Energy Syst (2012) 3:133–151 DOI 10.1007/s12667-012-0053-1 ORIGINAL PAPER Optimized energy management for large organizations utilizing an on-site PHEV fleet, storage devices and renewable electricity generation Yogesh Dashora · J. Wesley Barnes · Rekha S. Pillai · Todd Combs · Michael Hilliard Received: 29 August 2011 / Accepted: 24 January 2012 / Published online: 8 February 2012 © Springer-Verlag 2012 Abstract This paper focuses on the daily electricity management problem for orga- nizations with a large number of employees working within a relatively small geo- graphic location. The organization manages its electric grid including limited on-site energy generation facilities, energy storage facilities, and plug-in hybrid electric ve- hicle (PHEV) charging stations installed in the parking lots. A mixed integer linear program (MILP) is modeled and implemented to assist the organization in determin- ing the temporal allocation of available resources that will minimize energy costs. We consider two cost compensation strategies for PHEV owners: (1) cost equivalent battery replacement reimbursement for utilizing vehicle to grid (V2G) services from PHEVs; (2) gasoline equivalent cost for undercharging of PHEV batteries. Our case study, based on the Oak Ridge National Laboratory (ORNL) campus, produced en- couraging results and substantiates the importance of controlled PHEV fleet charging as opposed to uncontrolled charging methods. We further established the importance of realizing V2G capabilities provided by PHEVs in terms of significantly reducing energy costs for the organization. Keywords Optimization · PHEV · Energy management · MILP 1 Introduction & background This paper focuses on large electricity customers such as universities, National Lab- oratories, and corporations where a great number of people work within a defined Y. Dashora ( ) · J.W. Barnes Graduate Program in Operations Research and Industrial Engineering, The University of Texas, Austin, USA e-mail: yogesh.dashora@gmail.com R.S. Pillai · T. Combs · M. Hilliard Oak Ridge National Laboratory, Oak Ridge, USA