An inverter is an electrical device that converts direct current to alternating current. Inverters are used in PV systemsto change the DC array output to AC at a constant voltage and frequency. Also, the output power of a wind turbine may be AC or DC, depending on the type of generator, and. Figure 6illustrates inverter output waveforms after DC-to-AC conversion. Square waves are non-sinusoidal and are the easiest for an inverter to produce. Square waves can. Modern inverters use solid-state components and quality transformers and can exceed 95% peak power efficiency. Efficiency is calculated as the ratio of power-out to power.