Generac. The EcoGen 6-kW backup automatic household generator is designed for off-grid homes. The first automatic unit to be warranted for this type of application, the propane-powered generator works with existing solar or wind systems; if power dips too low, the inverter charger signals the generator to switch on. The generator has a weatherproof enclosure and features ultra-quiet operation of 52 dBA. 888.436.3722.www.generac.com.