown the efficient operation of such new infrastructure and its capability to provide new functions and benefits to citizens, tourists, and public administration. Thus, this system represents a starting point for the implementation of many other lighting infrastructure features typical of a “smart city.&rdquo

The paper presents the results of a study carried out on Lampedusa Island (Italy) and based on the survey of electricity consumption data. The main outcomes of the study are: • the characterization of the energy demand of private houses and hotels in Italian small islands with significant touristic flows during the summer period; • the identification of inefficient use of the electric loads; • the construction of aggregated load profiles for clusters of homogeneous domestic end-user to be used for implementing Demand Response strategies. The study shows how electricity consumption in Mediterranean small islands are very high with respect to the national average and lays the basis for future studies on the impact of automation and Renewable Energy Sources on the energy supply-demand sustainability of the island.

The public buildings sector represents one of the most intensive items of EU energy consumption; the application of retrofit solutions in existing buildings is a crucial way to reduce its impact. To facilitate the knowledge of the energy performance of existing non-residential buildings and the choice of the more adequate actions, Public Administrations (PA) should have the availability of proper tools. Within the Italian project "POI 2007-13", a database and a decision support tool, for easy use, even to a non-technical user, have been developed. A large set of data, obtained from the energy audits of 151 existing public buildings located in four regions of South Italy have been analysed, elaborated, and organised in a database. This was used to identify the best architectures of two ANNs and to train them. The first ANN provides the actual energy performance of any building; the second ANN assesses key economic indicators. A decision support tool, based on the use of these ANNs is conceived for a fast prediction of the energy performance of buildings and for a first selection of energy retrofit actions that can be applied.

The European Energy Performance of Buildings Directive (EPBD) recast proposes, a comparative methodology to calculate cost-optimal levels of minimum energy performance requirements for buildings. This paper presents a method able to select the best retrofit action for lighting system, selectively analysing the daylight conditions and applying the cost-optimal methodology for different scenarios proposed for two existing educational buildings located in Italy. With the aim to improve both energy efficient and visual comfort conditions, the retrofit scenarios include lighting solutions with different combinations. They consider the replacement of lamps with more efficient lighting sources and the application of lighting control.

In this paper, we present Overgrid, a fully distributed peer-to-peer (P2P) architecture designed to automatically control and implement distributed demand response (DR) schemes in a community of smart buildings with energy generation and storage capabilities. As overlay networks in communications establish logical links between peers regardless of the physical topology of the network, the Overgrid is able to apply some power balance criteria to its system of buildings, as they belong to a virtual microgrid, regardless of their physical location. We exploit an innovative distributed algorithm, called flow updating, for monitoring the power consumption of the buildings and the number of nodes in the network, proving its applicability in an Overgrid scenario with realistic power profiles and networks of up to 10,000 buildings. To quantify the energy balance capability of Overgrid, we first study the energy characteristics of several types of buildings in our university campus and in an industrial site to accurately provide some reference buildings models. Then, we classify the amount of ``flexible'' energy consumption, i.e., the quota that could be potentially exploited for DR programs. Finally, we validate Overgrid emulating a real P2P network of smart buildings behaving according to our reference models. The experimental results prove the feasibility of our approach.

Purpose The purpose of this paper is to address a project for lighting an old town in Italy. Its originality lies in the holistic approach that aims to fulfil several objectives. One is to reduce energy consumption by using efficient lamps and advanced control systems; the second one is to make the network viable and useful for many purposes by integrating ICT devices; the third one is to provide a new identity to the older part of the city by using new technologies and design concepts; while the last one is to ensure street and pedestrian safety according to codes and standards. Design/methodology/approach The plan of the city of Bagheria and the stock of luminaires of the city are analysed. A multidisciplinary approach has been adopted in order to: analyse the existing lighting infrastructure highlighting critical areas; design a new displacement and select typologies of luminaries able to provide proper light quality and distribution; propose an aesthetic solution and technical design for relevant historical building; and to include in the design process the concept of a new multifunctional pole. Together with an analysis of social benefits, an assessment of economic costs and benefits are discussed. Findings The project allows good energy savings, meets the standard requirements and gives a relevant and strategic improvement in social and environmental management of the city. Originality/value The work provides an example of integrated design of street lighting infrastructures for urban renovation in old cities in degraded environments.

