An existing PV system is cooled by heat dissipation to air by straight fins arrays attached at the backside of the panels. However, a little average temperature drop has been achieved in the plant. The current research aims to simulate and investigate the low cooling performance experienced in the plant and recommend improved PV cooling by backside installed fins. A CAD model was constructed with CATIA software and imported to ANSYS-Fluent to simulate and investigate the cause of low cooling performance. In addition, cooling performance by 45°, 90°and 135° have been studied. The solar PV panel has 1000-mm-width and 2000-mm-length, whereas the fins' base dimensions are 830-mm-width, and 1260-mm-length and each fin has 80-mm-height. The reference case study's average temperature measured in the actual site is 46.9℃, while the simulation prediction is 48.4℃. The 3.3% difference suggests that the simulation procedure is sufficient to investigate the other cases. Solar PV is paired with the fins air cooling system, stimulating the PV/T with only a 2.7% difference between the actual measurements and the simulation prediction. The bare panel simulation results predicted the backside temperature to be 13.4℃ above the ambient temperature. The 45° and 90° oriented fins reduced the backside temperature to 4.2℃ and 9.54℃ above the ambient temperature. In contrast, the 135° oriented fins have a negative cooling effect, as they increased the backside temperature to 19.05℃ above the ambient temperature. The analysis suggests that the low-performing cooling in the physical system is due to the bad thermal contact between the array base plate and the panel's backside.

In the present work, exergy analysis has been experimentally evaluated for a chest freezer to assist in sizing calculations and selecting the most suitable working fluid, which can reduce the power consumption. In the present work, exergy analysis has been experimentally evaluated for a chest freezer to assist in sizing calculations and selecting the most suitable working fluid to reduce power consumption. The experimental measurements were carried out using a 150 litters chest freezer volume capacity running on R-134a and R-600a using different compressors. The freezer provides measurement instruments for pressure, temperature, refrigerant mass flow and power consumption. The tests were carried out with a standard ambient temperature of 32. The results show that the evaporator had the highest exergy loss value of 59% for R-134a and 62% for R-600a. Compressor exergy losses are 64% for R-134a and 63% for R-600a. The condenser showed exercise losses of 79% for R-134a and 75% for R-600a, while the limitation device (capillary tube) had exercise losses of 87% for R134a and 99.5% for R-600a. The thermal performance of the chest freezer represented by the second low efficiency is 43% for R-134a and 50% for R-600a. The thermal performance of the freezer with R-600a is better than R-134a due to the energy consumption reducing and evaporator behaviour.

Flat Plate Solar Collectors (FPSC) are one of the most environmentally friendly and energy-efficient heating solutions. In this work, the thermal performance of the FPSC for a greenhouse heating system was experimentally and numerically investigated by utilizing distilled water as a working fluid and Al₂O₃-water nanofluid with two different nanoparticle concentrations of 0.2wt.% and 0.5wt.%. The simulation model was conducted using TRNSYS 18, and its outcome was validated with experimental results. As a first step, the study estimates the maximum required amount of energy for a greenhouse in the Scientific Research Center at Erbil, Iraq. A temperature of 23℃ was selected as a set point temperature in the greenhouse, which is essential for the experiments needed for developing several plants. The most interesting finding was that when nanofluids were used as a working fluid, the efficiency gain was larger than with water only. The highest collector efficiency was attained when 0.5wt.% nanofluid was used in the FPSC, which increased the collector efficiency by 17.5% over the water case. Additionally, FR (UL) values for Al₂O₃-nanofluid and water are approximately close to each other, while for all applied concentrations, Al₂O₃-nanofluid's FR (τα) values were more significant than water. Further analysis showed that, during the coldest months of the year, the system could raise the inner air temperature of the greenhouse, which is ideal for farming applications.

The intermittent nature of solar energy is a problem for power demand-supply. In particular, power generation by a solar chimney is insufficient due to low efficiency and interrupted power production. In the current research, an experimental model of an inclined solar chimney is integrated with an external heat source to develop a hybrid solar chimney. The developed hybrid solar chimney utilizes the exhaust flue gas from a lab-scale experimental gas turbine. The exhaust gases from the gas turbine were supplied through a passage underneath the absorber plate of the solar chimney. The absorber plate is modified into a heat exchanger by adding extended surfaces in the flue passage. Furthermore, the hybrid system is experimented outdoors to utilize solar irradiation, and a burner produces the hot gases. Experimental measurements have been carried out in three different cases. The investigated system performance to produce power is enhanced by 91.0% by integrating the inclined solar chimney with an external heat source at an average temperature of only 88.0℃. The results show that the mean enhancement in the air temperature rise of the hybrid mode is 33% compared to the solar mode; this considerably improves the solar chimney performance. The proved concept of the hybrid inclined solar chimney could be adopted in existing thermal power plants to recover the heat losses in the flue gases.

