Electric Vehicle (EV) charging will add to the demand for electricity in Northern Ireland (NI) and will prompt upgrades at points on the electricity grid. The impact on the grid will depend on location with respect to existing infrastructure and the level of increasing electricity demands from low-carbon technologies like EVs. While certain network upgrades will be inevitable, being able to charge EVs at different times of the day and the aggregate amount of energy demand through EVs present electricity demand flexibility opportunities, especially in NI, where a pioneering proportion of variable renewable energy resources, mostly wind turbines, have been connected to the electricity grid. With an estimation of the aggregate energy through EVs in NI, the aggregated electricity demand flexibility opportunities are presented through different charging times such that the use of existing electricity network and renewable energy generation infrastructures are optimised, and EV users benefit from lower charging rates. Current and future EV levels of EV uptakes are used as scenarios of aggregated electricity demand, and the impact and benefits of scheduling are analysed with respect to the resources at different locations within the NI electricity supply system. The results show the specific energy per day that using EVs for all journeys in NI will require. When a storage device is to be included at a public charging site for time-of-use electricity demand, the results show at what point that makes economic sense, considering the cost of battery, available tariff, and EV usage at that point. The results also suggest the level of EV usage required and tariff differences needed at locations of the NI electricity supply system.