Due to the increasing number of Electric Vehicles (EV) entering the transportation sector, we need to take a closer look to the distribution power grid, which needs to support the increasing number of charging processes. Grid enhancement to peak load of EV charging processes is very expensive, hence an intelligent solution is preferred. This paper introduces a new concept, called the Reward Scheme, which main objective is to advertise grid-friendly charging processes in order to avoid power quality issues in the distribution grid. To achieve this, we distinguish between guaranteed and flexible power at a charging spot. Using the guaranteed power as a reference, we calculate the grid-friendliness factor of different flexible charging rates, which in turn are proposed to the grid user, e.g. the Charging Service Providers (CSP). This paper describes a simulation-driven approach to obtain the grid-friendliness factor, as well as the required communication between the CSP and the Distribution System Operator (DSO).