Energy and Buildings 47 (2012) 260–266 Contents lists available at SciVerse ScienceDirect Energy and Buildings j our na l ho me p age: www.elsevier.com/locate/enbuild Integration of plug-in hybrid electric vehicles into energy and comfort management for smart building Zhu Wang a , Lingfeng Wang a,∗ , Anastasios I. Dounis b , Rui Yang a a Department of Electrical Engineering and Computer Science, University of Toledo, 2801 W. Bancroft St., Toledo, OH 43606, USA b Department of Automation, Technological Educational Institute of Piraeus, 250 P. Ralli & Thivon Str., Egaleo 122 44, Greece a r t i c l e i n f o Article history: Received 24 May 2011 Received in revised form 5 November 2011 Accepted 29 November 2011 Keywords: Smart buildings Renewable energy Plug-in hybrid electric vehicle Interruptible load Heuristic optimization a b s t r a c t The smart building and plug-in hybrid electric vehicle (PHEV) are two promising technologies. The integration of these two emerging technologies holds great promises in improving the power supply reliability and the flexibility of building energy and comfort management. The overall control goal of the smart building is to maximize the customer comfort with minimum power consumption. In this study, multi-agent technology coupled with particle swarm optimization (PSO) is proposed to address the con- trol challenge. The proper aggregation of a number of PHEVs turns out to be able to provide both capacity and energy to make the building more economical and more reliable by impacting the building energy flow. Case studies and simulation results are presented and discussed in the paper. © 2011 Elsevier B.V. All rights reserved. 1. Introduction With the development of intelligent technologies, it is safe to say that smart building is becoming more attractive as well as more viable in the current and next-generation building indus- try. Generally speaking, smart buildings are expected to address both intelligence and sustainability issues by utilizing computer and intelligent technologies to achieve the optimal combinations of overall comfort level and energy consumption. They also uti- lize renewable energy resources to reduce the impact on natural environment [1,2]. In order to accomplish this task, a reliable, responsive, and flexible building control system needs to be devel- oped. The primary goal of the building control system is to maximize the overall comfort level while minimizing the total energy consumption. Usually, three basic factors – thermal com- fort, visual comfort and indoor air quality – determine quality of living in a building environment. Temperature, illumination level and CO 2 concentration are three main indexes for the thermal comfort, visual comfort and air quality, respectively. The auxil- iary heating/cooling system, the electrical lighting system and the ventilation system can be employed as actuators to control the physical environment of buildings [3]. Moreover, unlike the tradi- tional buildings, various customer preferences should be seriously ∗ Corresponding author. Tel.: +1 419 530 8154; fax: +1 419 530 8146. E-mail addresses: zhu.wang2@rockets.utoledo.edu (Z. Wang), Lingfeng.Wang@utoledo.edu (L. Wang), aidounis@otenet.gr (A.I. Dounis), rui.yang2@rockets.utoledo.edu (R. Yang). taken into account when designing a control system for the smart building. Much effort has been made in this research area till date. For instance, predictive control, fuzzy control and improved PID control have been used to manage the indoor environment and energy usage [4–7], and our earlier work [8–10] has discussed some case studies of energy and comfort management in various building environments. The IEEE defines those vehicles, that have at least 4 kWh of storage, can be recharged from an external energy resource and have the ability to drive 10 miles or more without consuming any gasoline, as the plug-in hybrid electric vehicles (PHEVs) [11,12]. The primary advantages of the PHEVs include cutting down the consumption of fossil fuels and reducing the emissions of green- house gases [12,13]. It is reported that fueling a PHEV will cost US $0.10/kWh of electricity while gasoline costs the equivalent of US $0.70 per gallon [14]. These claims lead the PHEVs to the world market, and make them become promising in transportation of the near future. Besides the economic and environmental benefits, large fleets of PHEVs will also have some impacts on the distribution net- work. The concept of using PHEVs as a distributed energy source, which is also known as the vehicle-to-grid (V2G), is to aggregate a number of PHEVs for connecting to the energy provider. The PHEVs have in common the batteries, which can store and release energy in different conditions. The individual PHEV has a very slight impact and it can be represented as a “noise” to the system, but the aggregation of a large number of PHEVs will markedly affect the system behaviors. These impacts are far too essential to be ignored [12,15,16]. 0378-7788/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.enbuild.2011.11.048