*Article* **Cost-Aware Design and Simulation of Electrical Energy Systems**

#### **Yukai Chen 1,\*, Sara Vinco 1, Donkyu Baek 2,\*, Stefano Quer 1, Enrico Macii 3 and Massimo Poncino 1**


Received: 21 April 2020; Accepted: 4 June 2020; Published: 8 June 2020

**Abstract:** One fundamental dimension in the design of an electrical energy system (EES) is the economic analysis of the possible design alternatives, in order to ensure not just the maximization of the energy output but also the return on the investment and the possible profits. Since the energy output and the economic figures of merit are intertwined, for an accurate analysis it is necessary to analyze these two aspects of the problem concurrently, in order to define effective energy managemen<sup>t</sup> policies. This paper achieves that objective by tracking and measuring the energy efficiency and the cost effectiveness in a single modular framework. The two aspects are modeled separately, through the definition of dedicated simulation layers governed by dedicated virtual buses that elaborate and manage the information and energy flows. Both layers are simulated concurrently within the same simulation infrastructure based on SystemC-AMS, so as to recreate at runtime the mutual influence of the two aspects, while allowing the use of different discrete time scales for the two layers. Thanks to the tight coupling provided by the single simulation engine, our method enables a quick estimation of various cost metrics (net costs, annualized costs, and profits) of any configuration of EES under design, via an informed exploration of the alternatives. To prove the effectiveness of this approach, we apply the proposed strategy to two EES case studies, we explored various managemen<sup>t</sup> strategies and the presence of different types and numbers of power sources and energy storage devices in the EES. The analysis proved to allow the identification of the optimal profitable solutions, thereby improving the standard design and simulation flow of EES.

**Keywords:** design-time optimization; cost modeling and simulation; cyber-physical system; electrical energy system; sustainable energy planning; sustainable power planning; design space exploration; SystemC-AMS
