In 2013, the solar industry turned a corner it will never have to face again. Power generated from the sun is now competitive with the grid in locations around the world, and as costs come down and grid costs go up the demand for solar power will only increase. 

SolarCity (NASDAQ:SCTY) and SunPower (NASDAQ:SPWR) saw these benefits in the U.S., where solar leases can now be offered to customers with $0 down and a lower cost than power from the grid. There's also emerging markets like Chile, where First Solar (NASDAQ:FSLR) has a strong pipeline and SunPower is building the world's largest unsubsidized solar project to sell power straight into the grid. 

Erin Miller sat down with solar analyst Travis Hoium to see how these companies have improved in the past year and if the positive trends are sustainable long-term. 

Erin Miller has no position in any stocks mentioned. Fool contributor Travis Hoium manages an account that owns shares of SunPower and personally owns shares and has the following options: long January 2015 $5 calls on SunPower, long January 2015 $7 calls on SunPower, long January 2015 $15 calls on SunPower, long January 2015 $25 calls on SunPower, and long January 2015 $40 calls on SunPower. The Motley Fool recommends SolarCity. The Motley Fool owns shares of SolarCity. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.