Investigating the benefit of flexibility services in distribution grids under uncertainty

The ongoing electrification in distribution networks induces congestion issues resulting in the need for network reinforcement. However, demand flexibility and intelligent utilization of grid components have the potential to defer network investments. This paper introduces a procedure for the evaluation of flexibility services in distribution grids, considering the thermal model of the substation transformer, impact of outage and cost of flexibility. A case study involving electric vehicles as the flexible load is presented, where the cost and flexibility benefit values are computed. Uncertainty in the load forecast is included in the process and an assessment of the risk level and aptitude is performed. The results show the dominating impact of disconnection in relation to ageing, meaning that allowing some levels of overloading could be more preferable than procuring flexibility in certain situations. Taking into account the uncertainty of the load, the associated cost and flexibility benefit can be assessed depending on the choice of service parameters and risk consideration, supporting decision-making for flexibility in the presence of uncertainty.