The paper aims at exploring the performances of a compact Desiccant Evaporative Cooling system called “Freescoo” (Free Solar Cooling) in comparison to standard conventional technologies. The Freescoo – that aims at applications in the residential sector and in small office buildings and includes a photovoltaic–thermal system – is analyzed, its monitored performance discussed and reported: under cooling conditions an Energy Efficiency Ratio of 12.8 is calculated, that reaches 50.7 if also photovoltaic generation is considered. To assess the performance of the proposed system a Life Cycle Assessment study was performed to investigate the system covering all its life, from the production, going through its use and its disposal. Results are compared to those obtainable by standard conventional systems with comparable heating and cooling power outputs to further explore the performances of the system. The electricity consumption of the investigated solar cooling system proves to be equal to only the 5% of the equivalent conventional system having the same thermal output during a year. The production phase of the Freescoo shows a predominant role among the other life cycle steps, reaching a 95% share on the total for some indicators, such as human toxicity. If the life cycle phase of a conventional system is compared with the whole life cycle of the Freescoo system, the former would report many indicators values higher by 200% in comparison to the latter. If use of water is considered, although the Freescoo system would require 2590 l of fresh water during a year in comparison to none consumed by a conventional system, the higher water footprint of conventional systems would result in water uses higher by three times if compared to the Freescoo.

The aim of this work is to compare the performance of a daylight-linked control system installed and tested in two different case studies by means of a set of indices. The two case studies are characterized by different geometry, location and windows orientation. The first one is located at the ENEA premises in Lampedusa (IT, 35° 30' N); the second one is located in Palermo (IT, 38°6' N) on the third floor of the building 9 of the Department of Engineering if the University of Palermo. In both cases, the indices were calculated by using the same daylight-linked control system and the same end-use (office). The results were reported and analysed in order to demonstrate as the performances of the control system can be different from the ideal performance and that they can be different according to the installation. Furthermore, according to the first outcomes, it results that a detailed analysis of the space before the installation of the control system is a necessary practice.

Solar heating and cooling systems are reliable and feasible solutions among renewable energy technologies. Indeed, solar thermal devices help reduce primary energy consumption and can reduce electricity demand, thus representing one of the best options for satisfying heating and/or cooling energy supply. The Borehole Thermal Energy Storage (BTES) represents one of the best promising option among the various storage technologies, because the size of the storage can be easily extended by drilling additional boreholes and simply connecting the pipes to the existing boreholes; the overall energy efficiency of this system is about 40–60%. In this paper, the authors present an application of this technology for the heating system of a school building located in the Southern part of Italy. Two different energy schemes are presented: a school equipped with a conventional gas boiler system with radiators and the same school building with a low temperature heat pump system with fan-coils. All simulations were performed in dynamic state by using TRNSYS software. The results of the analysis assessing the energy and economic performances of the two systems highlighting the advantages of the BTES application in the context of Italian market.

This work addresses the energy saving performances of some solar Desiccant and Evaporative Cooling (DEC) systems working with the freescoo technology. The innovative freescoo concept is based on the use two fixed and cooled adsorption beds and advanced indirect evaporative cooling processes. The main feature of this new adsorption bed concept is to allow the simultaneous dehumidification and cooling of air. The systems analyzed have been installed in Italy last here and results based on field monitoring data are here presented. A description of the monitored systems and comparisons between the energy performances based on the main performance indicators such as EER, thermal COP, cooling power, off grid operation data are shown. Systems are provided with solar PVT collectors which produce the necessary heat for the regeneration of the desiccant and fulfil most of the need of electricity.

This paper presents a user-friendly Life Cycle Assessment tool, which aims to support researchers, designers and decision-makers in evaluating the life cycle energy and environmental advantages related to the use of solar heating and cooling (SHC) systems in substitution of conventional ones, considering specific climatic conditions and building loads. The tool was developed within the Task 48 “Quality Assurance & Support Measures for Solar Cooling Systems”, promoted by the International Energy Agency in the framework of the SHC Programme.

Existing street lighting systems, in most of South Italy cities, are often inefficient due to the obsolescence of lamps and luminaires and of ineffective light control systems unable to implement efficient on-off and dimming strategies. Energy efficiency improvement, in street lighting systems, is often one of the key actions to be adopted by Public Administration in their Sustainable Energy Action Plan in the framework of the “Covenant of Majors” activities. As a task of FACTOR 20 project, a set of planning options has been analysed and proposed. Particularly, street lighting efficiency projects have been studied for representative case studies. A detailed survey of the public lighting systems, in Comiso, allowed represent current performance figures such us installed power, luminance and illuminance levels in roads categories, electricity consumption, switching and dimming schedules. A project of system upgrade has been elaborated. To do this, many lighting simulations, energy and economic assessments in three scenarios have been performed. The obtained results show that high improvements of the lighting quality are foreseeable together with large energy and economic saving. An economic sensitivity analysis, has shown how the performance can change. The proposed methodology can be applied in many similar South Italy cities.

