This article is a feasibility analysis of using the batteries in plug-in hybrid electric vehicles (PHEVs) for peak shaving. The analysis focuses on energy availability of the PHEV fleet as well as the financial savings to the utilities by analyzing different charging scenarios and circuitry. The energy availability and the financial savings are heavily dependent on the location and availability of charging stations. Three charging scenarios are analyzed: charging is possible at any time; cars can only be charged overnight; and charging can be done overnight and twice during the day at the place of work for cars used for commuting. The major findings of the study are that charging only overnight will not provide sufficient energy when needed, but both other charging mechanisms can provide effective peak shaving. The charging anytime would require funding a large number of charging station, but charging overnight and at work could be accomplished with relative minor financial investments. The savings from peak shaving could be used for incentives to offset the extra cost of batteries in plug-in electric vehicles (EVs).