Market Vectors Solar Energy ETF ( KWT) -1.7% The solar energy industry has become a darling within the energy markets as sentiment towards the nuclear energy industry continues to sour. Interest in this sector has helped KWT and the Guggenheim Solar ETF ( TAN) to charge higher, recovering some of the ground lost earlier this year. Solar remains a volatile slice of the energy industry. Investors should approached funds such as KWT and TAN with caution. All prices as of 2:16 PM EST Written by Don Dion in Williamstown, Mass.