A new high step-up DC-DC converter for renewable energy applications is proposed in this paper. Employing an interleaved quadratic structure, two two-winding coupled inductors (CIs), and voltage multiplier cells (VMCs), the proposed converter can provide high-voltage gains, continuous input current with low ripple, reduced voltage stresses on semiconductors, common ground between input and output sides, and low numbers of components. In addition, diode-capacitor lossless clamp circuits are utilized to limit the voltage stresses of the power switches and further extend the voltage gain. The operating and steady-state analyses, design considerations, and a comparison with other previously published high step-up converters are presented. Lastly, experimental results of a 400 W prototype with 400 V output voltage are illustrated to verify the theoretical analysis and the functionality of the proposed converter.