Soiling and other optical losses in solar‐tracking PV plants in navarra

Abstract

Field data of soiling energy losses on PV plants are scarce. Furthermore, since dirt type and accumulation vary with the location characteristics (climate, surroundings, etc.), the available data on optical losses are, necessarily, site dependent. This paper presents field measurements of dirt energy losses (dust) and irradiance incidence angle losses along 2005 on a solar-tracking PV plant located south of Navarre (Spain). The paper proposes a method to calcúlate these losses based on the difference between irradiance measured by calibrated cells on several trackers of the PV plant and irradiance calculated from measurements by two pyranometers (one of them incorporating a shadow ring) regularly cleaned. The equivalent optical energy losses of an installation incorporating fixed horizontal modules at the same location have been calculated as well. The effect of dirt on both types of installations will accordingly be compared.

Losses produced by soiling in the incoming radiation to photovoltaic modules

“…As we have shown in the last section, soiling on the surface of a photovoltaic module reduces significantly the energy received. As shown in previous studies , these losses should not be constant during the day, but have to be dependent on the angle of incidence. In order to study this dependence, irradiation values sensed by the clean cell and the dirty cell throughout the day are compared.…”

Assessment of PM dry deposition on solar energy harvesting systems: Measurement–model comparison

“…Soiling, or the loss of energy from dust or particulate matter (PM) deposition on the panels, can reduce energy production significantly. Previous studies have found soiling losses between less than 1% (Hottel and Woertz 1942) and more than 88% (Garg 1974), and soiling rates (loss of energy over time) between 0.1% per day (Garc ıa et al 2011) and 5% per day (Sayigh 1978). These large variations in losses can be attributed to location and meteorology, but generalization in the field has not been done.…”

Performance assessment of grid-interactive solar photovoltaic projects under India’s national solar mission

“…There are several technical losses (i. e. optical, array and system losses) associated with PV power project that needs to be estimated and addressed realistically during the EYA [81][82][83][84]. Optical losses are associated with the conversion of solar irradiance (optical energy) through PV modules into electrical energy under specified design approach (tilted or tracking) [85]. Array losses are within the solar module of the DC field which essentially comprises losses due to temperature, quality, mismatch, degradation, cabling etc.…”