NEW YORK (TheStreet) -- Shares of Vivint Solar (VSLR - Get Report) were gaining 19% to $10.15 on heavy trading volume Thursday after the solar power company beat analysts' estimates for earnings in the fourth quarter.

Vivint Solar reported a loss of 36 cents a share for the fourth quarter, above analysts' estimates of a loss of 37 cents a share. Revenue grew 248.2% year over year to $6.86 million for the fourth quarter, compared to analysts' estimates of $6.01 million.

The company said it installed 50 MW worth of solar systems in the fourth quarter, a 191% increase from the year-ago quarter.

Vivint Solar expects to report revenue of $8 million to $8.5 million for the first quarter, below analysts' estimates of $8.7 million for the quarter.

The company expects to install 40 MW to 42 MW of solar systems in the first quarter.

About 2.1 million of Vivint Solar were traded by 10:50 a.m. Thursday, above its trading average of about 616,000 shares a day.

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