The Slovenian electricity market switched from an hourly to a 15-minute ISP with the delivery date 1 January 2021. In general, this means that the basic unit of account, as far as the market is concerned (closed contracts, operational forecasts, imbalance settlement), switches from one hour to 15 minutes. In this way, the market system will be closer to the operation of a real-time electricity system.
The transition to a 15-minute interval stems from the requirement of one of the EU codes, more precisely the Commission Regulation (EU) 2017/2195 on the establishing a guideline on electricity balancing. The similar requirements can also be found in the Clean Energy Package (CEP). The idea of the legislators was to unify the interval throughout the European market. If we ignore the countries that have already switched to a 15-minute interval, Slovenia will actually be the second country to carry out such a transition (i.e. after Greece in November). The implementation will be within the deadline set by the aforementioned regulation and all other countries have exercised the option of the possibility of the so-called derogation (postponement), which is usually approved by the domestic regulator, until 2025, mostly due to data problems at the distribution level.
The transition required a lot of preparation for the operator Borzen, as well as other market operators, as it was necessary to make changes to the applications, data flows and forecasting models. To help market members, Borzen has been publishing 15-minute test data provided by the electricity operators for quite some time now (for the periods from January 2019 onwards), as well as calculated test prices of the imbalance settlement based on the data provided by electricity transmission system operator ELES.