The design and operation of multifunctional infrastructures for public lighting as well as their impact on the urban environment and citizens’ life is today of great interest. The cost of energy for public lighting is often an issue for the budget of municipalities. Furthermore, researchers’ and designers’ attention is increasingly focused on aspects of public lighting not directly valuable through economic factors. Starting from the “quality” of the light environment, looking at citizens’ visual comfort, the light has to be considered as an instrument to improve the urban context and objects therein (including buildings). Indeed, urban degradation (lack of infrastructures, maintenance, services, etc.) is linked to the poor quality of everyday issues, such as traffic, pollution, noise, lack of information, long times to access focal points, and the lack of safety. Simultaneously, in many areas, the potential related to the valorization of historical heritage is often underexploited. The installation of efficient lighting systems coupled with the implementation of ICT solutions can provide economic, social, and health benefits, energy efficiency, and visual comfort. On the other hand, as for indoor lighting, these systems can be expensive, not easy to maintain, and not as efficient as expected. The aim of this Special Issue was to investigate the problems and advantages of smart urban lighting systems in more detail. This Special Issue included 6 papers of the 10 submitted papers.

This paper proposes a study about the feasibility to modulate the indoor artificial lighting, taking into account both achievable energy savings and comfort conditions, in order to reduce lighting electric loads. In particular, it focuses on the possibility, on one hand, to decrease the luminous flux and, on the other hand, to change the Correlated Colour Temperature (CCT), in order to decrease the absorbed power. Moreover, the impact of daylight-linked control systems was considered. Finally, the possibility to combine the different technical solutions was analysed. The paper proposes the definition of daily scheduling referred to lighting energy management, in order to modulate the maximum load value, maintaining a minimum during the rest of the time for an office end use.

Tourist activity strongly influences the energy consumption and the overall load profile of communities with isolated energy systems. One example is hotel sectors on small islands that are not connected to mainland energy distribution grids. The use of solar energy systems could be a smart option for reducing energy consumption and tackling seasonal fluctuation. The operation of a weak and isolated electric grid requires attention to the management of power profiles in very short time frames. Energy storage (thermal or electric), as well as building automation control technologies, can be utilised for these aims. In this context, the present paper illustrates a study conducted at a hotel located on Lampedusa Island (Italy) that was considering some energy-retrofit scenarios dealing with the exploitation of renewable energy sources and building automation control technologies. The hotel is equipped with an air-to-water heat pump able to fulfil air conditioning and domestic hot water demands. Data concerning the hotel's energy consumption was measured during summer months while yearly data was provided by the local electric utility company. Detailed simulation models have been validated by this data and used to assess the efficacy of retrofit scenarios and their effects on the average daily electric profile.

Sustainable urban development, especially in disadvantaged regions, has increasingly gained a major strategic priority. New settlements and urban regeneration programs have to achieve an improvement of social life quality, promote economic growth and increase environmental protection practices and proper use of local resources. In this framework, building environment development must exploit natural resources with responsible approach by using local materials and traditional techniques. In this end, indoor comfort and energy consumption have to match the territories needs. Low energy and passive heating/cooling techniques should be considered as a valid option in many building projects. The paper reviews some models evaluating thermohygrometric comfort in natural ventilated buildings, based on adaptive approaches. A focus is given on Mozambican building traditions, and, finally it proposes a case study where, by the recovery of Mozambican old traditions, a new healthcare facility is designed to be energy autonomous also including large use of natural ventilation.

Artificial lighting systems have to ensure appropriate illuminance with high energy efficiency according to best design practice and technical standards. These aims can be tackled, by incorporating a Daylight linked control system. However, the system behaviour is strongly influenced by several factors and, in particular, by the sensors' position. Indeed, very often the illuminance on work-plane is not fully correlated with illuminance measured by the photo-sensor used to control the luminaires. This fact leads to wrong information for the Daylight linked control systems affecting its efficacy. The artificial intelligence of Neural Networks can be exploited to provide a method for finding good relationships between the illuminance on workplane and the one measured in another surface. Artificial Neural Networks are able to process complex data set and to give as output the illuminance in a point. By the use of measured values in an experimental set up, the output of several Artificial Neural Networks related to different sensors placements have been analysed. In this way it was possible to find the position of the photo-sensor associated to the best forecast of the workplane illuminance with a mean square error of 2.20 E−3 and R2 of 0.9583.

