Communication networks are becoming more essential for our daily lives and critically important for industry and governments. The intense growth in the backbone traffic implies an increment of the power demands of the transmission systems. This power usage might have a significant negative effect on the environment in general. In network planning there are existing planning models focused on QoS provisioning, investment minimization or combinations of both and other parameters. But for designing green optical backbones there is a lack of a model. This paper presents novel ideas to be able to define an analytical model to consider environmental aspects in the planning stage of backbones design.