Changes to solar panel technology are accelerating demand for silver, a phenomenon that is widening a supply deficit for the metal with little additional mine production on the horizon. Silver, in paste form, provides a conductive layer on the front and the back of silicon solar cells. But the industry is now beginning to make more efficient versions of cells that use a lot more of the metal, which is set to boost already increasing consumption. Accelerating demand for solar panels is putting the global supply for silver under pressure. AP Solar is still a fairly small part of overall…