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Saudi Arabia has developed Saudi Vision 2030, an ambitious plan to reduce the country’s dependence on oil by supporting promising private energy organizations and by developing opportunities that contributes to the national economy. In the manufacturing sector, the government is encouraging technology transfers in the renewable energy industries. It is expected to result in the localization of significant parts of the renewable energy value chain in Saudi Arabia. Solar energy systems are proven renewable energy source globally and domestically, it has its long and vast share of experience, from operations and maintenance, to solar data monitoring and gathering. Wide areas had been identified, where this technology can be highly installed and integrated. Components can be manufactured from locally available raw materials to achieve the final products. This study analyzed the key elements of the value chain for producing crystalline silicon solar photovoltaic systems. This paper presents recommendations for localizing this industry in the Kingdom of Saudi Arabia to align with the goals of Saudi Vision 2030. Although these recommendations are based on the environmental conditions of Saudi Arabia, such are also highly relevant for further application to other countries in the Middle East and North Africa region, where widespread energy transitions from fossil fuels to renewable resources are already taking place.

The world’s oldest, and still functional, Concentrator Photovoltaic (CPV) power plant originally rated at 350 kW, and is situated 50 km from Riyadh, Saudi Arabia. There are ongoing efforts to retrofit the modules with new secondary optics and triple-junction cell devices. The paper characterizes the initial optical train, whose design is non-conventional in its use of a two-area primary Fresnel lens. The first generation of a retrofit receiver package is described. Challenges beyond the optical design are encountered, including tracking and structural mechanics.The world’s oldest, and still functional, Concentrator Photovoltaic (CPV) power plant originally rated at 350 kW, and is situated 50 km from Riyadh, Saudi Arabia. There are ongoing efforts to retrofit the modules with new secondary optics and triple-junction cell devices. The paper characterizes the initial optical train, whose design is non-conventional in its use of a two-area primary Fresnel lens. The first generation of a retrofit receiver package is described. Challenges beyond the optical design are encountered, including tracking and structural mechanics.

Here we present results highlighting the differences that soiling and cleaning have on concentrated photovoltaic arrays (CPV) specifically focusing on ultra high concentration, >1000 Suns, photovoltaic (UHCPV) arrays in a desert environment. Soiling losses in UHCPV arrays differ from those of conventional photovoltaic (PV) arrays, to illustrate this difference we present a direct comparison between a UHCPV array and a conventional PV array showing that soiling has an approximately five times larger effect on the UHCPV array compared to a PV array. The soiling effect has been measured by taking current–voltage curves of the arrays and monitoring the power output of a system’s photovoltaic inverter before and after cleaning. The results indicate that in a desert environment there will be some extreme weather events that require cleaning of all types of PV modules. They also indicate that even if it is not economically feasible to clean a PV system, that a CPV system is different enough in its response to soiling and cleaning that further studies and modeling are warranted. We also discuss our current cleaning process, dust prevention methods, and cleaning schedules in an attempt to stimulate further study in these areas.

Reduced optical transmittance of encapsulants resulting from ultraviolet (UV) degradation has frequently been identified as a cause of decreased PV module performance through the life of service in the field. The present module safety and qualification standards, however, apply short UV doses only capable of examining design robustness or “infant mortality” failures. Essential information that might be used to screen encapsulation through product lifetime remains unknown. For example, the relative efficacy of xenon-arc and UVA-340 fluorescent sources or the typical range of activation energy for degradation is not quantified. We have conducted an interlaboratory experiment to provide the understanding that will be used towards developing a climate- and configuration-specific (UV) weathering test. Five representative, known formulations of EVA were studied in addition to one TPU material. Replicate laminated silica/polymer/silica specimens are being examined at 14 institutions using a variety of indoor chambers (including Xenon, UVA-340, and metal-halide light sources) or field aging. The solar-weighted transmittance, yellowness index, and the UV cut-off wavelength, determined from the measured hemispherical transmittance, are examined to provide understanding and guidance for the UV light source (lamp type) and temperature used in accelerated UV aging tests.

We describe a process for increasing power efficiency of concentrator photovoltaic systems by optimizing the lens-to-cell spacing. We find that there is an optimum defocus position with improved power output and reduced sensitivity to pointing errors, which in combination can result in a more than 10% enhancement. The improvement can be realized by minor changes to module cases which should not require changes to other manufacturing, installation, or component costs. In fact optimizing the defocus position allows for lower costs per unit power due to increased power and relaxed system tolerances. The paper focuses on detailed data illuminating the behavior of ultra high concentration photovoltaic modules. While one can look forward to optimizing defocus through sufficiently detailed simulation, at present, we find that an empirical determination of optimum defocus is necessary. The data reveals that even without design parameters changing, supply chain changes can have a significant impact on the optimum defocus - data from five different module configurations with components from different manufacturing lots are presented. These different configurations serve to illustrate the consequences of component changes and the importance of verifying the optimum defocus. A discussion of the effects that are important to determining the optimum defocus and which underlie these differences is included.

