Anti-dumping duties are intended to offset the effect of below-market prices, while countervailing duties address subsidies or other government support such as tax breaks to manufacturers.

In 2013, after months of reprisals on punitive levies on solar products, China and the EU settled on a minimum price of 0.56 euros (63 cents) per watt and an annual import quota of 7 gigawatts. The accord expires at the end of this year.

The conditions are intended to protect European manufacturers that cannot make key equipment at the same price as Chinese producers that receive government subsidies.

The agreement can be extended, EU ProSun said, and it has announced plans to apply for such an extension.

Yang Liyou, general manager and chief engineer of Jineng Clean Energy Technology Ltd, an energy giant in China, said that Chinese solar companies must innovate and start buying more equipment and implementing new technologies that are needed long-term for solar companies to compete in the market.

"Chinese solar companies should end their cut-throat competition and stop prices from plummeting," he said. "More effort and money should be put into new technologies instead."