## 2 Importance of Thermal Condition Monitoring  
### Attributes of Thermal Condition Monitoring  
Renewable energy distributed generation development is challenged with enormous constraints for successful integration. Irregular generation capacity thresholds or high demand side load may increase the nominal system power beyond set points. This condition may exceed the thermal impact limit. The network components of intrinsic characteristics may also contribute to the DERs thermal constraints. The temperature profiles of the subsystems significantly contribute to the existence and life expectancy of the DERs grid. Moreover, adverse thermal conditions violate the protection of functioning mechanisms in the network configuration. Proper use of the monitoring system for thermal behavior aids in controlling the conditions of the network components. The achievement of the DERs status is possible by online and real-time data profiling and prompt maintenance scheme development. The maintenance strategies may be in a form to control generation sources temperature, control schemes to minimize harmonics development, and load management at the demand side. Knowing the thermal condition of the DERs network is an essential and reliable indication of an integrated distributed power grid status. The sudden increase in temperature of the system may indicate system overloading, development of harmonics, deprived passive or active cooling of generation resources, ineffective lubrication, and possibly severe weather fronts [19; 20]. The need for improving the DERs integrated grid thermal conditions monitoring motivates the concept of measuring system components status. The literature indicates that aspects of distributed renewable power generation predicaments are from thermal constraints during operations. The constraints cause events involving materials heat characteristics and the components configuration failures. These increase temperature thresholds due to the behavior of the components influence on a system with thermal impact performance. The development again causes system thermal effect, which leads to power generation and delivery impairments. Further, the thermal effect affects electric power consumers of the required energy needed for reliable performance [19; 21; 22]. Photovoltaic components made from semiconductor materials, which have the properties of photoconductivity, suffer from thermal effect. The electrical conductivity of the PV cell is affected by the exposure to electromagnetic radiation (sun/light). The semiconductor material releases electrons which are present between its conductor and insulation domains. The generated tension for the release of the electrons between semiconductor domain regions of \"P\" and \"N\" causes electric power production from solar PV cells. However, recombination occurs within the semiconductor material during which a free electron could bounce back to become an atom. This recombining electron does not contribute to the production of electrical current. It develops incident solar energy, which creates heat as wasted energy. The incident solar energy of the PV panel creates convection and radiated heats, which anticipate being cooled by the air current. Should the temperature of the cooling air not be active, the wasted energy seeks to be absorbed by the PV cells and develops opposing characteristics to current. The same scenario happens in the power electronics inverters. This phenomenon then impedes effective power collected and affects the energy conversion efficiency of the solar PV panel and power electronics inverters performance [10; 12; 23; 24]. Additionally, the higher proportion of the solar irradiance absorbed by the PV module does not commensurate as electric energy; conversely, it creates an increase in the temperature of the PV module, hence reducing the PV efficiency. Moreover, the temperature of the PV module is influenced by numerous factors such as heat dissipation of the material, the module packaging criteria, and the PV module installation procedures.