ROWS of solar panels capable of generating 1.2 megawatts of electricity cover 6,000 square meters of the rooftops at Song Hong Garment HSC textile factory in Nam Dinh Province, around 90 kilometers southeast of Hanoi, Vietnam. That Wednesday afternoon, March 15, was cloudy. The rooftop solar power generator (PLTS) could only supply about 30 percent of the electricity needed in the factory. “It is currently not optimal,” said Copper Mo