Yingli Green Energy Holding Co. shares led the solar sector higher on Monday after the company forecast higher shipments this year and reported positive news about its polysilicon supplies.

Shares of the Baoding, China-based solar-power product maker rose $2.89, or 13.7 percent, to $23.97 in morning trading. The company also said Monday that it has started making thinner wafers that require less of the expensive polysilicon component, and that it has secured 70 percent of the polysilicon it will need in 2008.

However, Oppenheimer & Co. analyst Adam Hinckley said in a note Monday that the company's outlook for higher production in 2008 and its polysilicon news was "nothing to write home about." Hinckley indicated that high polysilicon costs may nonetheless pressure profit margins through the first half of the year and that its stock is "still rather expensive."

Elsewhere in the sector, Solarfun Power Holdings Co. rose $1.57, or 9.4 percent, to $18.28; Canadian Solar Inc. rose $1.72, or 9.1 percent, to $20.65; China Sunergy Co. rose 80 cents, or 8.7 percent, to $10.05; and JA Solar Holdings Co. rose $3.49, or 6.6 percent, to $56.38.

Shares of Evergreen Solar Inc. bucked the sector trend, falling 39 cents, or 3.2 percent, to $11.82 in morning trading. The company reported a stock offering worth up to $266.8 million on Monday to fund the start-up of a new facility in Massachusetts.

However, some investors took note of a cautious sentiment expressed by Goldman Sachs analyst Michael Molnar on Sunday, who reiterated a "Neutral" rating on its stock, citing uncertainty about its EverQ joint venture.

EverQ is based in Germany and partly owned by Evergreen, Renewable Energy Corp. and Q-Cells AG. The companies plan for the start-up to produce solar products like wafers, cells and panels using Evergreen's proprietary "ribbon-cutting" technology. The companies say the method is more efficient and creates more-efficient cells than traditional means of slicing polysilicon.

Molnar said it is hard to gauge whether rewards of the venture will outweigh the risks of expansion problems, high costs, potentially lower prices for solar products and competing technologies. The analyst also said there has been "noise" regarding the uncertainty of EverQ's initial public offering and the ramp-up of production at Evergreen's facilities outside of the venture.

On the other hand, Calyon Securities analyst Kelly Dougherty reiterated a "Buy" rating on the stock in a note Monday, saying its stock offering was expected but necessary and that the company is on track to provide strong earnings growth.