Technical dimensioning of an energy storage fora Swedish distribution company

A grid-size energy-storage installation enables the removal of peak loads in the distribution system due to high amounts of wind production. In this paper the ability of a battery energy storage to increase the amount of wind power that can be connected to a distribution network is studied. It is found that about 40 % of overloading instances can be prevented with the storage. After this diminishing returns per unit of storage capacity occur and the overloading should instead be handled with curtailment. The extent to which the storage can minimise network losses was studied but the reduction in losses cannot compensate for the conversion losses in the storage installation.