How are EB and ODE calculated if I feed back to the energy grid?

This depends on the type of connection. With a small consumer connection, netting takes place. This means that the feed-in is deducted from the supply. You only pay EB and ODE on the remaining supply (consumption). If the feed-in is higher, you do not pay any EB and ODE. This balancing scheme does not apply to high-volume connections.