Recent years have seen the popularization of model based development (MBD) using models based on block diagrams. In many mechatronics systems, including automobile engine control and the brake control, a closed loop control is used to manage controls based on feedback data from control target objects. In order to develop a closed loop control using model base, a plant model that simulates the behavior of the control target plant is needed. This control model and the plant model are used throughout all the model based development processes. This paper discusses case examples in which these model based development technologies are applied to energy system developments that combine inverters and converters. We constructed a model house called “Smart Cell” as a place to demonstrate the energy system. We will introduce the Yokohama Smart Community [1] the instigators of this demonstration project. This organization aims to establish technologies that can make better use of natural energy.