The green change at more than 80 GM factories is not only environmentally friendly but is expected to generate millions of dollars from sales of scrap metal and recycled materials, The Detroit News reported Saturday.

"Environmental performance is linked to financial performance," said John Bradburn, a GM

environmental engineer.

Currently, GM has 43 manufacturing facilities that are are considered landfill-free -- meaning they recycle or reuse more than 96 percent of waste materials -- with an additional 3 percent converted to energy at the sites. GM makes about $1 billion a year from selling scrap metal at present, along with $16 million more from selling recycled cardboard, wood, oil, plastic and other materials.