Vol 53, No 2 (2017)

The main element which justifies the installation of a photovoltaic system is the solar energy potential. Various structures of artificial neural networks (ANNs) are used for predicting the sun location, the global solar radiation (GSR) at horizontal and inclined plans. Real meteorological data have been exploited in order to validate the computation results. The ANNs are also carried out to predict the current-voltage characteristics of the photovoltaic module. It can be concluded that the ANNs effectively predict the behavior of photovoltaic system parameters with good a coefficient of determination.

In the last two decades or so, Electric Vehicles (EV) start to be part of the transportation sector. EV is supplied with storage batteries, that powered from the electrical power grid. Therefore, EV considered to be a load on the electrical power grid. But on the other hand, EV could be working as a source of energy. So, power can be recovered back to the grid in case of unused. In this paper, we studied the effect of connecting the energy from Vehicle to power grid (V2G) technology at substation 33 kV/11 kV located at Amman city. The load profile for each feeder at the substation is been considered. The substation and the out feeders build and tested using DIGSILENT software. We studied and analyzed the harmonic distortion that the charge controller produces it on the grid for eight scenarios at different hours for winter and summer semesters. In addition, the effect of V2G technology on the stability was found for fourteen scenarios at different penetration level for electric vehicles. Finally, the effect of V2G technology on voltage stability was found for three cases. We compared he results with IEEE standard for the allowable harmonic distortion limits, where the highest total harmonic distortion occurs at summer peak and high penetration for electric vehicles which equal 0.37%, and the frequency stability results compared by the NECA (National Electricity Code Agency).

The composition and photovoltaic characteristics of Au–Zn_xCd_1–xS–Mo–thin film structural injection photo detectors sensitive to narrow the ultraviolet region of the electromagnetic spectrum created and investigated. Studies of the morphology and composition of Zn_xCd_1–xS films showed that in the Au–Zn_x–Cd_1–xS–Mo–UV structure, with a narrow photosensitivity spectrum, x = 0.6 ± 0.02. The features of current transport mechanism in the structure and the basic parameters of semiconductor material are defined. Polycrystalline Zn_xCd_1–xS is a wide-band-semiconductor material may be used instead of the CdS buffer layer in various types of heterostructural solar cells. This will give an opportunity to increase the photo sensitivity of the structure in the short-wave part of the radiation spectrum, increase the built-in potential and solve the problem of open circuit voltage deficiency in the thin-film solar cells.

The modeling and simulation of combined solar and heat pump (SHP) systems is a challenging task as it requires expert knowledge in modeling as well as in the behavior of the real systems. As an example of a SHP system, this work considers parallel solar thermal and heat pump systems with ground or air source heat pumps for the efficient energy supply of buildings. An introduction to SHP systems and the considered system concepts is given and the challenges in designing new models within the simulation environment TRNSYS are described. Finally, a TRNSYS-based stand-alone tool (SHP-SimFrame) ispresented which enables users to analyze predefined SHP concepts with hardly any knowledge in modeling and simulation itself.

Solar energy presents one of the frequent used energy resources to desalinate water especially with reverse osmosis desalination process. Photovoltaic thermal collector (PV/T) is a hybrid generator which converts solar radiation into useful electric and thermal energies simultaneously. This paper gathers all PV/T submodels and reverse osmosis desalination model in order to form a unique dynamic model that reveals PVT based reverse osmosis desalination interactions. As the system is a multi-input/output/output system, a state space model based on energy balance equations is developed in order to analyze and assess the parameters behaviors and correlations of the system constituents. The model simulation is performed using LabVIEW software. The simulation reveals the influence of heating feed water on the process efficiency and the afforded energetic gain by the coolant fluid circulation.

