Nissan Motor Co.'s Oppama plant, which makes the zero-emission Leaf, is a showcase for the Japanese automaker's ambitions to be a green leader while keeping production in Japan.

The plant was shown to reporters Tuesday. The factory, which employs 1,860 workers and has added 225 temporary workers, is now making about 2,000 Leaf cars a month.

But Nissan is making efforts to double that to 4,000 a month at Oppama sometime this year, although Senior Vice President Toshiharu Sakai declined to say exactly when.