There is a significant effort to make transition from the traditional DWDM based network infrastructure to the next generation one based on dynamic and elastic optical networking. Such a networking will have multidimensional nature with respect to arrangement of the spectral and spatial signal components, where each component is based on a multidimensional coded modulation. The employment of multiple degrees of freedom offers significant opportunities for the energy efficient transmission of information bits. In this paper, we consider the energy aspects of the elastic networking based on the optical orthogonal frequency division multiplexing (OFDM), optical spatial mode multiplexing, and multidimensional coded modulation. The adaptive optimization approach can lead to a substantial increase in the energy efficiency for high spectral density cases.