Even as one-fifth of the nation's electrolytic aluminum capacity lies idle, producers are adding new facilities - a combination that will mean a glut of the metal next year and falling prices, industry experts said on Tuesday.

"China is facing severe overcapacity in the electrolytic aluminum sector, with a low utilization rate," said Wen Xianjun, deputy chairman of the China Nonferrous Metal Industry Association.

The capacity utilization rate is about 78 to 80 percent at present, according to the association.