What: 15th Slovenian Conference CIGRE-CIRED

Where: Laško, Slovenia

When: 19th – 21st October 2021

After the absence of the face-to-face conferences in almost the last two years, the representatives of COMPILE coordinator’s team, University of Ljubljana, participated in the event which was held in Laško. The 15th Conference of Slovenian Electric Power Engineers CIGRE-CIRED took place between 19th and 21st October. There were two main papers related to the COMPILE prepared and presented.

The first paper, Energy Community Luče, was written in the collaboration of the University of Ljubljana (UL), Petrol and DSO Elektro Celje and presented by Mr. Gašper Artač, PhD from UL. The article introduces the first local energy community in Slovenia which is one of the main pilot sites of the COMPILE project. The paper presents results of the operation of the energy community Luče (from its establishment until today), level of community self-sufficiency in an individual period, the impact of different technologies on the level of self-sufficiency, improvement of voltage conditions in the local network, resulting in increased use of RES due to active community management and economic benefits of community members’ participation.

The second paper, Pilot tariffing of citizen energy communities – simulations and real case study Luče, prepared the same partners as the one above and it was presented by Mr. Leon Maruša from Elektro Celje. The first part of the paper addresses the relevant legislation and the process of billing under article 137 of the Legal Act on the methodology for determining the regulatory framework and network charges for the electricity distribution system. In the second part the analysis and results of real-world monthly billing for a pilot community of Luče from 1.1.2021 onward is presented, both according to article 137 and standard billing. Further on a method for determination of optimal citizen energy community using smart meter data and mathematical optimization methods is included. The last part presents the analysis for comparison of standard and pilot billing, benefits and challenges for citizen energy communities and suggestions with foreign case studies to further stimulate the creation of these communities.

The third paper, Island Operation of the Low Voltage Network Using Battery Energy Storage Systems, was led and presented by Elektro Celje, namely Mr. Miran Rošer. The article explains the operation of the 150 kW power battery energy storage system with a capacity of 333 kWh, which was installed as part of the COMPILE project near the Luče-Urtelj transformer station. With the mode of operation used in Luče, it is possible to establish a smaller island in the low-voltage network. The key idea of the island mode operation is that customers do not feel disturbances or power outages in the event of a power failure on the medium-voltage side. The example of establishing island operation with the help of a battery storage system in the Luče-Urtelj transformer station is also the first such practical example in Slovenia. The article analyses the results of island operation test measurements which show that it is possible to switch to island operation and synchronize back to the low-voltage network without disturbance for customers.

CIGRE and CIRED are the leading global communities for the collaboration and sharing of knowledge between power system experts. Slovenian CIGRE-CIRED, established in 1992, is the National Committee and local representative organisation of global CIGRE and CIRED. The conference is the largest expert gathering in the Slovenian power system sector and allows meeting the greatest experts and companies that shape the Slovenian electric system of today and tomorrow. Through technical papers participants have an opportunity to demonstrate their knowledge and experiences.