This system uses Schneider Electric’s XW system (Schneider (think: Square D) bought Xantrex in 2009) and their new XW MPPT 80-600 Charge Controller with 21 Sanyo HIT225 solar modules for 4725 Watts of Solar. 6000 watt grid tie/battery back up inverter. 415 AH Full River Batteries. In grid tie mode this system will offset about half of the homes electric bill. When the grid goes down the system transfers (lights hardy flicker and computers stay on line during transfer) to batteries and solar, keeping all of the critical loads up and running for indefinite autonomy. These batteries will run the critical loads for about two cloudy days. A portable or stationary generator can also be tied into this system for use during long cloudy times.