The skyrocketing cost of silver will force innovation in the solar industry, according to a report from Lux Research. Solar module prices have been dropping dramatically over the last two years, despite a six-fold price jump in silver since 2002.
Silver is the primary choice for metal electrodes to collect the electricity generated by sunlight in solar panels. Lux Research analyst Fatima Toor said silver started out at about $5 an ounce in 2002 and 2003 when the solar industry began to pick up. Now it’s more than $30 an ounce. “There’s going to be a need for companies to look at changing their metallization process,” Toor said.
Research and development teams around the world are already working on alternative metals. Primary contenders include copper pastes, nickel phosphide and innovative printing techniques that reduce the amount of material used.
A double-printing tool developed by Applied Materials offers the best short-term solution, Toor said. It reduces the amount of silver needed by about 30 percent.
As solar manufacturers strive to reduce the width of silicon wafers, they will become more delicate and won’t be able to endure the standard screen-printing process used now, she said. So, new printing methods will be key.
But, long-term, there are better alternatives. “Any company that can develop copper paste would be the winner,” Toor said.
Copper is the most likely replacement for silver. It’s more plentiful and affordable and is established in the semi-conductor market. “The problem with copper is that it oxidizes,” Toor said. It’s also not nearly as efficient as silver, she said. But it will likely lead the market once researchers can get it to perform.
Right now, several companies are working to reduce their silver use by coating copper conductors in silver, which keeps the copper from oxidizing.
Another possible alternative is Nickel Phosphide. It’s durable and performs well even in high temperatures. It can trim costs slightly, buts significantly improves energy yields, Toor said. GE has patented a Nichol Phosphide process.
Toor said the research is happening now and she expects innovation to begin taking over the market in two to three years. That’s when silver will see declining use in the solar industry, she said.