Search results for " Solar"
showing 10 items of 958 documents
Assessment of the mean radiant temperature in urban areas: methods at comparison
2018
Mean radiant temperature may play a pivotal role in the assessment of the outdoor environmental conditions in urban areas. However, its assessment in urban settings is not a simple task owing to the presence of complex and articulated environment and of solar radiation. The article aims to perform a comparison among the results yielded by different methods: the globe-thermometer method, and the six-directional technique. The scope of such a survey is an analysis of the actual appropriateness of the more practical, albeit less accurate, globe-thermometer method to outdoor environments. Furthermore, an analytical model, previously elaborated by the authors and here modified to make it applica…
LCA of a solar heating and cooling system equipped with a small water–ammonia absorption chiller
2012
The development of renewable energy technologies is a critical tool for reducing climate change and the reliance on fossil fuels. However, renewable energy technologies cannot be considered totally clean because they require energy consumption and have environmental impacts that cannot be neglected during their life cycle. In this paper, the life cycle assessment methodology was applied to assess resource use and other environmental burdens related to the entire life-cycle steps of a solar cooling plant. The investigated system works with an absorption chiller assisted by a solar plant. Two back-up configurations (hot back-up and cold back-up) were examined in two localities: Palermo (south…
Valutazione mediante tecnica fotografica dell'oscuramento della radiazione solare dovuto alle ostruzioni
2010
Si propone un nuovo metodo che consente di utilizzare l’immagine fotografica di ostacoli ombreggianti per valutarne l’effetto oscurante nei confronti della radiazione solare diretta incidente su di una superficie. Il metodo proposto è simile a quello che prevede l’impiego del diagramma cilindrico dei percorsi solari, calcolati in funzione dell’azimuth e dell’altezza solare, e la sovrapposizione su di esso del poligono raffigurante l’oggetto ostruente costruito in base alle coordinate cilindriche dei suoi punti più significativi. La nuova procedura prevede invece la sovrapposizione sulla fotografia del percorso solare opportunamente trasformato secondo le regole della prospettiva. E’ così po…
A photographic method to estimate the shading effect of obstructions
2012
Abstract A new, simplified photographic method is proposed to estimate the shading effects of obstructions. In spite of the complex mathematical background of the new tool, its practical application is very simple, and only requires the measurements of three angles for each photograph. The proposed method is particularly useful for overcoming the difficulties caused by the need to accurately describe surrounding objects to estimate shading effects. The new method uses the information contained in a picture and allows one to draw daily solar paths directly on the photograph. The procedure is useful to verify the suitability of a generic site for solar exploitation; its main benefit is the si…
The importance of reliable climatic data in the urban energy policy
2011
In the last years, more and more attention has been focused on energy issues, in particular at urban level, as it is pointed out by the Directive 2002/91/EC on the Energy Performance of Buildings. In fact, the building sector encompasses nearly 30% of the energy whole consumptions. To try to limit such consumptions, both central and local governments should plan effective policies, such as promoting the use of renewable sources and of more energy efficient buildings (e.g. by means of green coverings). But in order to do that, local administrations should provide reliable tools for engineers and technicians to plan such systems. Nowadays, several software are available; the weak point is the…
Organic Rankine Cycle fed by flat-plate solar collectors: a case study
2015
L'attuale tendenza dell’utilizzo di sistemi di risorse energetiche distribuite (sistemi DER), insieme con il crescente sviluppo tecnologico, incoraggia l'uso di tecnologie capaci di recuperare efficacemente energia da fonti di calore a temperatura bassa o moderata, che rappresentano un'opzione essenziale per affrontare le problematiche energetiche ed ambientali. In questo contesto, i cicli Rankine a fluido organico (ORC) si stanno affermando come una tecnologia molto promettente tra quelle attualmente disponibili, in particolare per bassi valori di temperatura. I principi di funzionamento dei sistemi ORC sono essenzialmente gli stessi di quelli del ciclo Rankine. Nei sistemi ORC, l’acqua è …
Introduction of Offshore Wave, Wind and Solar Energies in Vietnam
2020
In Vietnam, the energy demand shows an ever-increasing trend. To limit the utilization of fossil fuels and the following consequences for the environment, renewable energy sources must be adopted. In this context, the paper assesses the utilization of offshore wind and sea wave, by considering a commercial wind turbine and a prototypical wave energy converter. Solar energy can be optionally also collected by this device. An algorithm is introduced to find the best composition of the three sources able to cover a desired share of energy demand. The approach is applied to Ca Mau, a province in the southern part of Vietnam. Finally, the results encourage the adoption of these energy sources th…
Towards achieving net-zero energy communities: Investigation of design strategies and seasonal solar collection and storage net-zero
2019
Abstract This paper explores a solar mixed-use community and its potential towards achieving net-zero energy status. This mixed-use community combines residential and commercial/institutional buildings. Energy performance of this neighbourhood is estimated in terms of energy consumption and generation potential by means of building integrated PV systems. A solar thermal collector system combined with a borehole thermal energy storage (BTES) is designed to investigate the impact on the overall performance of the neighbourhood. The design of solar thermal collectors and the sizing of short-term thermal energy storage is based on the analysis of the thermal loads for heating and domestic hot w…
Beccali M., Progettazione, realizzazione e monitoraggio di un impianto Solar Desiccant and Evaporative Cooling (DEC)
2010
Valutazioni tecniche ed economiche sull'uso degli inseguitori solari
2009
I processi di antropizzazione connessi allo sviluppo del settore energia hanno determinato delle “impronte” sul nostro pianeta ormai indelebili. Non resta che provare a ridurre i consumi energetici e affidare la produzione dell’energia ad un mix equilibrato di fonti. In questo contesto, con particolare riferimento alla produzione dell’energia elettrica, lo sfruttamento della risorsa solare ha assunto un ruolo di primo ordine. Gran parte delle attività di ricerca e sviluppo del settore si è concentrata sulle tecniche e sulle metodologie innovative di conversione della fonte in energia elettrica. Accanto a queste, a parità di tecnologia di conversione adottata, altre attività di ricerca e svi…