King Abdulaziz City for Science and Technology (KACST) in collaboration with IBM has developed the first manually manufactured concentrator photovoltaic (CPV) modules. A single CPV module is rated at 120 W at nominal operating test condition (NOTC) of 1000 W/m2 direct normal insolation (DNI) and 25°C ambient temperature. Two trackers are installed and operated in the solar village outside Riyadh and one located in the eastern coastal city of Alkhafji. Figure 1 shows the trackers in Solar Village and Alkhafji. Valuable lessons were learned after three years of operating the systems on sites with different environmental characteristics. A production process flaw that caused cell material weakening and falling of light pipes from the cell have caused huge output degradation. Other factors that improved module performance are modification of production methods, integrating and replacing new parts. The Fresnel lens was replaced with a higher transmission efficiency lens of the same make as the former. Focal length of the new lens was determined and a new aluminum casing with different dimension was produced. This paper discusses in details the manufacturing process of two modules. The modules are essentially the same except for the cell used in each one. Both modules were manufactured using the modified process. New parts have been incorporated. The modules were then installed in the solar village. Data are being collected at a time interval of 10 minutes. I-V curve tests are also being acquired at different environmental conditions. Analysis and comparisons of these modules with one old module shall be presented.

A simulation of forced convection solar heated water system is presented. A computer program is developed consisting of independent subroutines, capable of handling the variation of the collector tube diameter, tube spacing, ambient conditions, material thermal properties, collector and system design optimization. The meteorological data of Riyadh were used as the input in the program to simulate the performance of the collector system. The output of the program is analyzed to optimize the system design in the Riyadh region. The results of the simulations are compared with experimental data. There is a good agreement between the predicted and measured values.

The three year KACST/IBM collaboration in solar technology research led to the design and development of a 10kW CPV system. The system is comprised of 81 PV modules, inverters and a tracking system and is grid connected. A primary and secondary optics were employed to reach 1600x concentration on multijunction solar cells. Two CPV trackers were installed in the city of Riyadh and one in the eastern coastal city of Al Khafji. These two areas differ in climatic conditions. Riyadh is mostly dry and very often hit by very strong sand storms while Al Khafji is very humid with sand storms. Very fine dusts and dirt carried by the storms hits the surface of the primary optics, Fresnel lens, of the system. In Riyadh, the particles stick to the lenses but accumulation in the surface is not much since it is blown away by wind. However, the humid condition of the coastal areas wets the dusts and makes it sticky, cumulating more dusts and dirt. This paper discusses in details the parts of the 10kW CPV system. It presents a comprehensive analysis of the system's performance since the time they were installed and operated. CPV systems are operated with the least number of personnel and supervision. However, dust and dirt lessens the amount of sunlight passing through the primary optics. It requires periodic cleaning of the Fresnel lens. Different methods of cleaning were tried to identify the efficient way to clean the system that results to a higher power generation. Corrections and modifications of the system to further increase power production are presented.

This paper discusses the development and deployment of an ultra-high concentrating PV module that utilizes concentration above 1400X on multijunction solar cells. The development process included the selection of cell assemblies, primary and secondary optics, and focal distance. The systems were deployed in Saudi Arabia inside the Solar Village near Riyadh and in Khafji near the border of Saudi and Kuwait, following the deployment of first prototype in Yorktown, NY. Data from operation in those areas are shown here, and next steps of optimizing the module performance are discussed.

The paper deals with the optimization of the tubular absorber of a compound parabolic concentrator (CPC) solar collector. In order to minimize the radiation thermal losses from the absorber, a modified absorber with multi-cavities is proposed. The cavities are introduced at the circumferential area with relatively high solar intensities. These areas were determined by the use of a ray-tracing technique. This has been adopted using the AutoCAD ® package. The analysis was carried out and applied to a CPC with an acceptance angle of 10 and a concentration ratio of × 4.0.

This communication deals with the raytrace of tubular absorber of the compound parabolic concentrator. In order to investigate the location of the hot spots on the absorber, a raytrace was needed. There were different techniques to achieve an accurate raytrace. One of the technique was adopted is AutoCAD®. The analysis was carried out and applied to a CPC with an acceptance angle of 10° and a concentration ratio of x4.0. The objective was threefold. Firstly, it was necessary to calculate the profile of the CPC and the tubular absorber. Secondly, it was necessary to analyse the distribution of intensity around the circumference of the tubular absorber , Finally, to analyse the phenomena of the rays inside the CPC for different incident angle.

Practical multi receiver ultra high (1000+ Suns) concentration photovoltaic (UHCPV) systems experience large radiation, thermal and electrical loads in addition to large power density transients under routine operation. This report is a summary of the issues involved in determining the practical limits to concentration. How high is too high? Explorations into UHCPV have both theoretical and experimental aspects. Understanding the theoretical device physics and circuit limitations is often essential to determining which experiments to do and in interpreting results. On the experimental side the work can be divided into two fields depending on the type of light source. The first is artificial or simulated sources and the second is working in the field with direct solar irradiation. Both fields have advantages and disadvantages. Direct solar radiation was selected for the current experiments due to the low cost and ability to produce ultra high concentrations (4000+) over relatively large areas (25+ mm2). Several experimental examples from these direct solar measurements shed light on some of the basic theories of how concentrated light affects the performance of multi junction photovoltaic cells. Out of these examples and theoretical foundations we conclude that for practical devices the first order constraint to optimum efficiency at ultra high concentrations is the series resistance. We also present a simple model based on published data and our results that can be used to predict the total system series resistance needed to optimize a system for a particular concentration.

Practical concentrator photovoltaic systems operating at high solar concentration levels up to 2000 suns experience large thermal and electrical loads in addition to large power density transients under routine operation. These systems require efficient cooling systems to manage the associated incident power densities up to 200 W/cm2. Photovoltaic cells and thermal interface materials experience considerable stress under these load conditions. Reliability data is sparse for operation above 500 suns. We present high power test results for a commercial triple junction cell cooled through a high performance metal thermal interface using active liquid cooling methods for power densities up to 200 W/cm2.