Abstract:A scheme to build a small stand-alone solar power systems is introduced, which allows the user to generate electricity using photovoltaic array maximum power point tracking(MPPT) and through boost circuit and inverter to output alternating AC electrical energy, to supply the user's normal power electric demand. At the same time, some of the energy is stored in the battery, which could supply the user energy when it is in lack of light. The system has the advantages of simple structure, low cost, small volume and high feasibility, and it has very high popularization value.