This paper investigates the uses of solar energy systems in various applications to define the most appropriate system that has highly efficient and reliable. Most of the urban even rural areas that suffer from lack of continuous power supplies it prefer to depend on hybrid systems like solar/wind systems, solar/geothermal system and solar/diesel-battery systems. Investigation indicates that hybrid systems could meet the required loads in different proportions depending on the operating conditions and components of the hybrid system compare with the separate system but has complexity regarding their components of the system with the high initial cost Moreover, Utilize hybrid solar/thermal system is more sufficient than had systems that mentioned as a result of the improvements at his parts to increase the overall efficiency by use PCM, nanofluid or a mix of PCM - nanofluid as cooling the PV panel to keep the efficiency of the solar cells and increase thermal energy. Thus, hybrid solar/thermal systems had proven effective to meet the required loads of electric energy and good capacity to provide thermal energy simultaneously without toxic emissions with a negligible complexity of its components.

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This article describes a novel approach to generate increased turbulence levels in an incoming flow. It relies on a cost-effective and robust semi-active jet grid, equipped with flexible tubes as moving elements attached onto tube connections placed at the intersections of a fixed, regular grid. For the present study, these flexible tubes are oriented in counter-flow direction in a wind tunnel. Tube motion is governed by multiple interactions between the main flow and the jets exiting the tubes, resulting in chaotic velocity fluctuations and high turbulence intensities in the test section. After describing the structure of the turbulence generator, the turbulent properties of the airflow downstream of the grid in both passive and active modes are measured by hot-wire anemometry and compared with one another. When activating the turbulence generator, turbulence intensity, turbulent kinetic energy, and the Taylor Reynolds number are noticeably increased in comparison with the passive mode (corresponding to simple grid turbulence). Furthermore, the inertial subrange of the turbulent energy spectrum becomes wider and closely follows Kolmogorov's -5/3 law. These results show that the semi-active grid, in contrast to passive systems, is capable of producing high turbulence levels, even at low incoming flow velocity. Compared to alternatives based on actuators driven by servo-motors, the production and operation costs of the semi-active grid are very moderate and its robustness is much higher.

Vehicle engine cooling systems have several functions. Excess heat removal from the engine helps to rapidly cool it, quickly reach operating temperature, maintain a constant engine operating temperature, and provide heat to the vehicle’s passenger compartment. Developments in the automotive industry, such as hybrid and electric vehicles, now also involve the temperature management of battery packs. Currently, the coolant used in cooling systems is water or an equivalent substance. Water as a coolant has low thermal conductivity. Therefore, researchers are trying to use nano-liquid as a coolant in the cooling system. Better results are expected by use of this alternative. Nano-liquids contain metal particles that enhance thermal transfer properties, so current and future cooling systems could operate more efficiently. Adding phase change materials to the cooling and air handling systems will result in better efficiency in future vehicles. In the case of hybrid and electric vehicles, the addition of thermoelectric generators to cooling and exhaust systems increase efficiency. Present developments help increase a vehicles’ usability and the possibility of achieving greater efficiency.

The photovoltaic module (PV) consists of many photovoltaic cells made of silicon that lose their properties with an increased temperature. Increasing photovoltaic cell temperature represents an intrinsic problem that causes a drop in the open-circuit voltage of the PV module, thus affecting its performance. The present work investigates using evaporating cooling as a passive cooling technique to absorb the generated heat from the PV module and lower its temperature by cotton wicks immersed in the water (CWIWs) attached to the backside photovoltaic module. The CWIWs decrease air dry temperature and increase humidity and then produce cool air to help cool PV modules. The results showed dropped PV module temperature by about 22% attributed to providing appropriate cooling produced by the moist condition of the cotton bristles immersed by water exposed to the wind. The output power generation and efficiency have increment by 16.3 W and 53%, respectively. The electrical exergy was equivalent to output power under the evaporating cooling, while entropy generation dropped about 14% with increased the PV module temperature.