"I want more green suppliers, but won't pay more for green"

I had a useful conversation with a purchasing executive responsible for $1B of purchases for a large, global manufacturer. He was explicit about his purchasing/selection criteria of demanding of more and more "green" (especially lower in energy use) in products and suppliers, but he is not willing to pay more for it. For him, "green" is a more frequent capability of successful suppliers awarded contracts. An important trend for suppliers to monitor.