The Nordic Transmission System Operations have decided to switch from 1 hour to 15 minutes imbalance settlement period.

The go-live date for the 15-minute imbalance settlement period (ISP) will be on Monday May 22, 2023 at 00.00 CET, at the beginning of an imbalance settlement period.

Below are listed the most relevant effects in different areas. The three first points concern all Nordic BRPs and DSOs in all countries. For the full details, go to eSett’s 15-minute project site and read our commissioning plan.

First and foremost, the 15-minute transition point (15MTP) is on Monday 22 May 2023 at 00:00 CEST. There are some limitations for all market participants in the reporting to eSett during this time. Any message that contains timeseries data and the delivery days in the message overlaps the 15MTP will be rejected. See commissioning plan slides 18, 28 and 29 for the details and examples.

The outgoing data shall primarily be available on 15-minute resolution for the delivery days after the 15MTP for all market participants. Each market party needs to subscribe to the new 15 min data packages themselves in Online Service closer to the transition point. Hourly data will be available in Online Service, Information Service and via specified data flows (see commissioning plan slide 23).

Any hourly data that is reported to eSett for the delivery days after the 15MTP shall be converted into 15-minute data. This may result in minor rounding errors, as presented in the commissioning plan slide 14. Data is always rounded to the closest watt-hour (Wh) i.e. to 6 decimals in MWh or 3 decimals in kWh.

In Denmark and Finland, also some of the meter data and reporting will transition to 15-minute resolution starting from 22 May 2023. Details of what data needs to be metered and reported in 15 min are defined by the national rules and instructions. Questions about the 15-minute metering regulations in different countries can be directed to the local TSO(s).

Commissioning plan

eSett has published a 15 min ISP commissioning plan to help the market to identify and understand the changes that are relevant for them.

For additional information, please see the information on, and on the national TSO websites:

We recommend subscribing to our newsletter to learn more about the upcoming changes in the market.


Webinar: 15 min ISP project status and testing phase

eSett arranged a webinar about the 15 min ISP project status and testing on Tuesday 10.1.2023 9:00-10:00 CET (10:00-11:00 EET). A recording of the webinar can be found below.

The webinar presentation can be found here. The Q&A part is included at the end of the presentation material in a written form.


Webinar: Commissioning Plan for 15 min Imbalance Settlement Period

eSett arranged a webinar about the Commissioning Plan for 15 min ISP on Tuesday 18.1.2022 9:00-10:00 CET (10:00-11:00 EET). A recording of the webinar can be found below.

The Commissioning Plan can be found above on this page and the material from the Q&A part of the webinar can be found here.