This exploratory case study finds evidence that the development of a storage technology niche in Ontario is being strategically managed through different stages by stakeholders within the system. It suggests that the complementary relationship between storage innovations and smart grid transitions supports the strategic management of a storage niche. It also suggests that the development of this niche supports the electricity system transition to smart grid. The study employs the Technology Innovation System (TIS) and Strategic Niche Management (SNM) analysis frameworks predominantly used by authors to study systems in Europe. By presenting empirical data from a jurisdiction outside of Europe, this research contributes to the growing theory on the formation of niches and the influence of complementarity on innovations in large technical systems. It also offers insights to practitioners within this sector, including the new entrants, incumbents and policy makers. Further research is recommended to determine the generalizability of these findings.