This work is a research related to optimum design and selection of storage type electric water heaters were analyzed for energy conservation. It is concluded that a dual tank electric water heater provides more hot water and reduces energy consumption where as the upper part of the tank has 25% of the total volume and 75% of the total power rating. Some control systems were designed and studies were conducted on a variety of control systems in order to ensure energy. The results were compared with each other and the optimal control system were determined for energy saving. To evaluate single tank and dual tank electric water heaters transient energy balance equations have been derived. The differential equations with initial conditions solved using MATLAB and SIMULINK programs. Some assumption made and thermodynamic properties received to use the evaluate differential equations.