The high-profile case, which has been copied by producers in Europe and spawned threats of retaliation from Beijing, now largely turns on whether the U.S. International Trade Commission finds U.S. manufacturers have been "materially injured," or are threatened with material injury, by the imports.

"We feel we have a very strong injury case," Tim Brightbill, lead attorney for SolarWorld Americas (SWVG.DE) and other U.S. producers, told Reuters ahead of an ITC hearing on Wednesday to examine the case before the panel votes in early November.

"The impact on the domestic industry has just been devastating. I think we're unfortunately up to 13 companies where there has been either a shutdown or a bankruptcy or significant work layoffs due to the Chinese imports," he said.

Even some critics of the duties, like GT Advanced Technologies (GTAT.O) President Tom Gutierrez, see little chance they won't be imposed because U.S. decision makers only consider whether U.S. producers have been harmed or threatened by the imports and not the larger impact any duties might have.

"That's the fundamental flaw in the process. ... Nothing is going to change," said Gutierrez, whose company exports high-technology equipment used in the solar manufacturing process and could be hit if China does decide to retaliate.

Gutierrez predicted that "not a single U.S. job will be created" if U.S. duties are imposed, but thousands could be lost in the installation and export sector.

The U.S. Commerce Department, which has set combined preliminary duties of roughly 35 percent on most Chinese solar panels, will make a final decision on duties on October 10.

That would set the stage for the final ITC vote in early November. It is relatively rare for the ITC to reject duties but it does occur. At least four commissioners would have to change their votes from last year, when the panel voted 6-0 that there was a reasonable indication of material injury.

HIGHER DUTIES, BROADER RULING SOUGHT

U.S. producers also hope the Commerce Department will set higher duties in its final decision next week.

They were disappointed the department set preliminary countervailing duties of just 2.90 percent to 4.73 percent to offset Chinese government subsidies and anti-dumping duties of about 31 percent to offset unfairly low pricing by the main Chinese producers and exporters.

"We don't feel (the duties) adequately reflect the entire harm or the damage that's been done to the U.S. industry," said Gordon Brinser, president of SolarWorld Americas, whose German parent company is also pushing for duties in Europe.

"If you look at the pricing collapse that's occurred over the past three years, it's (much more than what was reflected in) those initial duties that were put in place," Brinser added.

SolarWorld also wants the Commerce Department to reverse a decision that excludes from U.S. duties any Chinese solar panels made from cells manufactured outside China.

The department's preliminary stance on that issue will just encourage Chinese producers to out-source their cell production off shore to escape U.S. duties, Brinser said.

A broader order and higher anti-dumping and countervailing duties would help the U.S. industry start growing again, instead of just hanging on, he said.

However, non-manufacturing segments of the U.S. solar industry fear duties could cripple U.S. demand in the long run.

"The irony of the trade case is that at precisely the time we're making progress in reducing the price of solar, SolarWorld ... is trying to increase prices," said Kevin Lapidus, senior vice president at Sun Edison, a California-based company that installs solar panels.

Rather than try to push prices higher, the U.S. solar industry needs to find ways to further reduce costs so it can be competitive with fossil fuels, Lapidus said.

SolarWorld and other U.S. manufacturers represent only about 2 to 3 percent of U.S. solar industry jobs and are jeopardizing the future for the other 97 to 98 percent, he said.

Lapidus is a spokesman for the Coalition for Affordable Solar Energy, which estimates there are some 100,000 solar industry jobs in the United States, most of which are involved in the design, engineering, sales, installation and maintenance of solar systems.

(Reporting By Doug Palmer; editing by Todd Eastham)

• A Permanent Economic Emergency