After the Great East Japan Earthquake on March 11, 2011, Toyota Motor Corporation received considerable public response regarding the role of vehicles in emergencies from a large number of customers. These included comments about the usefulness of the electricity supply system in the Estima Hybrid during the long power outages caused by the earthquake. In response, Toyota decided to install this system in its other hybrid electric vehicles (HEVs) and plug-in hybrid electric vehicles (PHEVs). This system is capable of supplying power up to 1,500 watts, which means that it can be used to operate virtually every household electrical device. Since the engine starts automatically when the main battery capacity is depleted, a single vehicle can supply the daily power needs of a normal house in Japan for about four days, providing that the battery is fully charged and the fuel tank is full. When adopting the electricity supply system in its PHEVs, Toyota developed a Vehicle Power Connector (VPC) with an outdoor outlet that is capable of drawing power from the vehicle inlet (i.e., the charging inlet). This enables the vehicle to supply power directly to electrical devices, and may supply power at either a home site, or evacuation center in the event of a natural disaster. This paper describes the development of Toyota's electricity supply system.