Later this year, DuPont Microcircuit Materials (MCM) is expecting to commercially launch a new version of its Solamet brand of PV metallization pastes that are claimed to significantly reduce the silver (Ag) content. MCM plans a new product that will reduce the silver content by 10%, having accelerated development efforts that should at a later time see a 20% reduction in silver content, all designed to be near drop-in replacements for current products.
Recently at the Photon International conference in Berlin, the cost of silver metallization pastes were highlighted on numerous occasions (see chart, left, from Mark Thirsk, Linx-AEI Consulting on metallization cost sensitivity factors) as the second biggest single cost in crystalline solar cell production, after wafers. In recent months, according to a recent research note from Commerzbank analysts, Ben Lynch and Lauren Licuanan, spot prices for silver have spiked to approximately US$50/oz.
“Lower costs are critical to the future of the PV industry, and the escalating price of silver has become a key concern for our customers,” commented Peter Brenner, global marketing manager, photovoltaics – DuPont Microcircuit Materials. “DuPont is working aggressively to reduce our customers’ reliance on silver as a basic conductive material, to reduce cell and module costs today and enable a more stable cost structure in the future. DuPont ‘Solamet’ PV17A, launched at SNEC in February, already substantially reduces the amount of paste needed to produce a solar cell, and we’re continuing to put our science to work by lowering the silver content in the paste itself with this anticipated new product system.”
MCM said that the development was part of its roadmap to enable an industry goal of reaching c-Si solar cell conversion efficiencies of over 20% by 2012, while helping to the lower the cost of PV generated energy.
However, there could be a further boost to cost saving initiatives as the Commerzbank analysts noted that this week there had been a sudden fall in Ag spot prices, dropping back to approximately US$35/oz.
Although it seems to be too short a time to confirm a pricing trend, it does suggest that, potentially, the alarming price increases may have run their course. Reducing the consumption of Ag in metallization processes remains a key cost reduction driver.
Although only a few leading-edge solar cell manufacturers are fabricating cells with copper electroplating techniques as part of the migration to back contacts, the cost of silver is such that some industry observers believe the migration to copper processes is only a matter of time.