Accelerators are a type of incubation program that are concerned with attracting, supporting and developing new ventures. Although there is significant enthusiasm for accelerators and their potential benefits, there is limited research on how their core capabilities can vary. In response, we develop a typology of accelerator capabilities taking into account their strategy, governance, business model, operations and finance. To develop the typology we carried out a benchmark analysis of six clean energy commercialization accelerators (CECAs). From this we verified and illustrated the dimensions of our typology and identified four types of accelerator capabilities: R&D focused, technology enabled, market enabled, and network enabled. We then use a seventh accelerator case to illustrate how our typology can be used to describe, understand and prescribe appropriate capabilities for a CECA. We conclude our paper by explaining the research and practice implications of our research.