The field experiments and model of the natural dust deposition effects on photovoltaic module efficiency

Creating wildlife habitat using artificial structures: a review of their efficacy and potential use in solar farms

The biodiversity crisis is exacerbated by a growing human population modifying nearly three-quarters of the Earth's land surface area for anthropogenic uses. Habitat loss and modification represent the largest threat to biodiversity and finding ways to offset species decline has been a significant undertaking for conservation. Landscape planning and conservation strategies can enhance habitat suitability for biodiversity in human-modified landscapes. Artificial habitat structures such as artificial reefs, nest boxes, chainsaw hollows, artificial burrows, and artificial hibernacula have all been successfully implemented to improve species survival in human-modified and fragmented landscapes. As the global shift towards renewable energy sources continues to rise, the development of photovoltaic systems is growing exponentially. Large-scale renewable projects, such as photovoltaic solar farms have large space requirements and thus have the potential to displace local wildlife. We discuss the feasibility of 'conservoltaic systems' - photovoltaic systems that incorporate elements tailored specifically to enhance wildlife habitat suitability and species conservation. Artificial habitat structures can potentially lessen the impacts of industrial development (e.g., photovoltaic solar farms) through strategic landscape planning and an understanding of local biodiversity requirements to facilitate recolonization.

A comparison of dust impacts on polycrystalline and monocrystalline solar photovoltaic performance: an outdoor experimental study

Solar cells are considered one of the most important and widespread solar applications in the world. However, the performance of the PV modules is significantly affected by the dust in the air. This paper, therefore, presents a comparison of an outdoor experimental study of dust effect on monocrystalline, and polycrystalline photovoltaic (PV) modules. For analysis, four 100 W PVs were installed horizontally in Sohar, Oman. For each pair of PV modules, one was left dusty due to environmental impact, and the second was cleaned daily. PV performance and environmental parameter measurements were conducted every 30 min for 35 days. The effects of dust on current, voltage, power, and energy were discussed in terms of time and normalized values. Also, cleaning methods were tested to determine the optimum one. It is found that power degradation of monocrystalline (20%) is higher compared with polycrystalline (12%) due to dust accumulation. For monocrystalline, the current, voltage, and power losses ranged between 10.0-24.0%, 2.0-3.5%, and 14.0-31.0%, respectively. However, for polycrystalline, the degradation rates were 16.88-27.92%, 0.455-0.455%, and 17.14-28.1% for current, voltage, and power losses after exposure to outdoor conditions for the same period, respectively. The dust accumulation on the PV surface found after 5 weeks is 0.493 mg/cm², which can be considered the lowest accumulation rate compared to other Gulf countries, but which, however, leads to less energy degradation as well. It is found that water is sufficient to clean PV in the study area. However, sodium detergent as a cleaner introduced better results compared to water, especially when there is high pollution in the location.

Thermal modeling, characterization, and enviro-economic investigations on inclined felt sheet solar distiller for seawater desalination

Sustainable desalination can be achieved by adopting renewable energy-based low-cost and low-impact desalting techniques. In this investigation, capability of inclined felt sheet solar distiller in desalting seawater is assessed by evaluating its performance, distillate water quality, economics, and environmental impacts. The distiller with 1.18-m² aperture area produced around 4.60 L/day of distillate for a cumulative incident solar radiation intensity of about 20.52 MJ/m² day. Its pollutant removal efficiency is very much superior to other available solar stills reported in literatures. Thermal model developed for estimating distiller's performance is able to predict its productivity with reasonable accuracy (only 8.0% deviation from experimental values) and was used for estimating distiller's performance in various seashore locations in India with varying clear days (191 to 246). Yearly mean distillate production and thermal and exergy efficiencies of the proposed distiller range between 3.60 to 4.50 L/day, 36.45 to 42.39%, and 2.85 to 3.65%, respectively, in east seashore locations of India. Moreover, 18.46 tons of CO₂, 132.72 kg of SO₂, and 54.20 kg of NO emission can be mitigated by adopting the distiller for potable water production. Distillate production cost of inclined felt sheet solar distiller is in the range of 1.15 to 2.29 INR/L and highly depends on the interest rate at which the distiller is financed. Generation of reasonable quantity of high-quality potable water at low cost with huge environmental benefits makes proposed inclined felt sheet solar distiller a suitable option for quenching thirst in coastal and remote locations.

