0000000000037594
AUTHOR
V. Lo Brano
A set of indices to assess the real performance of daylight-linked control systems
Abstract 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 envi…
Optimization of trigeneration systems by Mathematical Programming: Influence of plant scheme and boundary conditions
Abstract The large potential for energy saving by cogeneration and trigeneration in the building sector is scarcely exploited due to a number of obstacles in making the investments attractive. The analyst often encounters difficulties in identifying optimal design and operation strategies, since a number of factors, either endogenous (i.e. related with the energy load profiles) and exogenous (i.e. related with external conditions like energy prices and support mechanisms), influence the economic viability. In this paper a decision tool is adopted, which represents an upgrade of a software analyzed in previous papers; the tool simultaneously optimizes the plant lay-out, the sizes of the main…
Artificial Neural Networks to assess energy and environmental performance of buildings: An Italian case study
Abstract Approximately 40% of the European energy consumption and a large proportion of environmental impacts are related to the building sector. However, the selection of adequate and correct designs can provide considerable energy savings and reduce environmental impacts. To achieve this objective, a simultaneous energy and environmental assessment of a building's life cycle is necessary. To date, the resolution of this complex problem is entrusted to numerous software and calculation algorithms that are often complex to use. They involve long diagnosis phases and are characterised by the lack of a common language. Despite the efforts by the scientific community in the building sector, th…
Regression analysis to design a solar thermal collector for occasional use
Abstract Optimal design of a solar thermal system is necessary to minimize payback time and to diffuse renewable energy use for Domestic Hot Water production in residential areas. More accurate design is crucial in the case of seasonal or occasional use of the system; indeed, the standard criteria generally applied to a design system for continuous use, can lead to considerable over-sizing. To speed up the design phase and to help the planner in the identification of the best solution without any complex evaluation or long computational time, it would be interesting to have available a simpler method than the standard procedures, but one that is reliable and accurate for the evaluation of t…
Short-term prediction of household electricity consumption: assessing weather sensitivity in a Mediterranean area
Abstract Urban microclimatic variations, along with a rapid reduction of unit cost of air-conditioning (AC) equipments, can be addressed as some of the main causes of the raising residential energy demand in the more developed countries. This paper presents a forecasting model based on an Elman artificial neural network (ANN) for the short-time prediction of the household electricity consumption related to a suburban area. Due to the lack of information about the real penetration of electric appliances in the investigated area and their utilization profiles it was not possible to implement a statistical model to define the weather and climate sensitivities of appliance energy consumption. F…
Application of optimized artificial intelligence algorithm to evaluate the heating energy demand of non-residential buildings at European level
Abstract A reliable preliminary forecast of heating energy demand of a building by using a detailed dynamic simulation software typically requires an in-depth knowledge of the thermal balance, several input data and a very skilled user. The authors will describe how to use Artificial Neural Networks to predict the demand for thermal energy linked to the winter climatization of non-residential buildings. To train the neural network it was necessary to develop an accurate energy database that represents the basis of the training of a specific Artificial Neural Networks. Data came from detailed dynamic simulations performed in the TRNSYS environment. The models were built according to the stan…
The environmental product declaration EPD with a particular application to a solar thermal collector
The principles of sustainable development and of Integrated Product Policy are applied in new voluntary regulations, which have been internationally agree. The aim is to grant transparency of environmental information and to promote the diffusion of environmentally friendly products. A new tool under study is the Environmental Product Declaration (EPD), a technical paper annexed to products that synthesises their energy and environmental performances. This paper points out the reasons for developing EPD for the energy sector, and puts special focus upon renewable energy systems, products whose environmental performances are often not clearly defined. We describe how results of a LCA upon a …
The redesign of an Italian building to reach net zero energy performances: A case study of the SHC Task 40 - ECBCS Annex 52
In the framework of international actions to reduce the energy requirements and greenhouse gases emissions due to buildings, a new International Energy Agency task has been recently established in order to study Net Zero Energy Buildings (NZEBs). The commonly shared concept of NZEB, is a building whose annual balance of energy consumptions tends to zero. This concept is still too imprecise and the authors of this paper participate to the activities of SubTask B of IEA Task40 with the aim of establishing an internationally agreed understanding on NZEBs. The task is based on a common methodology for identifying and refining design approaches and tools to support industry adoption of innovativ…
Experimental validation of the BAC factor method for lighting systems
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 im…
