1. An undesirable phenomenon of PV device operation whereby one or more cells within a PV module or array act as a resistive load, resulting in local overheating or melting of the cell(s).
2. A hot-spot consists of a localized overheating in a photovoltaic module. It appears when, due to some anomaly, the short circuit current of the affected cell becomes lower than the operating current of the whole, giving rise to reverse biasing, thus dissipating the power generated by other cells in the form of heat.
failures of photovoltaic modules
https://www.solar-electric.com/learning-center/general-solar-information/photovoltaic-solar-power-glossary.html (1.); https://arxiv.org/ftp/arxiv/papers/1411/1411.0621.pdf (2.)
Author: Thomas D.