- Overview of Capacity Calculation Methodology (CCM) project
- Methodology and processes
- Updates and newsletter
- Upcoming Stakeholder Events
- Day-ahead (DA) and Intraday (ID) (ATCE) Capacity Calculation
- DA/ID (ATCE) CCM EPR
- Post go-live of DA/ID (ATCE)
- Intraday (ID) Flow-based Capacity Calculation
- Long-term (LT) Capacity Calculation
- Balancing timeframe (BT)
Nordic Unavailability Collection System (NUCS)
On this page, you can find relevant information for the upcoming changes to the Nordic Unavailability Collection System (NUCS) based on flow-based capacity calculation.
The NUCS business process and platform have been introduced to improve the transparency and accuracy of outage-related information in the Flow-Based (FB) Market Coupling environment. Following the go-live of Flow-Based Market Coupling in the Nordic Capacity Calculation Region (CCR), the traditional Net Transfer Capacity (NTC)-based Urgent Market Messages (UMMs) no longer reflect the real capacity impact on the system.
The NUCS process bridges this gap by publishing outage impacts calculated with flow-based parameters, ensuring that market participants receive relevant and consistent information.
The Market Participant Handbook, available for download below, provides:
- An overview of the technical foundations for calculating the flow-based impact of outages;
- Detailed guidance on the new publication formats and data access via the NUCS web interface and API;
- Information on publication frequency, sample calculations, and XML format specifications;
- Sample calculations from the NUCS process detailing the depth of information that can be expected after go-live.
These new capabilities will be rolled out gradually during the first half of 2026, with further improvements expected as the process matures.
The publication of NUCS data supports compliance with the EU Transparency Regulation (543/2013) and REMIT 2.0 (2024/1106), ensuring timely and accurate disclosure of information related to planned and unplanned outages in the Nordic power system.
Published Handbook
Publication Handbook (NUCS): Latest Update on 30 October 2025