But EVs still only account for 1% of the total market.

Some companies are betting that hydrogen fuel cells will be the power source of the future, but Nissan believes bio-ethanol produced from sugar cane or corn could also produce zero-emission electric energy.

Nissan recently unveiled its prototype solid-oxide fuel cell vehicle in Brazil, where ethanol is readily available in all gas stations - in marked contrast to hydrogen pumps.

But Nissan boss Carlos Ghosn says the success of the concept will largely depend on political support.