SolarCity has a new panel that trumps SunPower's best panel and now reigns champ for having the most efficient panels:
http://www.forbes.com/sites/greatspeculations/2015/10/06/should-sunpower-investors-be-concerned-as-solarcity-clinches-module-efficiency-title/
SolarCity (SCTY) Unveils Worlds Most Efficient Rooftop Panel - NASDAQ.com
they announced that a few days ago. but now just a few hours ago, Panasonic is saying that they have new panels that are even better and more efficient that SolarCity's:
Panasonic surpasses SolarCity with worlds most efficient solar panel | Computerworld
Panasonic to SolarCity: Sorry, We Have the Most Efficient Solar Panel | Greentech Media
Panasonic trumps days-old SolarCity module efficiency record | PV-Tech
http://www.forbes.com/sites/greatspeculations/2015/10/06/should-sunpower-investors-be-concerned-as-solarcity-clinches-module-efficiency-title/
SolarCity (SCTY) Unveils Worlds Most Efficient Rooftop Panel - NASDAQ.com
they announced that a few days ago. but now just a few hours ago, Panasonic is saying that they have new panels that are even better and more efficient that SolarCity's:
Panasonic surpasses SolarCity with worlds most efficient solar panel | Computerworld
Panasonic to SolarCity: Sorry, We Have the Most Efficient Solar Panel | Greentech Media
Panasonic trumps days-old SolarCity module efficiency record | PV-Tech