Solar modules are the key components in a PV plant system, and they play a fundamental role in the conversion of solar
radiation and related energy output performance. Even if the solar energy cost is decreasing due to investment in thin-film technology and other developments, it is still high if compared with other sources in many countries. However, in the near future, the cost and efficiency of PV systems can be optimized by appropriate monitoring and maintenance activities both for small- and large-sized plants. In this context, the monitoring with related technological solutions can have a significant impact to obtain the best performance and solutions from the installed capacity.