A grid tied inverter connectable to an electricity grid, the grid tied inverter comprising a DC to DC current fed push-pull converter operable to generate a current waveform from a DC voltage source, the current waveform being substantially synchronized to the electricity grid, the push-pull converter comprising a transformer having a first side connectable to a battery and a second side connectable to the grid, wherein each of the two primary sides is connected to ground via a switching transistor; and respective voltage clamps are connected between the respective primary side of the transformer and the respective switching transistor, the voltage clamp commutating the current from the respective primary side of the transformer when the switching transistor is turned off.