The BAC factors method was introduced by the international Standard EN 15232 for a rough evaluation of energy savings in buildings obtained thanks to automation. The above standard considers the building's services such as heating, cooling, ventilation and lighting and takes into account automation on the basis of assumed usage profile for the related technical installations. However, the standard does not refer specifically to the automation of outdoor lighting systems such as those serving gardens, entrance walkways and passages around the building and supplied by it. In this paper, the authors propose a method for evaluation an outdoor BAC factor for lighting system considering various scenarios. The method can be seen as a possible extension of the one proposed by EN 15232 and can be used with the same purposes.

The purpose of this study was to assess an energy retrofit of a building representative of those in public tertiary stock, to improve energy performance toward nearly Zero-Energy Building (nZEB) requirements. The building is located in the campus of the Politecnico di Milano University (Italy). Several hypothetical improvements regarding the building envelope and plants were assessed in terms of energy savings, costs, and the reduction of greenhouse gas emissions. The results of the study show that it is possible to reduce primary energy demand and associated emissions up to 40% from the current values by adopting market-available and well-proven technological solutions for retrofit. Moreover, exploiting on-site renewable energy sources, the net energy consumption can be near zero. However, an economic analysis of the application of these technologies has highlighted many critical elements related to the implementation of some solutions. This is particularly true for actions related to the thermal insulation of the building envelope and to the installation of ventilation system with heat recovery. Since nZEB requirements are related to the concept of economic performance, this paper gives useful hints to better understand the viability of many commonly adopted actions and strategies for reaching such targets in building retrofit cases.

Solar heating and cooling systems for space heating and cooling are experiencing a growing trend and interest. However, the actual energy and environmental performance of small/medium size installations is not clearly foreseeable. In this paper, an analysis of such systems using adsorption chillers in different European climates is presented. Solar systems have been simulated in TRNSYS and compared to a conventional system employing a vapour compression unit. The results have been used for a Life Cycle Assessment (LCA) study, determining the potential impact during the whole life of the system, from raw materials supply to its end-of-life. The LCA has been carried out by using the LCA tool developed in the framework of the International Energy Agency SHC Task 48. Results showed that the useful life of the system is a key parameter: for a useful life of 10 years, the conventional system performs better than the renewable-based one for almost all the locations. However, if a longer life is achieved (15 or 20 years), solar systems show environmental advantage under almost all the climatic conditions: the environmental benefits of using a solar system during the operation step counterbalance the additional impact generated during the other life-cycle steps.

L'edilizia è uno dei settori più rilevanti in termini di produzione di ricchezza e di occupazione, ma è anche responsabile di significati consumi di risorse naturali e impatti ambientali. SI stima, infatti, che nell'Unione Europea l'edilizia sia responsabile del 50/60 % del consumo di risorse naturali, e tali percentuali difficilmente decresceranno senza l'avvio di strategie e azioni orientate alla riduzione dei consumi di combustibili fossili e all'aumento dell'impiego delle risorse rinnovabili.

Daylight access and indoor thermal comfort are key issues for high design level of sustainable buildings. In fact, daylight provides energy savings and visual comfort condition that can foster higher productivity and performance. This paper proposes a case study of sizing of daylight devices for zenith light. It enables the decision-making process of the designer to reach high levels of daylight factor. The proposed method is shown with an example of application. For the case study, a room in south of Italy, 24 different solar tunnels configurations and 12 cases with different number of skylights have been evaluated.

The installation of Building Automation Control Systems (BACs) in general is an effective action to achieve relevant energy savings. Commercial BACs, installed in residential or small offices, often include functions of lighting control, acting as Daylight-Linked Control Systems (DLCSs). Nevertheless, because system performance is strictly dependent on different parameters, BAC’s hardware and software configuration and as well as an inaccurate commissioning do not always allow a perfect execution of the desired tasks; therefore, the system could not work as expected. Moreover, it is well known that energy saving potential is specifically related to the variability of the light environment. Although many methods to assess it are available, these are mainly based on average data, tabular factors, and climate/lighting time series embedded in weather files used in detailed simulations and, in general, they adopt as a benchmark the performance of ideal control systems. In this paper, actual performances of a daylight-linked control system have been evaluated by a set of indices which, in general, can be calculated, after measurement, during the commissioning stage or in periodic monitoring of the system. In particular, these indices take into account the excess and the deficiency of illuminance over time with respect to a target set point that a lighting system should provide and the related energy consumption. The indices have been tested using data measured in a laboratory set up where a commercial daylight-linked control system, working not close to an ideal one, is installed and has been evaluated for different end uses, operating schedules, control strategy (dimming and ON/OFF) and daylight conditions. Finally, useful relations between system performance and environmental conditions have been found.

