Effects of soiling on photovoltaic (PV) modules in the Atacama Desert

Abstract

Soiling by dry deposition affects the power output of photovoltaic (PV) modules, especially under dry and arid conditions that favor natural atmospheric aerosols (wind-blown dust). In this paper, we report on measurements of the soiling effect on the energy yield of grid-connected crystalline silicon PV modules deployed in five cities across a north-south transect of approximately 1300 km in the Atacama Desert ranging from latitude 18°S to latitude 30°S. Energy losses were assessed by comparing side-by-side outputs of four co-planar PV modules. Two of the PV modules of the array were kept clean as a control, while we allowed the other two to naturally accumulate soiling for 12 months (from January 2017 to January 2018). We found that the combination of high deposition rates and infrequent rainfalls led to annual energy losses that peaked at 39% in the northern coastal part of the desert. In contrast, annual energy losses of 3% or less were measured at relatively high-altitude sites and also at locations in the southern part of the desert. For comparison, soiling-induced annual energy losses of about 7% were measured in Santiago, Chile (33°S), a major city with higher rainfall frequency but where urban pollution plays a significant role.

Extremophilic microbial communities on photovoltaic panel surfaces: a two‐year study

“…A study performed on subaerial solar panel biofilms in São Paulo revealed that dust, pollen and other debris covering the solar panel surfaces accumulated in time and included abundant fungi and pigmented bacterial genera, and this was associated with a decrease in the photovoltaic power efficiency, especially after 12 and 18 months (loss of 7% and 11% power respectively) (Shirakawa et al ., 2015). This process – the accumulation of dust particles and microorganisms on a surface – is known as soiling, and it affects photovoltaic efficiency especially under dry and arid conditions, such as those in the Atacama Desert, resulting in an annual energy loss of up 39% in regions with infrequent rainfalls (Cordero et al ., 2018).…”

Techno-Economic Assessment of Soiling Losses and Mitigation Strategies for Solar Power Generation

“…In comparison to soiling rate studies, there are only a few scientific reports on common cleaning economics and costs with regard to PV soiling. 9,22,51,[115][116][117][118][119][120][121][122][123][124][125][126] The outcomes of these studies are difficult to compare, as they mostly report on soiling economics for a particular site (sometimes without optimization), use complex model approaches that are not easy to reproduce or are based on limited or outdated data. Therefore, information on cleaning costs has been compiled from industry partners and stakeholders, indicating huge differences between the different countries and different sites and plant sizes (see Figure 2C).…”

Techno-Economic-Environmental Impact of Derating Factors on the Optimally Tilted PV System

“…to examine the performance of a 720Wp PV system. Rainfall plays a vital role in removing soiling from the PV panels, as pointed out by several studies [41]- [43], which eventually improves the PV output efficiency. Dirt and dust can be cleaned up in the rainy season in Bangladesh, but this period is getting decreased recently.…”

“…Apart from these, power conditioning unit (inverter), transformers, and sun-tracking also affect the AC power rating of the gridcoupled PV system [40]. However, existing literature mostly discusses the technical effect of derating factors on the PV system [26], [28], [31], [32], [41]- [45]. Very few studies are available pointing out the economic effect of a single derate factors such as soiling, shading, degradation, and PV tracking along with technical impact [14], [19], [27], [46]- [48].…”