In most nonlinear systems, not all the states are available for measurement. In such instances, an observer is utilized to estimate the unavailable states. Designing observers for nonlinear systems has received widespread attention owing to its utmost significance and intensive mathematical computations generally, an observer is used to calculate approximately the mechanical quantities from the identified electrical variables in an energy harvesting system. In the past, several estimations remained a challenge because of the rigorous computational techniques involved. In this work, we present a means of designing an observer by using the algebraic Ricatti equation.