This report reviews a set of electric grid ancillary services and analyzes the technical potential for residential devices to provide those services. A set of common residential devices are evaluated against six indicators of capability: flexibility, availability, fast response, reserves, reactive power, and power level. Based on these indicators of capability, three scores are developed to express the potential of a device to provide frequency response, reserves and reactive power services. These scores are additionally used to estimate how many of each device might be required, in aggregation, to provide a meaningful level of each of these three ancillary services to the grid. This report also provides a review of some existing programs and pilot efforts where residential devices are being used to provide ancillary services. Lastly, the report provides insights on a continued path to increased integration of residential devices for ancillary services provision.