Given energy shortage and environmental issues, nano-energy has attracted many attentions worldwide. This article divides nano-energy technology into eight sub-fields and explores the overall distribution, structural distribution, temporal distribution, geographical distribution and hotspot technologies of each nano-energy sub-field using patentometric method based on nano-energy patent data during 1991-2015 collected from Derwent Innovation Index database. We find that technological activities in each subfield present imbalance development, and China, USA, Japan and South Korea are technological leaders, but there are differences in technological capacities and hotspot technologies in each field. China needs to consolidate and enhance existing technological advantages to achieve balanced progress in nano-energy field in the future.