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Steady-state energy and exergy evaluation are performed on two designs of a hybrid building integrated photovoltaic thermal (BPT) unit and a thermal wheel (SRX). The working principles of these designs in summer are similar such that the warm outside air is precooled by exchanging heat with air coming out of the building in SRX and then enters the building. Also, other outlet air from SRX passes through the BPT unit and cools PV modules, boosting their efficiency. The working principle of the design A in winter are that the outside air is preheated by receiving heat from the building exhaust air in SRX and then preheated again by passing through the BPT system. The design B works in the same way in winter, with the air passing through the BPT system first and then the SRX. The outcomes revealed that the annual total rate of thermal energy, electrical energy and thermal exergy outputs of the design A are 23183.4 kW h, 5994 kW h, 261.6 kW h, respectively, while these values for the design B are respectively 22785.2 kW h, 6030. 6 kW h and 243 kW h. In addition, it was found that the overall energy/exergy performance of design A is better/worse than design B.

Improvement of solar still desalination performance has become the agenda of researchers in recent years to be able to make the most of the development of such systems in times of crisis and water scarcity. In the current experimental study, using two solar still desalination systems, the effect of cold plasma coat using Dielectric Barrier Discharge (DBD) on the condensation surface is investigated. To achieve this goal, two still solar systems are tested under the same climatic conditions to demonstrate the effects of the cold plasma coating on the condensation surface wettability and hydrophobicity. Additionally, influence of plasma layer on the internal condensing surface temperature and freshwater production rate is examined. Experimental results show that the contact angle between water droplets and glass cover after using plasma coating will increase, which increases the surface hydrophobicity. Results reveal that the amount of produced fresh water in the uncoated surface desalination system equivalent to 485 ml, while in the system with cold plasma, the maximum productivity with the maximum average solar radiation of 1000 W / m 2 and the absorber wall temperature of 70.1 °C, and surface angle of 35° in the experiment day is about 610 m L . Additionally, calculations represent that the produced freshwater using plasma coating increases by 25.7% compared to the uncoated system. The quality of lab-prepared saltwater samples was analyzed before and after desalination, and the results comply with the World Health Organization guidelines for drinking water quality.

Intermittent behavior of renewable energy triggered researchers for using energy storage systems to provide continues operation of renewable-based energy systems. In the current study, an integrated energy system including compressed air energy storage, Rankine cycle, Proton Exchange Membrane (PEM) fuel cell (FC), and thermoelectric generator (TEG) modules are investigated to introduce a new system. To show effects of adding TEG units and PEM fuel cell in the new configuration, three arrangements including conventional compressed air energy storage system (CAES), CAES/TEG and CAES/TEG-FC are investigated. It is found that the proposed CAES/TEG-FC system energy efficiency is 31.85%, which is 1.6% higher than conventional CAES. The exergy efficiency of CAES/TEG-FC is 35.13%, which is 1.44% higher than the conventional one. The proposed system generates 35.6 kW hot water and charge/discharge time are 2.91 hr/4.64 hr. A parametric analysis conducted on the discharge mass flow rate, intercooler outlet temperature, compression pressure ratio, and wind velocity with charging time, exergy efficiency, and total useful products as three major outputs. The tri-objective optimization shows by the technique for order of preference by similarity to ideal solution the optimized value of exergy efficiency, total useful output, and charge time are 34%, 1078.46 kW, and 5.28 hr.