Matt DiLallo

The Motley Fool

With a history that dates back more than 5,000 years, silver has been an incredibly valuable metal through the ages. It was once used as a trading currency along the Asian spice routes and was even the standard for U.S. currency for a while. However, the precious metal holds far more value than just as a currency. In fact, more than half of the world's silver is actually used for industrial purposes as it is used in X-rays, low-e windows, and even solar panels. As it turns out, even solar energy wouldn't work the same way if it wasn't for silver.

Making solar shine

Silver is a unique metal. 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.

Shining a light on silver in solar

The average solar panel actually uses about two-thirds of an ounce of silver, which is about 20 grams. That might not sound like a lot, but at around $20 an ounce it contributes more to the cost of solar than it does to the other industrial products that use silver. For example, a laptop only contains 750 milligrams to 1.25 grams of silver while a cell phone contains just 200-300 milligrams of silver, so silver is a tiny fraction of the cost of those devices.

Overall, the solar industry uses about 5% of the world's annual silver supply, or an estimated 52.4 million ounces. However, as demand for solar increases, especially in China, the demand for silver used in solar could double. Because of this it is estimated that by next year the solar industry will use 100 million ounces of silver.

Because of the volatility in the price of solar, panel makers are working on using less of it on each panel. Still, the overall increase in demand for new solar panels is what's driving the demand silver used by the solar industry. This increased demand for silver could have a real impact on the solar marketplace in the years to come as solar could push up the price of silver. So, should silver prices surge it could have an impact on the production costs of solar panels, which would then impact the economics of the solar industry.

Final thoughts

Silver is a precious metal to the solar industry. Because of this any future spike in the price of silver could hold back the growth of the industry. It's a trend to keep an eye on as surging silver prices could dim the prospects of the solar industry in the future because it's becoming such a large consumer of the precious metal.

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