The competition doesn't sleep: http://www.greentechmedia.com/articles/read/sungevity-and-so...

In fact they seem to be ahead. Sonnenbattery offers http://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery since 2011 in Germany.

For technical details see http://www.sonnenbattery.com/strom-energie-speicher/sonnenba...