Chinese solar companies will be "entirely blocked" from the United States market if that nation's government imposes new duties on solar cell products made in the Chinese mainland and Taiwan, experts have warned.

"It will keep all the Chinese companies out of the US market if new duties are imposed, in addition to the already unfair trade environment," said Sun Guangbin, secretary-general for solar energy and photovoltaic products at the China Chamber of Commerce of Machinery and Electronic Products.

The US solar panel producer SolarWorld Industries America Inc petitioned the Department of Commerce and the US International Trade Commission before the end of last month, requesting that the agencies launch anti-dumping and anti-subsidy investigations against crystalline silicon photovoltaic products made in the mainland and Taiwan.

SolarWorld said the petition was meant to "close a loophole in trade remedies issued a year ago".

Based on a final US ruling in 2012, anti-subsidy and anti-dumping duties were applied to panels using solar cells made in the mainland. As a result, many companies tried to avoid the duties by assembling panels from cells produced elsewhere, especially Taiwan.

According to Sun, about 70 percent of the companies that export to the US market are now using Taiwan-manufactured solar cells.

"The previous ruling was not based on the facts but on the US demand to protect local companies. I do not think it clever to continue the mistake by keeping blocking competition from China with even harsher charges. "US companies have problems with cost control and financial management, and they have to sort that out," he said.

Solar cell manufacturing in Taiwan is more integrated and focused, with four major players, said Ren Haoning, an energy analyst with China Investment Consulting. "Thus, the price is relatively low. And it is natural for mainland module manufacturers to purchase Taiwan-made cells," he added.

While SolarWorld said it was acting on behalf of the domestic industry as a whole, the US Solar Energy Industries Association rejected that claim, according to an online report by PV Magazine.

SEIA President Rhone Resch said the organization opposed the escalation of the US-China solar trade conflict, saying that more litigation was the wrong approach and a blunt instrument incapable of resolving the complex competitiveness issues that exist between the US and Chinese solar industries.

After going through trade disputes in the US and European Union markets, Chinese solar companies seem more prepared this time.

"The market always needs products with a good performance-to-price ratio. And most importantly, after going through the toughest conditions in the past two years, many of the survivors are returning to profitability," said Tony Liu, who manages a midsized original equipment manufacturer in Shanghai that focuses on solar panels.

Chinese solar exports to the US have fallen significantly since late 2012, when Washington approved anti-dumping and anti-subsidy tariffs on solar modules made of mainland-produced solar cells.

More than 100 Chinese companies have borne duties of about 31 percent since that ruling. Some pay duties exceeding 250 percent.

Shipments to what was once the Chinese industry's second-largest export destination have fallen in half to about 10 percent. They may fall even further if new tariffs are imposed, analysts said.

Chinese solar manufacturers are actively diversifying away from the US and EU markets to Japan, India and emerging economies such as South Africa.

And as China promotes renewable energy to combat air pollution and continuously raises the target for solar capacity, more companies are shifting emphasis to the domestic market.

Chen Huiqing, deputy director of the legal department of the China Chamber of Commerce of Machinery and Electronic Products, said the chamber has been holding meetings and organizing lawyers to handle the latest petition in the US.

But it's not time to make any public statement, since the US authorities haven't said whether they'll start an investigation, she added.