"This Backup Power Source renewable grid-tie power system is a versatile, turnkey system that is specifically designed to provide a flexible, expandable solution for backup power, grid interactive power or off-grid power for residential or business use. It provides up to 6000 Watts of continuous power that secures critical loads, including security systems, furnace fans, refrigeration, computers, sump pumps and more. System is expandable and can be stacked to provide 12,000 or 18,000 running Watts for large power needs. Grid-tie design allows unit to work both on- or off-grid and power can be sold back to a utility during peak periods. U.S.A. Requires a licensed electrician for wiring and installation if connected to a gas line, a trained professional should make final connections. Alternative Power Collection Yes, requires charge controller and wind turbine and/or solar panels, Amps 50, Automatic Switch Back Yes, Batteries qty. 8, Allows Backfeeding of Power Yes, Electrician Required Yes, Extended Run Yes, Flex Standby Yes, Hardwired Yes, Battery Type 105Ah AGM, Dimensions L x W x H in. 34 x 15.5 x 80, Rechargeable Battery Bank Yes, Run Time hrs. 48, Running Watts 6,000, Solar Power Compatible Yes, Modified Sine Wave Pure sine wave, Power Volts 120/240, Surge Watts 12,000, Works With Gas Generator Yes. Works with alternative energy sources solar, wind and hydroelectric and/or external generators Includes eight 12V, 105Ah maintenance-free batteries Includes lockable UL listed enclosure"