A solar assisted seasonal borehole thermal energy system for a non-residential building in the Mediterranean area
Abstract 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 applicatio…
Modelling and analysis of real-world wind turbine power curves: Assessing deviations from nominal curve by neural networks
Abstract The power curve of a wind turbine describes the generated power versus instantaneous wind speed. Assessing wind turbine performance under laboratory ideal conditions will always tend to be optimistic and rarely reflects how the turbine actually behaves in a real situation. Occasionally, some aerogenerators produce significantly different from nominal power curve, causing economic losses to the promoters of the investment. Our research aims to model actual wind turbine power curve and its variation from nominal power curve. The study was carried out in three different phases starting from wind speed and related power production data of a Senvion MM92 aero-generator with a rated powe…
A methodology for optimisation of solar dish-Stirling systems size, based on the local frequency distribution of direct normal irradiance
Abstract In geographical areas where direct solar irradiation levels are relatively high, concentrated solar energy systems are one of the most promising green energy technologies. Dish-Stirling systems are those that achieve the highest levels of solar-to-electric conversion efficiency, and yet they are still among the least common commercially available technologies. This paper focuses on a strategy aimed at promoting greater diffusion of dish-Stirling systems, which involves optimizing the size of the collector aperture area based on the hourly frequency distributions of beam irradiance and defining a new incentive scheme with a feed-in tariff that is variable with the installed costs of…
Energy saving and user satisfaction for a new advanced public lighting system
Abstract The retrofit of urban lighting systems is often an advantageous means of achieving notable energy savings and improvements in the quality of light. User habits, expectations and lifestyle can contribute to the design of these systems, for example in deciding on the most appropriate control strategies or the light quality. The influence of such variables can be extended to the overall system performance. This paper presents a method of street lighting design based on two kinds of analysis carried out in a defined test area: measurements (by means of a monitoring study) and user preferences (by means of a survey). The results of this data analysis create the basis for the final desig…
Life Cycle Sustainability Assessment of a dish-Stirling Concentrating Solar Power Plant in the Mediterranean area
Abstract Among the different renewable energy sources, solar energy shows the highest exploitation potential to satisfy a substantial portion of the worlds’ future energy demand, guaranteeing at the same time lower emissions than conventional energy providers. Much of this potential is usable thanks to Concentrating Solar Power (CSP) technologies, of which the dish-Stirling concentrator is the most efficient. Nevertheless, the production and installation phases of the dish-Stirling technology can have an environmental impact which motivated the assessment of the plant in the three dimensions of sustainability (environmental, economic and social). The present publication evaluated an existin…
Set up of a monitoring system for a preliminary evaluation of the Urban Heat Island in the town of Palermo
Surface energy balance of urban areas depends on the thermal features of building materials, as well as the overall urban layout and various anthropogenic factors. In extended urban areas, all these factors give rise to the phenomenon known as Urban Heat Island (UHI). From the point of view of urban health, the occurring of UHI drastically changes the fluid dynamic interaction between the air and the city surface, often preventing the dispersion of gaseous pollutants. In the last years in fact, several studies have monitored the increasing trend of breathing diseases and allergies correlated with the presence of UHI. Nowadays, a rational design of the urban areas within large towns should t…
Assessment of indoor illuminance and study on best photosensors' position for design and commissioning of Daylight Linked Control Systems. A new method based on Artificial Neural Networks
Abstract 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 …
A photovoltaic panel coupled with a Phase Changing Material heat storage system in hot climates
Nowadays, there is a great impulse in the field of photovoltaic cell systems (PV) to develop new devices with better energy conversion performances and higher cost effectiveness. This paper is focused on the design and development of a modified PV system, consisting of a normal PV panel coupled with a Phase Change Material (PCM). PCMs are "latent" energy storage materials, using chemical bonds to store and release heat. The system is based on the idea that decreasing the operating temperature of the panel causes an increase in its energy conversion efficiency. A theoretical analysis of the system was accomplished by using COMSOL MULTIPHYSICS, a partial differential equations (PDEs) solver. …
ICT applications for improving the generation and distribution efficiency of a small mediterranean island
The paper presents a study on the opportunities offered by ICT for improving the efficiency of the generation and distribution system of a small island. The island taken into consideration is the Italian Lampedusa island. In the paper, the power distribution system of the island is described and the summer and winter daily load profiles are examined in order to define the more suitable control actions for improving the generation and distribution efficiency of the power system. Finally the architecture of an idoneous control system for the smart grid is proposed and an evaluation of the purchase and installation costs of components and devices for the transition of a traditional house towar…
