One of the few bright spots in the dark days of the global economic downturn is the field of renewable energy.

The industry's strength was in evidence at the 5th International Hydrogen and Fuel Cell Expo, which kicked off Wednesday at Tokyo Big Sight in Koto Ward.

A total of 925 domestic and overseas companies operated booths at this and a concurrent exhibition, the 2nd International Photovoltaic Power Generation Expo, up from 768 companies last year.