Reducing world-wide energy consumption and ensuring a sustainable planet is a major challenge in the next few years due to the raising economic and environmental effects. Telecommunication market is one of the major contributors to energy consumption in the world. With the expected exponential growth of the market resulting from the increase of data rates with the launch of 5G networks and the mobile devices leading to the spread of the Internet Of Things, the energy consumption of wireless networks is expected to increase dramatically. 5G wireless networks research is gaining momentum with the emergence of new ideas and innovative solutions. Energy efficiency and sustainable solutions are the prime considerations for the 5G networks. Energy harvesting is a promising solution to combat the energy inefficiency problem and make wireless network sustainable. Although the extensive research works with theoretical promise and potentials have been established over the years, practical implementations closing the gap between the theory and practice still need to be addressed. GRASNET workshop addresses energy efficiency and sustainability aspects of the 5G networks from theory to applied nature of the problem.