Slovenian DSO registers enormous interest in connecting BESS to distribution grid
Applications for 400 MW have been submitted for the connection of battery energy storage systems to the distribution grid, according to Elektro Ljubljana, one of the distribution system operators in Slovenia.
Slovenia’s distribution system operators (DSOs) are getting an increasing number of requests to connect battery storage systems directly to distribution substations. Notably, in early May, the five Slovenian DSOs fed more electricity into the transmission network than they drew from it for the first time, and for two consecutive days.
Matjaž Osvald, Executive Director of Operation and Development of the Distribution Network in DSO Elektro Ljubljana, pointed out that last summer the company observed increased investor interest in directly connecting batteries to distribution substations.
It issued installation terms for 90 MW, and requests for at least as much are waiting to be processed, he added.
Installation terms were issued for batteries with 90 MW in overall capability
However, the company estimated there could be at least 300 MW more in applications. Due to the technical limitations of existing substations, much less could be connected. Substations in the Elektro Ljubljana area are already overloaded and don’t allow additional connections of larger devices, Osvald explained.
Furthermore, upgrading or constructing new facilities is a lengthy process, he pointed out. Current delivery times for transformers alone are longer than two years, with financing also being an issue.
According to Osvald, batteries would be used to store energy from solar power plants, and three types of investors have emerged. One group wants to install batteries to provide system services for system operators on the European market or for electricity trading.
Three types of investors are submitting applications
The second and third batch aim to bring their projects to a certain stage of development and then sell them – either they would purchase land, obtain permits, and install a battery, or only buy land and obtain permits for energy storage.
Osvald expressed concern about the idea of using batteries solely to provide system services in the European market. In that case, there would be no benefits for the Slovenian distribution network, but it could create problems, he stressed.
Such use would occupy all available connection capacity in substations, which, with increasing electrification, could lead to no spare capacity for other grid users, according to Osvald.
He also pointed to the value of BESS for the distribution network in reducing peak loads and consumption.
