als " ▁and ▁there ▁have ▁been ▁hundreds ▁of ▁compla ints ▁to ▁state ▁att or ne ys ▁general . ▁ ▁The ▁federal ▁government ▁is ▁investig ating ▁whether ▁solar ▁companies ▁are ▁" mask ing ▁how ▁many ▁customers ▁they ▁are ▁losing ". ▁The ▁SE C ▁is ▁involved ▁because ▁" in vest ors ▁use ▁that ▁can cellation ▁metric ▁as ▁one ▁way ▁to ▁gauge ▁the ▁companies ' ▁health ". ▁According ▁to ▁the ▁Wall ▁Street ▁Journal , ▁" To ▁generate ▁business , ▁solar ▁companies ▁have ▁long ▁re lied ▁on ▁thousands ▁of ▁sales people ▁who ▁knock ▁on ▁doors , ▁make ▁hundreds ▁of ▁cold ▁calls ▁and ▁even ▁trail ▁people ▁as ▁they ▁shop ▁at ▁ret ail ers ▁like ▁Home ▁Dep ot ▁Inc ., ▁according ▁to ▁sales people , ▁execut ives ▁and ▁home own ers ." ▁ ▁F CC ▁receiving ▁radio ▁inter ference ▁compla ints ▁ ▁Sol ar City ▁installed ▁Sol ar Edge ▁in verter ▁systems ▁with ▁a ▁type ▁of ▁DC - DC ▁converter ▁called ▁an ▁optim izer . ▁These ▁systems ▁cause ▁radio ▁inter ference ▁as ▁documented ▁in ▁April ▁ 2 0 1 6 ▁Q ST ▁magazine ▁a ▁publication ▁of ▁the ▁AR RL ▁( ▁American ▁Radio ▁Rel ay ▁League ▁). ▁ ▁Federal ▁settlement ▁for ▁alleg ations ▁of ▁False ▁Cla ims ▁Act ▁viol ations ▁In ▁September ▁ 2 0 1 7 , ▁as ▁part ▁of ▁a ▁legal ▁settlement ▁with ▁the ▁federal ▁government , ▁Sol ar City ▁agreed ▁to ▁pay ▁a ▁$ 2 9 . 5 ▁million ▁penalty ▁regarding ▁alleg ations ▁that ▁the ▁company ▁over st ated ▁the ▁cost ▁of ▁facilities ▁it ▁developed ▁and ▁submitted