Due to high solar irradiation and the high ambient temperature in Iraq, the solar cell temperature rises, and the electrical power output drops accordingly. In this study, an experimental photovoltaic (PV) panel prototype was developed to study the PV module's performance and power production efficiency. The developed photovoltaic module uses a water-cooling chamber for cooling. This experimental study uses a water-cooling system chamber technique at the rear side of the PV panel. The cooling system solar panel is a closed cycle, and the cooling water contacts the panel directly through the rear side of the PV panel using different flow rates. The results showed that the electrical efficiency increased by 10.42%, 11.87%, 13.77%, 18.1%, and 19.72% when mass flow rates of 1.5, 2, 2.5, 3, and 3.5 l/min, respectively, were used. The thermal efficiency at 1.5 and 3.5 l/min is 49.7% and 79.2%, respectively.

Solar energy systems present a potential solution to global challenges in energy production and addressing environmental issues. However, such systems' performance could deteriorate in harsh weather conditions, which may lead to short- and long-term degradation. Particular attention should be paid to dust accumulation affecting both types of solar systems: Photovoltaic (PV) and Concentrated Solar Power systems (CSP). This review discusses the influencing factors affecting dust accumulation and the dust impact on solar systems. The comparison of dust accumulation effect on both technologies is then assessed. The reported dust accumulation studies showed more performance deterioration in CSP systems than in PV systems. In both cases, dust accumulation leads to a drop in optical characteristics resulting in a loss of energy yield. Potential mitigation methods and their advantages and disadvantages are also reviewed. It is concluded and recommended from the review analysis that dust accumulated on solar systems should be considered in the design and operation phases to define appropriate cleaning methods and frequencies.

Controlled Environment Agriculture (CEA) plays a crucial role in promoting sustainable farming practices within the challenging climate of the Arabian Peninsula. Traditional CEAs, however, are confronted with excessive water and electricity consumption due to the region's elevated temperatures and humidity levels. To address these challenges, an innovative project was carried out at the Al Dhaid Research Station, United Arab Emirates, integrating solar-powered cooling and irrigation, closed hydroponic systems, net-house structures, root zone cooling, and ultra-low-energy drippers. The study employed a cooled greenhouse alongside two net houses, one of which was equipped with a solar-powered cooling and irrigation system. Cucumber crops were cultivated within each structure, demonstrating that the combined technologies could prolong production periods despite increasing temperatures, while simultaneously reducing energy consumption by 95% and water usage by 80%, without compromising crop yield. The findings of this study suggest that the implementation of this novel approach holds significant potential for boosting crop productivity and water efficiency in desert agriculture systems.

Spatial planning and energy planning are two crucial topics related to each other, as both subjects have environmental, social, and economic benefits. Worldwide, few researchers have studied the integration of spatial planning with energy planning, however, in Jordan, this subject remained unexplored. This study aims to assess the sustainable planning practices that are implemented in small-scale projects, it explores the spatial issues that planners should consider to increase the integration of energy technologies into the planning process. A mixed methods approach is employed in data collection and analyses to enhance the accuracy and creditability of the findings. The spatial dimensions of energy planning which include analyzing the project’s master plan, evaluating the urban structure, and calculating energy production are used to assess the existing situation of Zarqa University in Jordan. Numerical and data analyses, site analyses, and field observations are conducted to achieve the research aim. Zarqa University was selected because it is the first Jordanian university that implements energy planning strategies when designing its campus. The study findings confirm the importance of integrating these two disciplines which contribute to achieving effective planning policies, it recommends replicating those strategies in other small projects to enhance their level of sustainability.

The sustainable management of agricultural wastes (AWs) and their valorization for biogas production offer promising alternatives to fossil fuels and contribute to environmentally responsible waste management strategies. This study examines the anaerobic co-digestion (Co-AD) of various AWs, including apples, bananas, carrots, butternuts, and potatoes, combined with wastewater (WW) from a local fruit and vegetable market, using activated sludge (AS) as the inoculum. The biomethane potential test (BMP) was performed in 1L capacity digesters with an 80% working volume and maintained at 40℃ over a 21-day period. A mixing ratio of 1:1 (% w/w) between WW and AWs and 1:2 between the co-substrates and inoculum was utilized. Biogas production was monitored daily to evaluate the effectiveness of the Co-AD process. The control group yielded a total production of 450 mL/day, while the apple and banana substrates demonstrated the highest biogas output at 595 mL/day and 585 mL/day, respectively. The potato substrate generated 525 mL/day, mixed AWs produced 485 mL/day, and butternut and carrot substrates resulted in 485 mL/day and 475 mL/day, respectively. These findings suggest that the Co-AD of AWs and WW, in combination with AS, presents a viable and eco-friendly approach to enhanced biogas production.