Arizona's largest utility company has been at odds with the solar panel industry for years. Now, APS [Arizona Public Service, the state's largest utility] is asking the Federal Trade Commission to crack down on solar companies. But they didn't ask them directly. Six Arizona Congressmen sent letters to federal regulators asking them to investigate solar leasing companies. Reporter Evan Wyloge ... has the original letter and proves it's actually APS spearheading the effort. Arizona Public Service [is] one of the largest campaign donors for the group of lawmakers. The APS-authored, congressmen-signed letter comes as the latest in an ongoing effort to stymie third-party solar panel companies, whose business has grown tenfold over the past half-decade, presenting a challenge to the long-term business model of traditional utilities like APS. The high-profile fight between the traditional utility and newer rooftop solar panel companies is not unique to Arizona. Similar struggles have emerged in other states. On Nov. 19, Democratic Reps. Ron Barber, Ann Kirkpatrick and Kyrsten Sinema asked [regulators] in a joint letter to ... look into solar panel leasing practices. Then, on Dec. 12, Republican Reps. Trent Franks, Paul Gosar and Matt Salmon sent a similar letter to the FTC. After both letters were sent, the Arizona Corporation Commission voted late in 2014 to open a docket on consumer complaints about solar companies. Initial hearings are expected to begin this spring.