In the last few years, many buildings have been equipped with Building Automation and Control (BAC) systems. BAC systems can be used to achieve a significant reduction of the electrical consumption and to have all the well acknowledged benefits from the daylight (e.g. occupant comfort, health, well-being and productivity). For this reason, Standard EN 15232 "Energy performance of buildings — Impact of Building Automation, Controls and Building Management" puts into evidence the importance of the presence of BAC and Technical Building Management (TBM) systems, suggests a classification of these systems, explains their main functionalities and presents a simplified method to estimate their impact on the energy consumption of the building. The aim of this paper is to verify this simplified BAC factor method using the results of an experimental measurements campaign. In the paper, the BAC factors are evaluated for a residential and an office environment, using a big set of data measured for one year every 5 minutes at the laboratory of the DEIM (University of Palermo), where a BACs for lighting control is installed.

In the framework of the Italian R&D project i-Next two pilots plants were realized aiming at demonstrate benefits coming from the adoption of electrochemical energy storages (Lithium ion batteries and hydrogen) integrated with renewable energy sources. In the present study the preliminary results coming from the demo sites operations are reported paying attention to the impacts to the grid.

The paper addresses the issue of the transition from a traditional electrical system without automation to a newer active and smart system allowing the possibility of implementing Demand Side Management policies, for little islands not supplied by the main grid. In particular, the paper focuses on two main topics related to the definition of: • an effective control, monitoring and communication system as a tool for the full exploitation of the opportunities given by Demand Response policies; • some solutions for the automation of the end-users’ electrical installations, in order to offer to the utility flexibility to be used for the improvement of the generation and distribution efficiency. After a brief discussion on the international regulatory framework on automation and ICT applications for power systems, the paper presents a feasibility study, based on the characteristics of the island of Lampedusa, of a hierarchical architecture of a suitable control system and of some DSM enabling solutions for residential end-users. The proposed solutions are defined taking into account some main elements: • distribution grids in small islands are generally equipped with outdated and hardly automatable devices; • utilities in small islands have reduced budget for new investments; • not less important, the most of the inhabitants has low income and unfamiliarity with automation. Therefore, main features of the proposed DSM enabling technologies are low cost and ease of use.

Starting from the results of a Life Cycle Assessment of small solar assisted heat driven chillers, the application of such methodology has been extended to systems with a conventional compression chiller assisted by a photovoltaic plant (PV). This study aims to provide a comprehensive compared investigation of these two families of solar assisted cooling systems (with solar thermal or PV). Results indicate that, in many cases, the systems with the PV grid connected plant performed best. In addition, two more configurations were investigated to further define the PV assisted systems, which minimise their interaction with the grid through the use of electricity storages. These systems performed worse than the PV grid connected systems and the solar thermal assisted systems in nearly all the analysed cases. 2013 Elsevier Ltd. All rights reserved.

When a building undergoes a retrofit project, the goal of assessing energy and environmental performances of retrofit actions is a complex matter. Building and its environment are complex systems in which all sub-systems are strongly interdependent and influence the overall efficiency performance. In the following paper, starting from a literature review of building life-cycle studies, the authors highlight that there is a strong interplay among all the phases of a building life-cycle, as each one can affect one or more of the others. In detail, starting from the results of a “cradle to grave” life cycle study of an existing Mediterranean single-family house, a set of retrofit actions voted to reduce the energy consumption during the operation is analysed. The proposed actions are addressed to improve the thermal performance of the building envelope and the energy efficiency of technical equipment. Performance assessment of these actions has been carried out not only considering the related effects on energy saving for building operation, but also taking into account other phases of the life cycles. In fact, these measures will cause an increase in the building embodied energy, which is the energy embedded in building materials, utilised in transportation and construction processes, in maintenance and demolition. Thus, a balance between the energy saving during operation and the avoided environmental benefits due to the other phases has been done. In particular, the embodied energy and the environmental impacts related to production, transportation and installation phases of the required material/components for retrofit implementation are assessed. In other terms, LCA allows to estimate the reduction of the operation energy and the increase of the embodied energy within the building life-cycle, and to understand whether the achieved energy benefits could be supported in a life cycle perspective or were overcome by the environmental burdens of the actions.

