An additional interface was implemented in the data logger for communication between the energy trader and the remote controlled PV system. The prerequisite for enabling the energy trader to sell solar energy on the electricity exchange based on the market bonus model is thus bundled in one device. The trading interface supports implementation of commands for reducing the active power of the PV system, in addition to supporting feedback to the energy trader about the current status of the feed-in power. To safeguard data communication between the monitoring system of the PV system and the respective energy trader, the communication line is protected via VPN encryption.