Dust effects on PV array performance: in-field observations with non-uniform patterns

ABSTRACTThis paper presents the impact of non‐homogeneous deposits of dust on the performance of a PV array. The observations have been made in a 2‐MW PV park in the southeast region of Spain. The results are that inhomogeneous dust leads to more significant consequences than the mere short‐circuit current reduction resulting from transmittance losses. In particular, when the affected PV modules are part of a string together with other cleaned (or less dusty) ones, operation voltage losses arise. These voltage losses can be several times larger than the short‐circuit ones, leading to power losses that can be much larger than what measurements suggest when the PV modules are considered separately. Significant hot‐spot phenomena can also arise leading to cells exhibiting temperature differences of more than 20 degrees and thus representing a threat to the PV modules' lifetime. Copyright © 2013 John Wiley & Sons, Ltd. The impact of non‐homogeneous deposits of dust on the performance of a PV array is presented. The results are that inhomogeneous dust leads to larger power losses when the affected PV modules are part of a string together with less dusty ones than when considered separately. Voltage losses can arise and be several times larger than the ones resulting from the transmittance decrease. Hot‐spot phenomena with temperature differences of more than 20 degrees can also appear.