Antonio Gagliano

Assessment of micro-wind turbines performance in the urban environments: an aided methodology through geographical information systems

Among renewable energy sources, the electrical generation from micro-wind turbines has not yet disclosed its huge potential especially in urban settings. Increasing the spread of micro-wind turbines not only promotes the decentralized generation of energy, but also helps tackle fuel poverty and to achieve reductions in the emission of greenhouse gases (GHGs).This work proposes an innovative methodology to exploit wind flow fields, calculated by means of computational fluid dynamic (CFD) codes in urban environments, within the geographical information system (GIS) platform. In this way, the platform of users is amplified, even non-specialist users, that can utilize wind data to evaluate the potential production of electricity using micro-wind turbines. A pilot study was conducted for assessing the applicability of the approach in a Sicilian city. The results of this case study show the energy yield produced from a building-mounted wind turbine (BUWT). The developed methodology permits to enrich the information usually stored in the GIS platform allowing to supply useful information about suitable sites where micro-wind energy plants can be installed and to assess the production of renewable energy in the urban settings.

Study on the Application of Cool Paintings for the Passive Cooling of Existing Buildings in Mediterranean Climates

Building roofs play a very important role in the energy balance of buildings, especially in summer, when they are hit by a rather high solar irradiance. Depending on the type of finishing layer, roofs can absorb a great amount of heat and reach quite high temperatures on their outermost surface, which determines significant room overheating. However, the use of highly reflectivecool materials can help to maintain low outer surface temperatures; this practice may improve indoor thermal comfort and reduce the cooling energy need during the hot season. This technology is currently well known and widely used in the USA, whilereceiving increasing attention in Europe. In order to investigate the effectiveness of cool roofs as a passive strategy for passive cooling in moderately hot climates, this paper presents the numerical results of a case study based on the dynamic thermal analysis of an existing office building in Catania (southern Italy, Mediterranean area). The results show how the application of a cool paint on the roof can enhance the thermal comfort of the occupants by reducing the operative temperatures of the rooms and to reduce the overall energy needs of the building for space heating and cooling.

Synergic effects of thermal mass and natural ventilation on the thermal behaviour of traditional massive buildings

The energy policies about energy efficiency in buildings currently focus on new buildings and on existing buildings in case of energy retrofit. However, historic and heritage buildings, that are the trademark of numerous European cities, should also deserve attention; nevertheless, their energy efficiency is nowadays not deeply investigated. In this context, this study evaluates the thermal performance of a traditional massive building situated in a Mediterranean city. Dynamic numerical simulations were carried out on a yearly basis through the software DesignBuilder, both in free-running conditions and in the presence of an air-conditioning (AC) system. The results highlight that the massive envelope of traditional residential buildings helps in maintaining small fluctuations of the indoor temperature, thus limiting the need for AC in the mid-season and in summer. This feature is highly emphasised by exploiting natural ventilation at night, which allows reducing the building energy demand for cooling by about 30%.The research also indicates that, for Mediterranean climate, the increase in thermal insulation does not always induce positive effects on the thermal performance in summer, and that it might even produce an increase in the heat loads due to the transmission through the envelope.

GIS-Based Decision Support for Solar Photovoltaic Planning in Urban Environment

In 2007, the European Council decided a fixing goal of 20% contribution of the renewable energy sources (RES) to the total European electric energy production in 2020. Micro-generation systems integrated in urban environment are an interesting opportunity, in terms of research and development of RES. The development of a solar energy planning system to predict the potential of solar energy photovoltaic, solar water heating and passive solar gain is necessary for the optimization of energy efficiency strategies and integration of renewable energy systems in urban areas. The work discussed here relates to solar photovoltaic (PV), technology which has matured to become a technically viable large-scale source of renewable energy sources. This paper illustrates the capabilities of Geographic Information Systems (GIS) to determine the available rooftop area for PV deployment for an urban area and how the methodology may enable planners to consider the urban-scale application of solar energy with greatly increased confidence.

