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Hot water heat stores with stratification are a common technology used in solar energy systems and reuse of waste heat. Adding a PCM module at the top of the water tank would give the system higher storage density, and compensate heat loss in the top layer. The work presented here includes experimental results and numerical simulation of the system using an explicit finite-difference method. Experiments and simulations were carried out using different cylindrical PCM modules. With only 1/16 of the volume of the store being PCM, 3/16 of water at the top of the store was held warm for 50% to 200% longer and the average energy density was increased by 20% to 45%. Furthermore, these 3/16 of water were reheated by the heat from the module after being cooled down in only 20 min.

The transition to a low carbon future is starting to affect landscapes around the world. In order for this landscape transformation to be sustainable, renewable energy technologies should not cause critical trade-offs between the provision of energy and that of other ecosystem services such as food production. This literature review advances the body of knowledge on sustainable energy transition with special focus on ecosystem services-based approaches and methods. Two key issues emerge from this review: only one sixth of the published applications on the relation between renewable energy and landscape make use of the ecosystem service framework. Secondly, the applications that do address ecosystem services for landscape planning and design lack efficient methods and spatial reference systems that accommodate both cultural and regulating ecosystem services. Future research efforts should be directed to further advancing the spatial reference systems, the use of participatory mapping and landscape visualizations tools for cultural ecosystem services and the elaboration of landscape design principles.

Abstract In recent years, the overall energy consumption is increasing significantly and the energy consumption in the building sector represents over 30% of the global ones in developed countries. Thermal energy storage (TES) using phase change materials (PCM), which are materials able to store high amounts of energy as latent heat, is suggested as a possible solution to decrease the energy consumption. The authors of this paper developed materials able to encapsulate/stabilize PCM in addition to isolate an industrial residue from the steel recycling process: electrical arc furnace dust (EAFD). This waste is a hazardous dust, and when it is combined with a polymeric matrix produce dense sheet materials suitable for multilayered constructive systems. In this paper the physical, mechanical, thermal and acoustical characterization of two new materials with EAFD and PCM in a polymeric matrix for constructive system is presented. The results are compared with those obtained for one commercial dense sheet material available in the market, Texsound commercialized by TEXSA (Spain). The new dense sheet materials developed in this paper have similar acoustic properties compared to the results obtained for the commercial material and are competitive with it, even better because the new material incorporates PCM which increases the thermal inertia of final constructive system.

The incorporation of recycled materials in concrete as a partial replacement of cement is becoming an alternative strategy for decreasing energy-intensive and CO2 emissions imputable to the cement manufacture, while investigating new potential uses of such multifunctional materials for environmental sustainability opportunities. Therefore, low-cost and worldwide availability of by-products materials is being assessed for sensible heat thermal energy storage applications based on cementitious materials. A greater concern is especially required focusing on the thermal stability of cement paste under high temperature cycled conditions. Moreover, compatibility between cement type and supplementary cementitious materials is determinant for the proper performance reliability. In this study, benchmark cement types were selected, i.e., ordinary Portland and calcium aluminate. Six supplementary cementitious materials were added to both types of cement in a content of 10 % and 25 %. Thermo-mechanical properties were studied before and after 10 thermal cycles from 290 to 650 ◦C. Results after thermal cycling showed that calcium aluminate cement paste mixtures maintained their integrity. However, most ordinary Portland cement paste mixtures were deteriorated: only mixtures with 25 % cement replacement with chamotte, flay ash, and ground granulated blast furnace slag remained without cracks. Calcium aluminate cement paste mixtures obtained the highest compressive strength, for partial replacement of cement with 10 % of chamotte, ground granulated blast furnace slag, and iron silicate. The incorporation of supplementary cementitious materials did not increase the thermal conductivity. This work was partially funded by the Ministerio de Ciencia, Innovación y Universidades de España (RTI2018-093849-B-C31 - MCIU/AEI/FEDER, UE) and by the Ministerio de Ciencia, Innovación y Universidades - Agencia Estatal de Investigación (AEI) (RED2018-102431-T). The authors at University of Lleida would like to thank the Catalan Government for the quality accreditation given to their research group (2017 SGR 1537). GREiA is certified agent TECNIO in the category of technology developers from the Government of Catalonia. This work is partially supported by ICREA under the ICREA Academia programme and by the Italian project ‘SOS-CITTA’ supported by Fondazione Cassa di Risparmio di Perugia under grant agreement No 2018.0499.026. Laura Boquera acknowledgments are due to the PhD school in Energy and Sustainable Development from University of Perugia. Laura Boquera would like to acknowledge the financial support provided by UNIPG – CIRIAF InpathTES project. The authors also thank the companies that provided the material to make possible this experimental research: Arciresa, Abrasivos Mendiola EDERSA—Masaveu Industria, General Admixtures S.p.A, Mapei, Ciments Molins industrial, and Promsa for the material supplied in this research. Financial support of the UNIPG-CIRIAF team has been achieved from the Italian Ministry of University and Research (MUR) in the framework of the Project FISR 2019: “Eco Earth” (code 00245) and it is gratefully acknowledged.

