Search

Thermal energy storage (TES) is a technology that stocks thermal energy by heating a storage medium so that the stored energy can be used at a later time for heating applications and power generation. This paper is focused on an experimental study of the thermal behavior of a mini Salinity-Gradient Solar Pond (SGSP) exposed to a solar simulator. Experiments were carried out in an environmental chamber. In fact, a comparison between the integration and the absence of Ultra Violet (UV) filter has been done using two experimental prototype solar ponds built at the Environmental Energy Laboratory at the Marche Polytechnic University in Ancona, Italy. Furthermore, representative results illustrating the influence of simulator spectrum on the distribution of temperature on a SGSP and the effects of the thermal performance has been discussed. In the present study, we have also focused on the assessment of Phase Change Material (PCM) properties. For this purpose, the performance of adding salt hydrates PCMs to a small salinity-gradient solar pond has been studied. The obtained result provides evidence that the solar pond with PCM may be used as a hot water source for domestic applications by collecting and storing solar energy at the same point.

Non-residential buildings like healthcare ones contribute to energy consumption and cause a negative environmental impact. This is mainly due to the age of the buildings, their poor level of energy efficiency and the implementation of only a basic maintenance plan. Owing to the very limited budget available for public administrators, Energy Performance Contracting (EPC), that entails the involvement of an Energy Service Company (ESCo), can provide the entire or part of the capital needed for investments aimed at progressively increasing energy efficiency over their service life. In this paper, three acute hospitals and two community clinics built in Italy are analysed, in order to assess the economic feasibility of several energy renovation actions that can be included within EPC contracts. To this purpose, the outcomes of energy audits carried out in 2014 about these buildings are reported, which involved analyses of consumption measured over the previous three years and assessment of use profiles for the development of models to break down the overall consumption and to estimate potential savings. Diverse improvement strategies were assessed, consisting in either isolated or combined renovation actions and tested on the five buildings, whose comparison was carried out in terms of energy saving, pollution reduction and economic feasibility. As a result, the best combined renovation actions per each hospital were recommended, that included – but were not limited to – the improvement of the control and regulation of existing sub-systems without replacement, partial replacement of other sub-systems and integration of renewables. Finally, each scenario was evaluated through the payback period and other economic performance indexes in order to assess the feasibility of the EPC framework when applied to this case study.