We are adding a number of alternative energy stocks to our short interest coverage this week. As crude oil prices continue to fall the impact of the lower prices on alt energy companies is beginning to be felt. This is especially true for ethanol and clean diesel providers.

Among the solar stocks, all but one saw a drop in short interest during the two-week period to November 28, and even the one that experienced a rise only saw an increase of less than 1%.

First Solar Inc. (NASDAQ: FSLR) saw short interest decline by 0.5% to 8.45 million shares, which represents 11.5% of the company’s float, and days to cover remained at four. In the two-week short interest period to November 28, shares rose about 2.6%, but they remain down nearly 19% year-to-date through Tuesday’s close at $45.06. The stock’s 52-week range is $42.68 to $74.84.

SunEdison Inc. (NYSE: SUNE) showed an increase of 0.2% in short interest to 70.7 million shares. About 26.3% of the company’s stock was short, and days to cover fell to four. In the latest two-week short interest reporting period, shares rose nearly 29%, and they are up nearly 51% year-to-date through Tuesday night’s close. The stock closed at $20.03, in a 52-week range of $11.11 to $24.35.

SunPower Corp. (NASDAQ: SPWR) short interest fell to 10.3 million shares, or 19.7% of the company’s float. In the two-week short interest period to November 28, shares rose about 0.3% but are down about 19% year-to-date, after closing at $24.45 on Tuesday. The stock’s 52-week range is $23.19 to $42.07. Days to cover fell to three.

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SolarCity Corp. (NASDAQ: SCTY) saw a short interest slip by 6.4% to 17.38 million shares, or 30.8% of the company’s total float. Days to cover rose to eight. In the two-week short interest period, shares rose about 8%, but they are down about 10% year-to-date through Tuesday night’s close. The stock’s 52-week range is $45.79 to $88.35, and shares closed at $51.64.

Canadian Solar Inc. (NASDAQ: CSIQ) has seen a drop of 15.3% in short interest in the two-week period. Some 10.9% of the stock, 4.5 million shares, were short, but days to cover is just one. The company’s shares fell more than 5.5% over the two weeks and are down about 20% year-to-date. Shares closed Tuesday night at $24.15, in a 52-week range of $21.38 to $44.50.

FuelCell Energy Inc. (NASDAQ: FCEL) had a drop of 0.2% in short interest during the two-week period. About 14.4% of the company’s stock, or 33.32 million shares, was short and days to cover is 11. In the two-week short interest period, the shares dropped about 9.7%, but they remain about 19% higher year-to-date. The stock closed at $1.72 on Tuesday, in a 52-week range of $1.28 to $4.74.

Plug Power Inc. (NASDAQ: PLUG) saw short interest rise by 3.8% to 36.55 million shares. Days to cover is seven, and nearly 22% of the company’s shares were short. In two weeks to November 28, the stock’s share price fell nearly 6%, but shares are up for the year to date by a whopping 109%. The stock’s 52-week range is $1.55 to $11.72, and shares closed Tuesday at $3.28.

Clean Energy Fuels Corp. (NASDAQ: CLNE) saw a drop of 4.6% in short interest to 16.32 million shares. About 23.6% of the company’s shares were short and days to cover is 13. Shares fell more than 10% in the two-week period to and are down 62% for the year to date. Shares closed at $5.06 on Tuesday, in a 52-week range of $4.62 to $13.69.

Pacific Ethanol Inc. (NASDAQ: PEIX) saw short interest rise by 9.6% in the two-week period to 4.39 million shares, or about 19.3% of the company’s float. Days to cover is three. The stock price fell nearly 14% in the two weeks to November 28, and shares closed at $11.62 on Tuesday, in a 52-week range of $3.74 to $23.97. Year to date, though, Pacific Ethanol’s stock price is up about 120%.

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