The case hinges on whether SolarCity’s cells – based on technology it acquired when it bought Silevo in 2014 – are thin-film or crystalline silicon (c-Si).

The US has imposed significant trade duties on Chinese c-Si cells and modules, but thin-film PV products made in China are exempt.

Germany’s SolarWorld, which successfully pushed for duties on Chinese solar products in the US and the European Union, argues that Silevo modules are in essence based on c-Si technology and should be subject to US duties if the cells come from China.

SolarCity,