. . . It has the highest electrical and thermal conductivity of all metals, and it's the most reflective.
. . . These physical properties make it a highly valued industrial metal, especially when used in solar cells.
Silver is actually a primary ingredient in photovoltaic cells, and
. . . 90% of crystalline silicon photovoltaic cells, which are the most common solar cell, use a silver paste.
What happens is that when sunlight hits the silicon cell it generates electrons.
. . . The silver used in the cell, works as a conductor to collect these electrons,
. . . in order to form a useful electric current.
The silver then transports the electricity out of the cell, so it can be used.
. . . Further, the conductive nature of silver enhances the reflection of the sunlight,
. . . to improve the energy that's collected.
Therefore, if it wasn't for silver,
. . . solar wouldn't be as efficient in turning sunlight into energy.
08-29-2014 Source: Silver in Solar