Original articles: Intelligent sun-tracking system based on multiple photodiode sensors for maximisation of photovoltaic energy production

To maximise the energy collected by a given photovoltaic system (PVS), it is important to track the position of the sun so that the PV panels are exposed to the maximum global radiation at any given time. Thus, it is useful to determine the direction of the maximum global radiation, which does not correspond with the condition of orthogonality between the plane of the array and the beam component of the solar radiation. Thus, it is worthwhile to investigate a low-cost solar radiation sensing system that can determine this direction. The proposed system consists of a structure of nine photodiodes (FDs); a suitable analysis of the output signals calculates the azimuth and solar height angles, which are related to the direction of maximum solar irradiance. This paper reports the development of hardware (HW) and software (SW) for a prototype system, which is called SoliSector. Outdoor experimental results regarding testing and calibration of the proposed system are also reported.

A proposed methodology for estimating the performance of small wind turbines in urban areas

Large and medium scale wind turbine systems represent feasible renewable resources of energy, that constitute an alternative to conventional energy supply systems. However the development of small-scale wind turbines is still uncertain due to the difficulty in their use especially in urban areas.

The adoption of green roofs for the retrofitting of existing buildings in the Mediterranean climate

AbstractIn recent years, the demand for air conditioning systems has increased considerably. Consequentially, the energy demand for building cooling has become a serious concern. In particular, the energy peak demand that is intensified by the urban heat island (UHI) effect is often a critical issue for the outdated electricity infrastructure in many countries. In order to rationalize the building energy consumption while ensuring indoor thermal comfort, this paper explores the possibilities offered by the retrofitting of existing uninsulated roofs in combination with night natural cooling strategies. To this end, a case study was selected in order to investigate the performance of an extensive green roof (GR) with and without natural ventilation (NV). The selected building is located in Catania, southern Italy, in a very mild climate. Free-running conditions were evaluated together with air conditioning conditions during the daytime and free cooling via natural ventilation at night. The hourly variation ...

Design solutions for reducing the energy needs of residential buildings

Nowadays the concept of Net ZEB is well-known and widespread in the scientific community. The European Union has set ambitious targets for 2020 and even more ambitious for 2050. In order to reduce the domestic GHG emissions by 80-95%, compared to 1990 levels-till 2050, the building sector has to do its part and to pass through a deep restructure. Therefore, it is grown the interest in design and technical solutions for achieving a zero or nearly zero energy building. This paper investigate several construction technologies and system of energy production that can be adopted to build an “enhanced saving” (parsimonious) building, which can strive for the objective of NetZEB. Moreover the economic analysis of the feasibility of the NZEB target has been developed.

Acoustic Quality of a Tensile Membrane Structure used as a Lecture Hall, and Proposals for its Improvement

Tensile membrane structures can offer considerable weight saving, becoming attractive for designers in several technological areas. They also have the advantage of realizing an enormous space without columns and beams. Furthermore, they can produce a unique atmosphere as well as savings on electricity for interior lighting, due to their light transmission properties. Unfortunately, membrane structures have serious defects in sound-insulation performance, rain-noise problems and low thermal insulation. Consequently, it is not easy to ensure acoustic comfort inside tensile membrane structures, because the techniques that normally apply to traditional buildings are not suitable in lightweight structures. For these reasons, this paper investigates the acoustic behaviour of a tensile membrane structure used as a lecture room, through instrumental techniques and simulation with software for room acoustics, in order to propose possible solutions applicable to similar structures.

Thermal Comfort In Operating Rooms:A Case Study

This paper focuses on thermal comfort in hospital operating rooms (ORs). Thermal comfort depends on several factors such as temperature conditions of the operating room, insulation of protective clothing, stress, rate of metabolism and safety mechanisms in the body to keep core temperature stable. The modification of any of these elements triggers defense mechanisms which in extreme cases may lead to serious disturbances in the body. The maintenance of recommended standards (ISO 7330) concerning thermal conditions in operating rooms ensures the highest possible physical capabilities of the personnel while providing maximum safety for the patients. The purpose of the present work is to report the results obtained during an experimental campaign carried out at the Umberto I Hospital in Enna in order to improve efficiency of HVAC installations to secure thermal comfort in the operating rooms.