Designing Tariff for Charging Electric Vehicles at Home with Equity in Mind – The Tripartite Tariff

Extant electricity tariffs model an industrial age when electricity predominantly came from centralised conventional generators, and they still model the pre-pandemic years when virtually everyone shared similar work pattern of working from dawn to dusk. The extant home electricity tariffs offer off-peak electricity mainly during night hours. The tripartite tariff – a home Electric Vehicle (EV) charging tariff that offers off-peak EV charging opportunities during daytime and night hours – is presented. The objective is to assess how access to a tripartite tariff impacts an individual worker's ability to charge their EV at home using off-peak electricity and implications in cognizance of a democratised next generation energy system desirable in an heterogenous society. Using 15 user profiles that represent low-income, middle-income, and high-income earners, working at different times of the day within four successive weeks, the tripartite tariff is designed for inclusive EV charging. With a traditional tariff regime – which represents existing off-peak electricity tariffs – the low-income earners who would typically need off-peak EV charging the most tend to have the least access to it. The tripartite tariff offers inclusive EV charging opportunity at lower off-peak rates for every worker category: night-time, daytime, and mix daytime-and-nighttime workers.