I've inherited 4 custom built solar panels. These are not consumer grade panels but industrial sized. They produce 680 volts DC at 3.8 amps. The voltage selection was probably selected to minimize the amperage and minimize current loss from transmission. That said, I would like to put these panels to work. I want them to produce as much 240, single phase power as possible. The intended use is to be off grid. The largest off the shelf charge controller I can find is the Xantrex 80 (amp)-600 (volt) XW. The voltage from the panels exceed this and I'm not finding a buck converter that will bring the voltage down to 550 or less. I am not an electrical engineer so please be explicit. I did install a grid tied system so I'm not totally clueless. :-)
What are my options?