Impact of wind on strength and deformation of solar photovoltaic modules

Maritime transport is one of the most important modes of transportation and plays an important role in facilitating world trade. In recent years, the maritime transport industry has been required to comply with "low carbon" policies. To meet the "low carbon shipping" policies, solar energy as a source of renewable energy has attracted more attention in the shipping industry. Photovoltaic solar panels, which to generate ships' electricity, are always vulnerable to wind damage because they are mounted on deck. At present, they do not provide comprehensive guidelines for reducing the impact of wind on photovoltaic structures. The present study contributes to the evaluation of the deformation and robustness of photovoltaic module under ocean wind load according to the standard of IEC 61215 using the computational fluid dynamics (CFD) method. The effect of wind on photovoltaic panels is analyzed for three speeds of 32 m per second (m/s), 42 m/s, and 50 m/s.

Soiling Effect Mitigation Obtained by Applying Transparent Thin-Films on Solar Panels: Comparison of Different Types of Coatings

Dust accumulation on the front cover of solar panels is closely linked to location and orientation of photovoltaic (PV) installation. Its build-up depends on the module tilt angle, frequency of precipitation, humidity, wind strength and velocity, as well as grain size. Additionally, soil composition is determined by solar farm surroundings such as local factories, agricultural crops, and traffic. Over time, molecules of atmospheric dust agglomerate on top of each other and cause gradual reduction in generated energy. Manual cleaning techniques are required to restore working conditions of PV installation to their original conditions; however, they are time consuming and may lead to damage of the glass coverage. Therefore, implementing a different approach by utilizing self-cleaning and anti-dust coatings on front covers of module surfaces is thought of as a competitive manner of cleansing. Based on the varying properties of such thin-films, a division was made into hydrophobic, hydrophilic, and anti-dust coatings. In this article, the authors would like to present a comprehensive review of those types of transparent films. Moreover, a few hydrophobic coatings available on the Polish market were analyzed by applying them on glass tiles and covering them with three types of dust.

Assessment of soiling effect on PV module glass transmittance in Moroccan capital region

This work is a first part of the study in development on the mapping of soiling losses in the region of Rabat-Sale-Kenitra in Morocco. To perform the work, two holders of glass samples have been constructed and installed in two different sites of Sale City for three successive periods (from April to June 2019). At the end of each period, the transmittance losses of the glass samples as well as the mass of deposited soils are systematically measured. SEM (scanning electronic microscopy) analyses are also performed for more investigation and deep understanding. The obtained results show that the relationship between soil mass density and glass transmittance loss is not always linear as could be expected. They also show that soiling losses are strongly depending on the environment and nature of the surrounding installation spaces. The SEM analysis results of the 1st period and the inclined surfaces have shown that particles are greater in the range of 2-11 μm and the majority tends to have a regular shape in the two sites. Nevertheless, the frequencies are different. From this study, it can be concluded that it is highly recommended characterizing the site where soiling measurements are conducted not only by its location/city but also by its environment characteristics.

Researches of the Impact of the Nominal Power Ratio and Environmental Conditions on the Efficiency of the Photovoltaic System: A Case Study for Poland in Central Europe

The paper analyzes a case study of the impact of changing the nominal power ratio (NPR) on the efficiency of a PV (photovoltaic) system located in Poland. In the first stage of the research, the acceptable range of variability for NPR was determined based on simulation calculations, taking into account the parameters of PV modules, inverter, and climatic conditions. The second stage was verification tests for two acceptable extreme cases, carried out based on the analysis of detailed data from the monitoring of PV installations. The results of the verification tests for the two considered periods of operation of the PV system with the change of the NPR coefficient from 82% to 98% resulted in an increase in the annual energy yield by 446.2 kWh. On the other hand, higher relative values of generated energy were obtained only for the months with the lowest insolation in December and in January by 8.2 and 6.04 kWh/kWp, respectively. Higher oversizing of the PV generator (for NPR = 82%) also resulted in an increase by 6.4% in the frequency of operation of the PV inverter in the largest power range (2250–2500 W) and a decrease by 3.7% in the frequency in the lowest power range (0–250 W) for the whole year.

