The square wave inverter is a type of inverter which converts solar DC power to AC power. The square wave inverter is simpler in design and more efficient than a sine wave inverter. However, the square wave will not be appropriate for some loads, because the large harmonic content can cause interference. Some electromechanical devices do not work well with square wave power. If the load is reactive, there will be loss of efficiency due to reactive power loss, so the efficiency advantage of the inverter may be nullified. Resistive loads also may suffer from radiated interference due to harmonic content.
Square wave inverter – Definition, Glossary, Details – Solar Mangoadmin