(SunPower story updated for Wedbush, Barclays analyst comments, and updated trading losses)SAN JOSE, Calif. ( TheStreet) -- SunPower ( SPWRA), with more than a 15% decline in share value on Friday, has reached its inflection point in respect to the larger inflection point for the solar industry. Weak 2010 guidance and consolidated gross margin deterioration were culprits in the dim investor outlook on SunPower in the immediate aftermath of its fourth-quarter earnings. Some commentators said after the disappointing 2010 outlook from Sunpower, the freefall in shares represented a short-term negative phenomenon. Yet the larger debate is really about multiples that can be justified on solar stocks increasingly framing their business with a lower-margin energy construction focus. While SunPower reported somewhat benign results of a four-month-long audit investigation into accounting mistakes made at its Phillipines plant, there was no relief rally in sight for the U.S. solar stock from the resolution to that nagging issue. All the focus coming into SunPower earnings was on the accounting resolution. Ironically, it turned out be a non-issue in the beating SunPower shares have taken as a result of the company's 2010 outlook. Analysts, for their part, were divided in their reaction to the SunPower outlook. It wouldn't be solar, or most industries for that matter, if there was not a healthy debate about what the same set of numbers represented: an opportunity to buy or the time to bail on a hard-to-justify share price story? One solar analyst noted that SunPower came in well below Street guidance, and that even more concerning is that the Street guidance did not include any modeling of SunPower's recent acquisition of European solar project developer SunRay, while SunPower's guidance did in fact include SunRay business. SunPower has forecast earnings per share of five to 35 cents in 2010, a starkly sober outlook, according to some solar analysts, for a stock that has traded as if it were a technology company. Analysts estimated earnings per share of 17 cents in the first quarter 2010 alone. SunPower said the first quarter would be a break-even quarter. "It's hard to justify a $20 stock view on SunPower. They found the root accounting problem, spent several million to fix it -- $3.6 million -- and think they have it solved. But the quality of earnings is low, and investors are likely to bin this stock with the likes of Energy Conversion Devices and Evergreen Solar," the analyst said. Being lumped with Energy Conversion Devices ( ENER) and Evergreen Solar ( ESLR), two U.S. companies fighting for survival, may be a stretch. SunPower has a pretty healthy balance sheet compared with those two embattled U.S. solar companies.