Forecasting daily urban electric load profiles using artificial neural networks
The paper illustrates a combined approach based on unsupervised and supervised neural networks for the electric energy demand forecasting of a suburban area with a prediction time of 24 h. A preventive classification of the historical load data is performed during the unsupervised stage by means of a Kohonen's self organizing map (SOM). The actual forecast is obtained using a two layered feed forward neural network, trained with the back propagation with momentum learning algorithm. In order to investigate the influence of climate variability on the electricity consumption, the neural network is trained using weather data (temperature, relative humidity, global solar radiation) along with h…
Characterization of a small Mediterranean island end-users’ electricity consumption: The case of Lampedusa
Abstract 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 f…
Concrete thermal energy storage for linear Fresnel collectors: Exploiting the South Mediterranean’s solar potential for agri-food processes
Abstract 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 …
Realization of an Energetic Hub Based on a High-Performance Dish Stirling Plant
In this work the realization of an energetic hub based on a high-performances dish Stirling system, at the DEIM of the University of Palermo, is presented. The realized system is the first top rated solar thermodynamic plant directly connected to the national electric grid. The connection permits the electricity injection into the grid and allows to access to national renewable energy incentives regime. The system realization was possible thanks to an international cooperation between the University of Palermo and the private company Horizon S.r.l., official partner of Ripasso Energy AB, owner of this technology. Initial data of the plant energy production and the foreseen improvements for …
Alcuni indici per la valutazione dei sistemi di controllo per l’illuminazione
Gli edifici smart hanno visto negli ultimi anni una sempre più ampia diffusione. Per questo motivo ricercatori, progettisti e tecnici, hanno posto una crescente attenzione sull’utilizzo di sistemi di controllo automatici per l’illuminazione. Questa tipologia di sistemi gioca, infatti, un ruolo chiave nel raggiungimento di significativi riduzioni dei consumi elettrici e dei benefici legati all’utilizzo della luce naturale (ad esempio il comfort visivo degli occupanti, il benessere e la produttività). È prassi comune, durante la fase progettuale, correlare il risparmio energetico con la disponibilità della luce diurna, poiché risulta un obiettivo rilevante per progettisti e architetti.
The Energy System of Sicilian Region, Italy: 2014 situation and evolutionary trends
The development of reliable energy scenarios are become increasingly more important and crucial due to scientific interest but also because it is essential for the deployment of effective energy policies in the territory. The depletion of Fossil Fuels and the need for the most industrialized countries to achieve the target of a sustainable development have induced important national, European and global initiatives. These actions have led to major changes on each energy system of countries and regions, contributing to the evolution of new local energy systems. In this paper, the Authors have collected, processed and analyzed the data concerning the evolution and changes of the Sicilian ener…
Energy assessment of a dish-Stirling system powering a reverse osmosis plant for seawater desalination
Water scarcity in many regions of the world and the global demographic growth make the desalination of seawater and/or brackish an effective solution to meet the growing demand for freshwater. Nowadays, reverse osmosis has the largest share of the global installed desalination capacity. The impelling need to reduce greenhouse gas emissions has been pushing the search for sustainable technologies to produce the electricity needed to power reverse osmosis plants. Among solar technologies, little attention has been paid to the possibility of powering reverse osmosis with electricity from the dish-Stirling concentrator. To fill this knowledge gap, this paper assesses the energy-saving potential…
Deep learning strategies for automatic fault diagnosis in photovoltaic systems by thermographic images
Abstract Losses of electricity production in photovoltaic systems are mainly caused by the presence of faults that affect the efficiency of the systems. The identification of any overheating in a photovoltaic module, through the thermographic non-destructive test, may be essential to maintain the correct functioning of the photovoltaic system quickly and cost-effectively, without interrupting its normal operation. This work proposes a system for the automatic classification of thermographic images using a convolutional neural network, developed via open-source libraries. To reduce image noise, various pre-processing strategies were evaluated, including normalization and homogenization of pi…
A feasibility study of some DSM enabling solutions in small islands: The case of Lampedusa
Abstract 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 ef…
Effects of the air density value on a wind generator electricity production capability
The paper main issue is the evaluation of the influence of the air density value on the electricity production capability of a wind generator. Two different density air mathematical models, where the density has not a constant value, are here taken into account and compared in terms of reliability, accuracy and computational burden. Evaluations are carried out thanks to a horizontal axis wind generator full model built by the Authors in Matlab/Simulink environment. Simulation results are compared with real data.