This lecture explores the importance of energy in society, covering its role in providing living comfort, fabricating goods, enabling mobility, and supporting communication. It delves into human energy needs, the gift of nature in energy provision, and the energy density of various storage methods. The lecture also discusses the challenges of managing fossil-based energy systems, emphasizing the need for high storage density and integrated supply chains to address intermittent demand and resources. Additionally, it highlights the threat posed by fossil CO2 to humanity.