 In light of the Invesco Solar Exchange-Traded Fund TAN retreating close to 30 from its January high, three solar companies that have good financial strength and solid Piotroski F-scores as of Thursday are First Solar Inc. NASDAQ:FSLR, Shoals Technologies Group Inc. NASDAQ:SHLS and Enphase Energy Inc. NASDAQ:ENPH according to the All-in-One Screener, a Premium feature of GuruFocus. 