Designing tariff for charging electric vehicles at home with equity in mind – The tripartite tariff
Oluwasola O. Ademulegun, Damian Flynn, Neil Hewitt
Abstract
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.