The worldwide increased knowledge of the environment and the risk of exhausting non-recoverable energy sources is a reason that various methods of using alternative resources have been sought. Solar energy is an inexhaustible source which, thanks to the programmes for the support of the construction of solar power plants is most often used. The need for problem-free operation of such a power plant is high-quality assembly, as well as regular maintenance and inspection of all panels. A fast, cheap and reliable method where it is possible to check the quality of a large area of solar panels is thermodiagnostics using the Workswell WIRIS thermal imaging system attached to the drone.