Smart cities are a very promising concept for achieving the sustainability of urban settlements. This is especially true for sustainability related to general aspects of energy management, e.g., generation, transformation, distribution, and storage. Despite their considerable potential, smart cities are complex systems in nature, as numerous individuals and subsystems participate in their performance. Because of this complexity, numerous challenges are presented for the conception of this type of system, i.e., during its design stage. The contribution provides a brief literature review that focuses on energy management in smart cities. Initially, an overview of the field is provided by analyzing the co-occurrence of keywords in the literature available in the SCOPUS database. Subsequently, strategies for energy management in smart cities, modeling approaches, and challenges and opportunities are discussed. For this, the work refers to earlier literature reviews that describe in detail relevant subjects from the perspective of networks design and optimization. The review aims at helping interested readers recognize the systematic tools available for the design of energy systems as well as the challenges offered in this rapidly evolving area, thereby contributing to the advancement of sustainable and efficient energy solutions within the context of urban environments.