Abstract Thermal energy storage systems for both heat and cold are necessary for many industrial processes. High energy density and high power capacity are desirable properties of the storage. The use of latent heat increases the energy density of the storage tank with high temperature control close to the melting point. Tube in PCM tank is a very promising system that provides high packing factor. This work presents an experimental study of a PCM tank for cold storage applications. Two different configurations and different flow rates of the heat transfer fluid were studied. The effectiveness of the PCM storage system was defined as that of a heat exchanger. The results showed that the heat exchange effectiveness of the system did not vary with time, decreased with increasing flow rate and increased with increasing heat transfer area. The effectiveness was experimentally determined to only be a function of the ratio m ˙ /A. This equation was found to be adequately be used to design a PCM storage system, and a case study is presented. It was shown that the tube in tank design together with a low temperature PCM is suitable as a thermal storage facility for cold storage.

Supervisory Control and Data Acquisition (SCADA) systems monitor and control electric power distribution. Recent history has shown that cyber-attacks pose a tremendous risk for the economy and safety of modern countries. This paper introduces an architecture and a prototype implementation for a process-aware, network-based Intrusion Detection System (IDS) to secure control networks in the domain of power distribution. Based on a recently proposed process model, the system continuously assesses the local physical process and all control commands with regard to consistency and safety of the underlying physical process. Its detection capabilities focus on process-based attacks like manipulated control commands, which appear legitimate to traditional IDS but might nevertheless have devastating effects on the power distribution. The architecture separates the evaluation part from the traffic processing, which ensures extensibility and scalability. The developed implementation has been successfully deployed at a Dutch power distribution substation. Its detection performance is characterized by a very low miss rate and high precision.

In the present paper design, realization and testing of a novel small scale adsorption refrigerator prototype based on activated carbon/ethanol working pair is described. Firstly, experimental activity has been carried out for identification of the best performing activated carbon available on the market, through the evaluation of the achievable thermodynamic performance both under air conditioning and refrigeration conditions. Once identified the best performing activated carbon, the design of the adsorber was developed by experimental dynamic performance analysis, carried out by means of the Gravimetric-Large Temperature Jump (G-LTJ) apparatus available at CNR ITAE lab. Finally, the whole 0.5 kW refrigerator prototype was designed and built. First experimental results both under reference air conditioning and refrigeration cycles have been reported, to check the achievable performance. High Specific Cooling Powers (SCPs), 95 W/kg and 50 W/kg, for air conditioning and refrigeration respectively, were obtained, while the COP ranged between 0.09 and 0.11, thus showing an improvement of the current state of the art.

Using recycled rubber crumbs as drainage layer in extensive green roofs have high potential to reduce the heating and cooling loads in buildings over traditional materials used as drainage layer, such as pozzolana gravel. However, the environmental impact due to the life cycle should be analyzed to assess its environmental benefit. This paper evaluates the environmental performance of green roofs in which the drainage layer is made of rubber crumbs, a recycled material the use of which is still experimental for this purpose. In this paper Life Cycle Assessment (LCA) is applied to compare the environmental impact of four constructive systems, two extensive green roofs without insulation layer and with different drainage materials, e a recycled material, rubber crumbs, and a conventional one, pozzolana gravel -, in front of two conventional flat roofs, with and without thermal insulation (polyurethane), built in an experimental set-up consisting of four monitored house-like cubicles, located in Mediterranean continental climate (Lleida, Spain). The LCA considered the production, construction, operational, and disposal phases of the roofs, according to UNE-EN 15643-2. The operational phase was carried out using data measured in the experimental set-up, considering heating and cooling energy consumptions in the winter and summer period, respectively.

Abstract An exergy analysis, which only considers the unavoidable exergy destruction, is conducted for single, double, triple and half effect Water–Lithium bromide absorption cycles. Thus, the obtained performances represent the maximum achievable performance under the given operation conditions. The coefficient of performance (COP), the exergetic efficiencies and the exergy destruction rates are determined and the effect of the heat source temperature is evaluated. As expected, the COP increases significantly from double lift to triple effect cycles. The exergetic efficiency varies less among the different configurations. In all cycles the effect of the heat source temperature on the exergy destruction rates is similar for the same type of components, while the quantitative contributions depend on cycle type and flow configuration. Largest exergy destruction occurs in the absorbers and generators, especially at higher heat source temperatures.