Japan's Showa Shell unit, Solar Frontier has begun commercial production at its third solar cell plant in southwestern Japan.
The firm will bring the 900MW plant to full production in July 2011, increasing its annual capacity to 980MW.
Solar Frontier has put in an investment of JPY100bn ($1.2bn) to achieve full production.
The firm specialises in solar cells made using copper, indium and selenium that are cheaper than mainstream solar cells made from polysilicon.
Royal Dutch Shell owns one third of Showa Shell, while Saudi Aramco owns 15%.