The Value of Flexibility in the Distribution Grid

In this paper we introduce four issues that can occur in a distribution grid as an effect of an increase in the electrical load. These four issues are: Poor voltage quality and power congestion in either normal or reserve situation. We focus on power congestion in reserve situation and show how a flexibility product delivered by production or consumption devices is able to solve this type of congestion and consequently allow grid reinforcements to be postponed. Following, we present a method that is able to compare the value of postponed grid reinforcement with the required amount and duration of the flexibility product. Finally, this method is used to conduct an analysis of a Danish 10 kV grid. The analysis shows that on average, solving the first congestion issues that will occur as the load increases has a cost around Me 0.15. The method further shows that these issues alternatively can be solved by a flexibility product with an amount and a duration in the order of 100 - 200 kW and 1 - 4 hours, respectively, and an expected value of one activation per year.