The first was the Trace Mirco Sine and it was UL1741 listed in 1998, then it was made as the OK4U, no UL listings and sold on eBay
The unit is on the CA list of approved vendors:
http://www.gosolarcalifornia.org/equipment/inverter.phpAnd its performance data is
http://www.gosolarcalifornia.org/equipm ... -240-S.pdfA couple of thoughts:
Having AC as the array interconnect means everything must be in conduit, current MC cabled systems do not have this requirement.
Instead of current limited DC running around the roof, there is now breaker limited 240VAC. Typical high voltage strings are in the 300-400 Volt ranges, so it would appear on large arrays this would have higher currents on the AC wiring with the need for larger wire size
NEC 690 has requirements for DC/AC disconnects, its not obvious to me where the disconnect is for this inverter.
The inverter is now subject to the panel temperatures, the test data only shows 40C operation, it will be at least double that ( probably more like triple ) in roof mounted arrays, that will hurt efficiency and life of the inverter
The claim of a array being limited by the lowest performer in series is not quite true. I have found with extensive testing what happens is yes, an array will operate at the lowest current BUT, the other panels then operate at a higher voltage to match the slighty reduced current. The VI curve of a solar panel is fairly flat meaning if the current is reduced most if not all the difference is gained by running at a slightly higher voltage.
Mating a inverter to a single panel means you have a 5-10 year device on a 40+ year panel, have fun when one of your 50 inverters dies and its in the middle of the array. Inverters on the side of the house can be easily accessed and replaced
With so many manufactures of inverters these days, its becoming increasingly harder for the manufactures to standout from the crowd and this is a feature that no one else has.
The is NO chance this will takes any sales away from current large gridtie sales, it might find a place in the people who want to be gridtie with a panel or two, but the math/payback makes no sense for this sized systems
I think this will go the way of the micro inverters before them and then what happens if the company in 3 years is no more?, with house mounted inverters, you can always swap in some other manufactures inverter, not the case with this unit and you have 20-30X more of them!