Solar stocks were up nicely today and the option volume spiked in many of the names. 

The following showed up on my nightly scan for highest % change in option volume above its 10 day average: 

SOLF 576%

LDK 346%

TSL 223%

STP 197%

YGE 196%

Most of the volume came from call buying so it will be interesting to see if these bullish bets pay off.