Innovation of clean technologies is critical to mitigating increasing environmental challenges, while it can generate revenues for the inventing firms and beyond through technology spillovers. However, the extent to which clean technologies are generating private and social economic benefits remains poorly understood to date, due to a lack of suitable data sources. Using a unique dataset disaggregating commercial activities of global publicly listed firms based on a new green taxonomy, this paper shows the variation of green revenues during 2009-2016. We document a smooth increase in average green revenues over years. This increase is mainly driven by the expansion of revenues from green products but not the structure change between green and non-green revenues. We find that firms’ green revenues are enhanced by not only their own clean innovation but clean technology spillovers from other neighbouring firms close in the technological and product market spaces. We also find that the growing maturity of clean technologies facilitates firms to obtain more green revenues, particularly for firms with more own clean technologies. Firms with larger sizes and higher technology capacities benefit more from their own and others’ clean innovation. The new evidence on clean technology spillovers implies considerable social benefits of clean innovation and the need to provide policy support to encourage investments in clean technologies.