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. :-)
240V from a decent H bridge needs a 350V DC supply roughly and I would think about making 350V DC (from the 680 volts) with another H bridge driver circuit dedicated to converting 680 volts DC to 350 volts DC using a transformer, rectifer and smoothing capacitor.
I'm chickening out a bit here because, I feel, using a H bridge to convert straight to 240V AC may be too big of a step but, others may offer advice to the contrary and I will look forward to their suggestions.