Cortec is a service robot concept to increase the efficiency of solar parks. It solves the problem of lack of service personnel and high maintenance costs in the exponentially growing solar industry. Improving solar energy generation not only brings more profit - every solar park can offset thousands of tons of additional CO2 emissions and provide energy for substantially more households. The main part of the robot is the modular vehicle base on which tools for various tasks can be docked. The cleaning tool was the focus of the project, as soiling leads to most losses (5%-40% annually) and the ongoing process offers enormous potential for cost and resource savings. This tool is placed on the modules by a robot arm and cleans the surfaces with the help of water and brushes. A circular system with a filter ensures tremendous water savings. In addition, the design of solar parks as a complete system for autonomous maintenance processes was also considered.