Assessment of EV hosting capacity in a workplace environment in different charging strategies

Abstract

The study establishes a methodology to assess electric vehicle (EV) hosting capacity in different grid points under various charging strategies in a workplace environment. The methodology is applied to an actual distribution grid in the Helsinki central area. The EV penetration rate is calculated as the number of EVs over the number of parking places in the connection point. The results indicate that in the example grid, the EV hosting capacity is not limited by grid dimensions even in the case of uncontrolled charging. For the grid utility, the possible overloading can be regulated by a power-based tariff that guides the commercial electricity customers to avoid uncontrolled morning charging and spread the EV charging load evenly throughout the working day. According to the calculation results, integration of solar PV on the rooftops of office buildings decreases annual payments, but not significantly, owing to only a few sunny months in Finland.