The solar sector is taking quite a beating today, with the Claymore/MAC Global Solar Energy Index (TAN: sentiment, chart, options) exchange-traded fund (ETF) plunging more than 9% compared to the S&P 500 Index's (SPX) loss of about 2.65%. While the slackening demand for alternative energy sources amid plummeting oil prices bears at leas some of the blame, Robert Stone, an analyst with brokerage firm Cowen, is looking toward earnings estimates and worsening credit conditions.

According to a blog posting by Eric Savits at Barron's Tech Trader Daily, Stone cut his estimates for the solar sector across the board. "Street estimates generally have Q1 revenue flat-to-up sequentially, but we see a down tick as more likely," he writes. "The main sticking point appears to be project financing, rather than the price of modules."

Drilling down on the report, the Cowen analyst offered up the following estimate cuts:

• China Sunergy (CSUN: sentiment, chart, options): 2009 to 23 cents, from 59 cents; 2010 to 84 cents, from 95 cents.
• Energy Conversion Devices (ENER: sentiment, chart, options): 2009 to $1.51, from $1.68; 2010 to $2.68, from $3.48.
• Evergreen Solar (ESLR: sentiment, chart, options): 2009 to a loss of 2 cents, from a profit of 7 cents; 2010 to 25 cents, from 29 cents.
• First Solar (FSLR: sentiment, chart, options): 2009 to $6.07, from $7.42; 2010 to $8.36, from $10.50.
• SunPower (SPWR: sentiment, chart, options): 2009 to $2.34, from $3; 2010 to $3.24, from $4.10.
• Trina Solar (TSL: sentiment, chart, options): 2009 to $1.48, from $3.64; 2010 to $2.78, from $4.98.

Looking at the sentiment backdrops for these equities reveals that there could be ample room for more analysts and investors to jump on the bearish bandwagon. Specifically, CSUN's SOIR of 0.19 indicates that calls more than quintuple puts among near-term options, and ranks just 2 percentage points shy of an annual low. Elsewhere, ESLR's SOIR of 0.40 ranks below 88% of all those taken in the past year.

At last check, all 5 of the stock's mentioned above were off by more than 8%. The lone exception is ESLR, which has found a modicum of support at the 3 level - which is home to the equity's 10-week moving average.