At this time, the closely watched fuel is battling against storms on all sides. Warm weather is constricting demand while, at the same time, industry specialists note that inventories are brimming. Winter weather may help limit this price drop. However, UNG and GAZ should continue to be monitored from the sidelines. Guggenheim Solar ETF ( TAN) The solar sector spent the great portion of 2011 trading lower as persistent macroeconomic concerns weighed heavily on investor confidence in alternative energy. While many of these daunting factors remain in play, the clouds appear to have begun to lift. Over the past week, both TAN and the Market Vectors Solar Energy ETF ( KWT) (KWT) saw a dramatic about-face. A single week of strength is not enough to confidently state that the fog has lifted on this industry. However, given the magnitude of this run up, TAN and KWT are certainly worth watching in the days ahead. Written by Don Dion in Williamstown, Mass.