 Shares of FuelCell Energy Inc. FCEL, -10.03 sank 8.8 in afternoon trading Wednesday, to lead its fuel cell peers in losses, after a relatively tepid endorsement of the fuel cell company by KeyBanc Capital analyst Leo Mariani, who cited smaller revenue and less visibility on near-term growth compared with its peers. And while Mariani is positive on fuel cell industry for the long term, he believes it could take years before they become competitive relative to traditional energy sources. 