Renewable energies are gaining importance due to the steadily increasing scarcity of fossil fuels, the ongoing climate change and last but not least the risks which accompany the use of nuclear power. In this growing market, solar thermal power plants offer a centralized, potentially load following electricity production. To serve this need, the integration of thermal energy storage systems is essential. The Moving Bed Heat Exchanger MBHX storage concept for CSP systems using sensible heat transfer medium aims at using a low cost solid storage media. This concept requires intermediate bulk cycles to transfer heat between the solar field and the storage material (the bulk). Heat Transfer Fluids (HTF) such as synthetic oils (mobiltherm 603) are typically used. In this work, granular materials such as sand and rocks are studied to present an additional HTF to represent an efficient and cost-effective alternative. Low cost solid particulates can store and transport heat at temperatures over 1000°C. For the purpose of heat recovery, a moving bed heat exchanger (MBHX) is applied and tested. In this study, the dense granular mass is gravity-driven through a heat exchanger. The performance of the MBHX with the utilization of Sand, Basalt, and a Mixture of Sand and Basalt as a granular material was experimentally investigated. It is found that the effectiveness of the MBHX using a mixture of 50% sand and 50% basalt improved by 30% compared to using sand alone.

The Cu(In_0.7Ga_0.3)Se₂ nano solar cell pn junction structure consist of six layers of Al/CIGS/nano-CIGS/CdS/ITO/PET with thicknesses about 200, 500, 70, 100, 150 nm and 170 um were deposited by thermal evaporation technique at vacuum pressure 2 × 10^–5 mbar respectively. where the ITO/PET conductive flexible substrate with sheet resistance 15 Ohms per sq. The X-ray diffraction analysis showed that as-deposited thin films CIGS and CdS are polycrystalline where optical energy gap and carrier concentration are found that 1.15 and 2.38 eV with p = 3.58 × 10¹⁰ cm^–3 and n = 3.11 × 10¹³ cm^–3 respectively. CIGS nano solar cell thin films are deposited on CdS/ITO/PET with assistance of inlet Argon gas vacuum pressure at 1, 5, 20 mbar by thermal evaporation technique at room temperature by using Inert gas condensation (IGC) is the method by which one can deposit films with high purity as deposition is done in low vacuum. The high magnification SEM image of CIGS nano-structures synthesized at 20 mbar revealed that the particles have exact spherical shape with sizes ranged from few nanometers to hundreds nanometers due to agglomeration effect. It was found that the grain size and the root mean square of surface roughness increases as Argon gas pressure increase. Therefore the structure of CIGS thin films has been changed from polycrystalline to nanostructure and have been found with increase Argon gas vacuum pressure from 1mbar to 5 mbar and then 20 mbar will increase grain size at 2θ = 32° from 15.9, 18.9 and 25.7 nm with decrease optical energy gap from 1.54, 1.44 and 1.26 eV respectively. The results showed the efficiency increase from 1.37% of CIGS/CdS to 2.01% of CIGS nano thin films of solar cells.

In this work we have studied numerically the charging and the discharging of solar thermal energy stored (TES) using latent heat from a storage unit contains PCMs. We have also studied the improvement of the heat transfer between fluid which is the water and the PCMs by adding the fins to our storage unit with various configurations, including in-line fins and staggered fins. Then, we studied the assembly of two PCMs in our storage unit. In addition, an experimental work has been validated. The ANSYSFLUENT 15 code was used to solve the formulation of the fusion/solidification processes, where three users define have been developed to describe the thermo-physical properties of the PCMs.

This paper aims to define a control and management strategy for water pumping system which would be powered by a hybrid PV/diesel generator system with battery storage. The particularity of the proposed power management method is to ensure the water volume in need and to maximize the use of PV generator while limiting the use of the diesel generator. In order to capture the maximum power from PV generator, a fuzzy logic maximum power point tracking controller is applied. On the other hand, a PI regulator is used with a boost converter in order to adapt the voltage of the battery bank to the DC bus. The water flow of the pump is also controlled. The developed power management and control strategy has been implemented using SIMPOWER toolbox in Matlab/Simulink. The obtained satisfying simulation results prove the efficiency of the proposed solution that assures continuous supply of water and electricity.