Households with plug-in hybrid vehicles, or PHVs, and smart meters actively managed how, when and where they charged their cars based on electricity rates but rarely took advantage of online feedback, a University of Colorado Boulder study found. Ƶ-Boulder’s Renewable and Sustainable Energy Institute, or RASEI, today presented findings from the two-year study -- one of the only of its kind, combining both household and vehicle data in a smart-grid context.