A power supply system for a residential or a commercial unit is disclosed. The system comprises an AC power source from a power grid, a DC power source from one or a plurality of remote alternative power sources and another DC power source from one or a plurality of local alternative power sources. The generated DC power from the remote sources is delivered to the unit using a dedicated DC power distribution unit. The alternative power sources either locally or remotely located to residential or the commercial unit may comprise one or a plurality of solar systems. The system may also comprise one or a plurality of wind turbines. There are two groups of electrical appliances from the unit connected to the system. The first group receives the AC power only and the second group receives the AC and/or the DC powers. A power management device for the unit selects the power supply sources to minimize the power consumption from the AC power grid.