Increasing population, technological developments and rising living standards have increased the need for energy. The increasing rate of negative environmental effects caused by a heavy use of fossil fuels and their unsustainable nature has brought up the renewable energy sources as an important alternative. However, one of the most significant obstacles in implementing renewable energy technologies is their fluctuating nature and hence their discontinuity. For this reason, there is a strong need for development of viable energy storage technologies and innovative approaches to offset the mismatch between demand and supply and eliminate possible irregularities, while producing power and covering the needs for heating and cooling, which are closely linked to the energetic, environmental, economic and political dimensions. In this regard, the “Energy Working Group” established within the Turkish Academy of Sciences (TUBA) organized both a workshop and a panel discussion session on “Energy Storage Technologies” to bring all parties together, particularly experts and representatives from universities, private sector and government offices and discuss the respective technologies by considering the key challenges, opportunities and future directions. This particular report is a direct outcome of the delivered talks, expert discussions and literature assessments within the scope of the workshop. In the first part of the report, energy consumption statistics are presented comparatively for both Turkey and the World, and the projections are made for future where the need for energy storage technologies is highlighted. In the second part of the report, energy storage methods are classified based on their types and uses and discussed from the viewpoints of capacities and applications. Various energy storage technologies, namely thermal energy storage, cold energy storage, sensible and latent heat storage, compressed air storage, pumped hydro storage, power to gas type storage, electrical storage, battery storage, chemical storage and hydrogen storage, are discussed, evaluated and assessed for practical applications. Also, research, innovation and technology development efforts exerted in the area by various sectors, such as academia, industry and government, are presented as case studies. The last part of the report focuses specifically on renewable energy investments in Turkey, small- and large-scale energy storage systems and applications, current challenges, opportunities and future trends in the area, and recommendations for a more sustainable future. Furthermore, various policies and strategies are proposed about how to increase the energy storage investments and implementations and successfully perform research, product development, innovation and technology development.