One of the greatest advancements in residential solar during the past decade is the increase in financing offerings. The first solar lease was introduced in 2007, and soon after, SolarCity (NASDAQ:SCTY.DL) rode that to national dominance. Larger players, like SunPower (NASDAQ:SPWR), began offering leases, as well. 

But loans are emerging as a viable alternative, and a new offering from Mosaic and Enphase Energy (NASDAQ:ENPH), which includes operating and maintenance for owned systems, may make loans even more attractive. Plus, SunPower recently signed a $200 million solar-loan deal with Admirals Bank to increase its offerings. 

Find out more about where residential solar has been, and where it's going, in the following slideshow.