This document summarizes a presentation on cognitive green communications. The presentation covered the concept of cognitive green radio communications and approaches for achieving energy savings within cellular mobile networks in practice. It discussed how traffic patterns in cellular networks are predictable and variable. Reinforcement learning techniques like actor-critic learning and transfer learning were presented as ways for base stations to learn and make decisions to optimize energy savings by switching on and off based on predicted traffic loads. Simulations showed these learning approaches can achieve greater energy savings than state-of-the-art methods.