Energy, which is of primary importance in ensuring the development, welfare, and progress of countries that deeply affect their economies, has recently become one of the most strategic tools. In particular, while the demand for energy in the world is growing strongly, a critical need for sustainable alternative effective solutions has emerged when combined with the increasing waste production. The waste-to-energy (WtE) approach offers a promising solution in terms of both environmental protection and new energy strategies by converting various types of waste, such as industrial by-products, municipal and industrial solid waste, and agricultural residues, into energy sources. This chapter explores the latest advancements in waste-to-energy (WtE) technologies, examining their efficiency, environmental impact, and economic viability. Additionally, it delves into the integration of artificial intelligence (AI) and machine learning (ML) algorithms to enhance these processes. Additionally, this section addresses issues such as improved nano-waste management practices, the integration of renewable energy systems, and the role of economic and environmental solutions in reducing energy dependency. Modern sustainable energy systems are discussed, and it offers information on how to potentially lower carbon footprints worldwide.