Currently, many effort have been done to enable energy saving issues in building design and many definitions have been introduced for most performing constructions based on energy balance between energy demand and supply. Recently, the Net Zero Energy Building theory has bypassed old Passive House concept but many questions still remain open. Present work aims to estimate how NZEB requirements matching could be affected by the choice of their definition and the choice of weighting factor system, to be count in the energy balance. NZEB concept is mainly referred to new buildings design. Its application to existing buildings is for sure an hard task provided the architecture and physical constraints are often problematic. Nevertheless, the benchmarking approach able to assess the building performance according to the NZEB objective can be utilized for other two purposes. The first one is to assess how an existing building is far from the performances of a NZEB. The second one is to assess the contribution of a conventional retrofit in improving its energy balance.

The cost effectiveness of micro-wind technology is closely linked to the annual energy production plants, which strongly depends on the wind characteristics and on the morphological properties of the installation site. The power curve of a wind turbine, supplied by manufacturers, characterizes the theoretical energy performance that it should have at a particular site. The behavior of a wind turbine in the field is affected by the speed but also by wind direction variations. At each change of direction and speed, the turbine will try to adapt to new conditions and the phase transition negatively influences the energy production. In order to experimentally confirm what above mentioned, the authors have built up a test facility and started a monitoring campaign in the urban area of Palermo. In particular, a micro wind turbine and a weather station were installed at the solar laboratory of DEIM. Thanks to data monitoring was possible a climate characterization of the site, and the evaluation of the experimental power curve of the turbine. The experimental data were discussed and compared to the manufactured data.

Life Cycle Assessment (LCA) is an effective methodology to assess the energy and environmental impacts of energy systems during their life cycle, including manufacturing, operation and end-of-life. The aim of the paper is the application of a simplified LCA tool, developed in the framework of the International Energy Agency Solar Heating and Cooling Task 48, for comparing different typologies of solar assisted heating and cooling systems. In detail, solar thermal heating and cooling systems located in Palermo (southern Italy) and in Zurich (Switzerland) were compared with conventional systems assisted by grid connected and stand-alone photovoltaic plants. A validation of the tool was also carried out by comparing the obtained results with those of in-depth LCA studies. The results showed that the best system configuration in Palermo is the conventional system assisted by a grid-connected photovoltaic plant. Its impact on global energy requirement is about 83.7% and 74.5% of the corresponding impact of the solar thermal heating and cooling and the conventional system assisted by a stand-alone photovoltaic system, respectively. Different considerations can be made for Zurich, where the solar heating and cooling system performs better than the others; it is characterized by a global energy requirement that is 85.3% and 81.2% of the grid-connected and stand-alone photovoltaic assisted conventional systems, respectively. A similar trend is traceable for the global warming potential indicator. The validation of the LCA tool proved it to be reliable since deviations with a detailed LCA of the same system are contained below a 5% difference in all the comparable systems.

The public buildings sector represents one of the most intensive items of EU energy consumption; the application of retrofit solutions in existing buildings is a crucial way to reduce its impact. To facilitate the knowledge of the energy performance of the existing non-residential buildings and the choice of the more adequate actions, Public Administrations (PA) should have the availability of proper tools. Within the Italian project “POI 2007-13”, a database and a decision support tool, for easy use, even to a non-technical user, have been developed. A large set of data, obtained from the energy audits of 151 existing public buildings located in four regions of South of Italy have been analysed, elaborated and organized in a database. This has been used to identify the best architectures of two ANNs and to train them. The first ANN provides the actual energy performance of any building; the second ANN assesses key economic indicators. A decision support tool, based on the use of these ANNs is conceived for a fast prediction of the energy performance of buildings and for a first selection of energy retrofit actions, which can be applied.

Present work deals with the topic of building integration of solar thermal collector (BIST) as a refurbishment measure. Such equipment, more than its main function as heating generator, plays a specific role as a building component (envelope finishes, thermal insulation layer, roof cover etc). Consequently, from a heat transfer point of view, an integrated component affects twice the global building balance: supporting the thermal plant (i.e. providing heat for final uses) and modifying the wall heat-transfer pattern (i.e. reducing thermal losses). In turn, the collector performance itself is influenced by the wall structure (back losses reduction). Present work proposes a method for evaluating the yearly performance of a low cost BIST by means of a Trnsys model on a reference building. This model arises from previous studies based on experimental validation of a FEM model that was implemented in order to describe the collector-wall system efficiency.