A suitable size of photovoltaic system, using battery and solar backup to optimize their own consumption, to meet the needs of customers, this system will ensure the safety of all household appliances, but this system requires high efficiency The power of Xtender XTM pure sine wave inverter is at least equal to that of grid inverter, and meets the power demand of household appliances. The internal control system of the system optimizes the self consumption to ensure the energy supply in case of power failure of public power grid.