Smart Charging of Electric Vehicle Fleets with Solar Power and Energy Storage

Electrification of the transportation sector will bring about significant reductions in greenhouse gas emissions. However, with increasing penetration of electric vehicles (EVs) and overnight charging patterns, evening surges in power demand will stress power distribution infrastructure and degrade power quality. To address this, we present a two-stage smart charging (SC) algorithm for an EV fleet and a depot equipped with solar power generation and energy storage to minimize electricity costs and negative grid effects. We use real data from an Iowa feeder model to study the result of placing the fleet at various commercial nodes. We present a fleet-operator cost analysis under a time-of-use rate plan, and a grid-operator impact analysis considering transformer overloads and voltage sensitivity changes. The proposed two-stage SC algorithm reduces operator costs by <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">${1 9. 6 \% - 4 9. 3 \%}$</tex>, and mitigates transformer overload events and voltage sensitivity changes caused by rapid charging and rule-based BESS operation.