The main purpose of the research presented is how to design a Independent Photo-Voltaic System under consideration of cost and lost-load probability. The system sizing is determined with data of local weather, characteristic of load operation, and the efficiency of solar cell and lead-acid battery. In the hardware, we design the energy administrator controller(energy management) and frequency converter。The former is to modulate supplied power with generation of solar cell, the residue condition of lead-acid battery and load consumption. The latter is to reduce load consumption according the load condition.