Decentralised energy systems are crucial migrating towards cleaner systems. The main advantage is the adjustability to energy demand and supply. A key aspect to promote decentralised energy systems is the integration of flexible technologies in terms of scale and capability to process a wide range of materials including Municipal Solid Waste (MSW). The Waste-to-Energy (WtE) technologies are a strategic factor for planning decentralised energy systems. Among thermochemical WtE technologies, incineration appears to be the most mature. On the other hand, gasification is an emerging technology with the potential to convert a broad range of wastes into useful energy products. The purpose of the study is to provide insights for the planning of decentralised WTE energy systems from MSW. Incineration and gasification are compared by a multidimensional analysis through a systematic review. Findings indicate that decentralised WtE energy systems could meet part of energy demand reducing environmental impacts. Although incineration delivers steady energy production, its feasibility depends on the scale. Gasification offers pliability in the scaling-up process and energy storage. Gasification requires being tested on a commercial scale. Decentralised WtE energy systems provide a platform for emerging technologies through public-private partnerships. Critical success factors include adaptability of technologies and business models.