The traditional paradigm of centralised electricity systems is being disrupted by increasing levels of distributed generation. It is unclear as to what level of distributed generation is expected, appropriate or optimal in future power systems. Many researchers have focused on how to integrate distributed generation into centralised electricity systems. Such research tends to consider optimality from narrow viewpoints focused on particular aspects of the electricity network such as the distribution network within the confines of a vision of future electricity systems where centralised infrastructure remains. There is a gap in the literature in considering the role of distributed generation (DG) within the context of the entire electricity system and the wider energy sector and how it can drive the development of an electricity system to maintain a centralised approach or increase decentralisation. This paper explores the factors that influence the role of DG in future electricity systems and the existing tools that can be used to explore how these factors can impact the role of DG considering four future visions for electricity systems each with increasing levels of decentralisation. The review concludes that there is no one tool that can be used to explore all of the factors and their impact on the role of DG. (C) 2018 Elsevier Ltd. All rights reserved.