DuPont sues Heraeus and SolarWorld over PV paste

21 Jun 2012

Chemicals giant files complaint in Oregon court accusing companies of infringing patent awarded earlier this year.

Who's shooting at SolarWorld?

DuPont, the chemicals company that supplies a huge proportion of the conductive paste used in solar cells, has launched a patent infringement lawsuit against PV cell and module maker SolarWorld and the materials provider Heraeus.

In an action filed with the US District Court for Oregon in Portland, DuPont says that Heraeus has infringed US patent 8,158,504 with its sales of front-side silver photovoltaic pastes to SolarWorld.

DuPont was granted the ‘504 patent in April this year. Entitled “Conductive compositions and processes for use in the manufacture of semiconductor devices--organic medium components”, it covers specific combinations of organic and inorganic materials for conductive pastes with improved electrical performance – designed to enable cells to convert sunlight into electricity more effectively.

The patent, originally filed back in 2009, was corrected as recently as last week, says DuPont in its court filing.

The company is seeking an injunction against Heraeus selling the silver paste, together with damages to compensate for the alleged infringement and an award equivalent to the profits that DuPont believes it has lost out on. Its legal representatives are seeking a jury trial.

Last year, DuPont also sued Germany-based Heraeus over conductive pastes in its home state of Delaware, although that pending case relates to a different patent.

Wider trade dispute
SolarWorld, which is headquartered in Germany but runs its US operations out of Portland, Oregon, has been extremely vocal in recent months, leading a successful call for the US to slap anti-dumping and countervailing duties on imports of low-cost Chinese PV modules via its self-styled “Coalition for American Solar Manufacturing” (CASM).

Analysts have since cast doubt on the likely effectiveness of those import duties, suggesting that the Chinese companies affected may be able to side-step them by re-routing their cell manufacturing via other countries not covered by the action, including Taiwan.

But SolarWorld and the CASM have responded to that by claiming that a final decision by the US Department of Commerce due in October could determine that PV modules assembled in China from cells manufactured in Taiwan, Canada or elsewhere will still be subject to the import duties.

Free trade
As a key materials supplier to a number of cell and module manufacturers, DuPont has allied itself with the Global Solar Council (GSC), described as a “CEO-level industry coalition” with the aim of expanding the global deployment of solar energy.

Other major players to have joined include leading thin-film panel maker First Solar, number-one solar equipment vendor Applied Materials and China’s Suntech Power – the world’s largest manufacturer of crystalline silicon PV cells and modules, and one of the companies that was the subject of the original SolarWorld trade complaint.

Although the members of the GSC deny that the group was set up in response to the anti-dumping claims made by SolarWorld, it has issued a call to all governments to uphold free trade in the PV market.

In a statement issued last month, shortly before the US Department of Commerce’s preliminary findings in the Chinese anti-dumping case, the GSC said:

“The growth of solar PV is facing threats from calls for restrictive trade measures that hinder access to markets rather than provide it. For solar to reach its potential as quickly and cost-effectively as possible – thereby providing the maximum economic and environmental benefit – global markets must remain open to fairly traded products. Closing markets will only serve to raise prices, slow the adoption of solar, and fragment the industry, leaving it unable to compete on a global level.”

At the time of writing, neither SolarWorld or Heraeus had yet responded to the latest DuPont lawsuit, although after the Delaware case was initiated last September, Andy London, the global manager for Heraeus’ photovoltaic business unit, said:

“We respect the intellectual property rights of others and carefully monitor industry developments to ensure full compliance and are therefore confident we do not infringe any valid patents.”