An investigation of the dust accumulation on photovoltaic panels

The particle deposition on the surface of solar photovoltaic panels deteriorates its performance as it obstructs the solar radiation reaching the solar cells. In addition to that, it may cause overheating of the panels, which further decreases the performance of the system. The dust deposition on the surfaces is a complex phenomenon which depends on a large number of different environmental and technical factors, such as location, weather parameters, pollution, tilt angle and surface roughness. Hence, it becomes crucial to investigate the key parameters which influence dust accumulation and their interrelations. In this study, the phenomenon of dust deposition was studied experimentally in the urban area at one of the most polluted cities of Europe, i.e. Kraków, Poland. Solar photovoltaic panels tilted at angles 15° and 35° were exposed to atmospheric conditions for the period of eighteen months from 6 May 2017 until 30 November 2018. Dust samples were collected from the panels for the exposure period which ranged from one day up to 11 days. It was observed that lower tilt angles promote dust accumulation on the surface and that in the absence of wind and rain, deposition of particles on the surface of panels follows the pattern of concentration of PM2.5 and PM10 in the atmosphere. Wind and rainfall usually promote the removal of dust particles from the surface. However, rainfall not always aids the cleaning of panels, and it was observed that low-intensity rain results in a very low rate of PMs in the air and in much higher than typical dust deposition on the panel surface. It also accelerates the cementing of already deposited dust. It was only rainfall whose intensity was at least 38 mm/h that was sufficient to remove dust particles from the panels.

Impact of bird dropping deposition on solar photovoltaic module performance: a systematic study in Western Rajasthan

One of the most critical challenges is bird dropping deposition (soiling) on a glass surface of the photovoltaic (PV) module in an open environment of Western Rajasthan. This paper has been now exclusively emphasized to focus on effects of the bird dropping phenomenon on the performance of PV systems. The presented study includes the impact of the seasonal bird dropping effect on the reduction in energy yield with various tilt angle configurations. Considering this, the highest level of reduction in power loss was observed at the end of winter (March) and minimum during rainfall (August) every year. The sitting/walking tendency of birds with the plate inclination directly affects the PV output, which is demonstrated by optical study of glass samples (bird dropping patterns). Consequently, the studies of optical transmittance conclude the effect of dropping with different tilt regions I (β < 25°), II (25° ≤ β ≤ 60°), and III (60° ≤ β ≤ 90°), i.e., explained by bird movement onto the module surface. The result also showed that optimal inclination β (40°) has a smaller soiling effect in tilt region II (25-60°) correspondingly.

A review on the direct effect of particulate atmospheric pollution on materials and its mitigation for sustainable cities and societies

Particulate matter (PM) has gained significant attention due to the increasing concerns related to their effects on human health. Although several reviews have shed light on the effect of PM on human health, their critical adverse effect on material's structure and sustainability was almost neglected. The current study is an attempt to fill this gap related to PM impact on structural materials under the overall consideration of sustainability. More specifically, this review highlights the existing knowledge by providing an overview on PM classification, composition, and sources in different locations around the world. Then, it focuses on PM soiling of surfaces such as solar panels due to an increasing need to mitigate the impact of soiling on reducing photovoltaic (PV) power output and financial competitiveness in dusty regions. This topic is of critical importance for sustainable deployment of solar energy in arid and desert areas around the world to help in reducing their impact on overall climate change and life quality. In addition, this review summarizes climate change phenomena driven by the increase of PM concentration in air such as radiative forcing and acid rain deposition due to their impact on human health, visibility and biodiversity. To this end, this work highlights the role of process management, choice of fuel, the implementation of clean technologies and urban vegetation as some possible sustainable mitigation policies to control PM pollution in cities and urban regions. This research is designed to conduct a comprehensive narrative literature review which targets broad spectrum of readers and new researchers in the field. Moreover, it provides a critical analysis highlighting the need to fill main research gaps in this domain. The findings of this review paper show that PM pollution imposes severe adverse impacts on materials, structures and climate which directly affect the sustainability of urban cities. The advantages of this review include the value of the extensive works that elaborate on the negative impacts of PM atmospheric pollution towards high level of public awareness, management flexibility, stakeholder's involvements, and collaboration between academy, research, and industry to mitigate PM impact on materials and human welfare.