Abstract:Hydrogen produced by renewable sources represents an interesting way to reduce the energetic dependence on fossil fuels in the transportation sector. This paper shows a feasibility study for the production, storage and distribution of hydrogen in the western Sicilian context, using three different renewable sources: wind, biomass and sea wave. The objective of this study is the evaluation of the hydrogen demand, needed to replace all diesel supplied buses with electrical buses equipped with fuel cells. An economic analysis is presented with the evaluation of the avoidable greenhouse gas emissions. Four different scenarios correlate the hydrogen demand for urban transport to the renewable energy resources present in the territories and to the modern technologies available for the production of hydrogen. The study focuses on the possibility of tapping into the potential of renewable energies (wind, biomass and sea wave) for the production of hydrogen by electrolysis. The use of hydrogen would reduce significantly the emissions of particulate and greenhouse gases in the urban districts under analysis.

SUMMARYWorth aged buildings represent among the existing buildings a special case when it comes to their energy refurbishment. Current available technologies for building components, characterized by high level of thermal performances, unfortunately, are also characterized, not rarely, by limited compatibility with the architectural integrity of the building. In other words, the so-called Best Available Technologies that are effectively adopted to optimize the energy performances of buildings, in the case of aged buildings to which a certain artistic, historic and/or architectural merit is recognized (heritage houses) could, actually, determine such kind of conflicts and therefore leading to the selection of "noninvasive" but less performing building and plant elements.To check the effectiveness of these less performing technologies, we investigated the energy performance of two different refurbishment configurations of the building envelope of a heritage house: a "best available technology" scenario, in which interventions assumed consist of using the best available technology for energy saving; and an "allowed best technology" scenario, in which interventions assumed consist of using technologies that, although not the best available, are anyway "allowable" according to the cultural heritage preservation requisites and rules. A cost-based comparison between these configurations of the building envelope was also carried out.Results of this comparative analysis are reported in this paper. RIASSUNTOGli edifici di pregio rappresentano, tra quelli esistenti, un caso speciale quando ci si confronta con la riqualificazione energetica. Le tecnologie attualmente disponibili per i componenti edilizi, caratterizzate da un'elevata prestazione termica, sfortunatamente sono anche, non raramente, affette da una limitata compatibilità con l'integrità architettonica dell'edificio. In altre parole, le cosiddette migliori tecnologie disponibili (BAT) che sono efficacemente adottate per ottimizzare le prestazioni energetiche degli edifici, nel caso degli edifici storici, ai quali è riconosciuto un certo valore artistico, storico e/o architettonico (edifici di pregio o del patrimonio culturale), potrebbero in realtà tale tipo di conflitti e quindi condurre alla scelta di elementi di involucro e di impianto "non invasivi" ma meno performanti. Per controllare 'efficacia di queste meno performanti tecnologie, abbiamo investigato la prestazione energetica di due diverse configurazioni di riqualificazione energetica dell'involucro edilizio di un edificio storico: uno scenario "migliore tecnologia disponibile", in cui gli interventi ipotizzati consistono nell'impiego della migliore tecnologia disponibile per il risparmio energetico; e uno scenario "migliore tecnologia adottabile" , in cui gli interventi ipotizzati consistono nell'impiego di soluzioni tecnologiche che, sebbene non le migliori disponibili, sono comunque certamente adottabili secondo gli standard ed i regolamenti per la conservazione del patrimonio culturale degli edifici....

Abstract:The main purpose of this paper is to analyze the energy production in the Maltese islands, focusing on the employment of renewable energies in order to increase their energy independence. The main renewable source here proposed is wave energy: thanks to a strategic position, Malta will be able to produce electrical energy using an innovative type of Wave Energy Converter (WEC) based on the prototype of a linear generator realized by University of Palermo. The use of this new technology will be able to cut down the electrical energy production from traditional power plants and, consequently, the greenhouse gas emissions (GHG). Wave energy source and off-shore photovoltaic (PV) technology are here proposed. Particularly, the installation of 12 wave farms, for a total installed capacity of 86 MW, will generate about 9.5% of Malta's energy requirement in 2025, while the installation of 9.6 MW of off-shore PV will generate about 0.73%.

Abstract. The thermal insulation of buildings, intended as wrap feature which determines the dispersion of heat, the reference parameter is necessary to contain the thermal losses during the winter season. The transmittance of the opaque components, used as an indicator of the energy quality of a casing, together with the overall coefficient of dispersion, represents a proper descriptor of the behavior during the heating season.However, if a strong insulation in winter conditions brings only positive effects, the same cannot be said for the summer conditions. A high value of the insulation in the casing is convenient only when the gains free, either in the form of solar contribution that of endogenous heat, are controlled and restricted. From the national transposition of the 2002/91/CE legislation up to the 2010/31/EU on the energy performance of buildings, performance values are set very restrictive transmittance of opaque surfaces that both of those transparent to the new buildings. The same does not happen for the thermophysical characteristics able to implement strategies for the control of solar radiation during the summer period, the fluctuations in external temperatures during the summer period.This article shows some experimental evidence of the effects on transmission rate and density of the opaque elements of the buildings carried out on a case study of a representative building of climate-Mediterranean summer: The study verify the results produced by increased insulation of the building envelope on energy performance of buildings during the summer through indicators such as temperature and energy consumption to maintain the same constant with respect to the prescribed values.

Among renewable energy resources, wind energy became more attractive in the last decade. Wind farm installations dramatically increased in areas where climatic conditions, topography, and environment have allowed their development. The installation of wind turbines, usually carried out in remote areas, recently began to cover areas identified by a complex terrain such as urban and suburban zones. Although these new plant choices are characterized by lower productivity, there is increasing interest in wind energy production in both urban and suburban areas. In this work the authors have carried out an energy analysis developed from a sample of small wind turbines available on the market. This study shows how variable the energy production of a small wind turbine can be according to many design and context parameters: wind profiles, installation height, land use, and characteristics of the turbine.