ACER EU Energy Markets Brief
Headline
ACER approves amendments to PICASSO and MARI balancing platform implementation frameworks via Decisions 12/2026 and 13/2026
Executive Summary
ACER has approved amendments to the PICASSO and MARI cross-border electricity balancing platforms through Decisions 12/2026 and 13/2026. The decisions introduce a structured biennial harmonization process, revised prequalification requirements, and three prequalification pathway options for balancing service providers.
Bottom Line
ACER's Decisions 12/2026 and 13/2026 amend the implementation frameworks for PICASSO and MARI, establishing a biennial harmonization review cycle, three prequalification pathways, and revised requirements for switching, re-prequalification, termination, and data exchange. TSOs have six months to submit national alignment proposals, with 24 months to implement the harmonized prequalification process after national regulatory authority approval.
Key Regulatory Signals
- Biennial Harmonization Cycle Established: Under the approved decisions, TSOs are required to run stakeholder surveys every two years to identify areas where balancing service provider terms and conditions remain misaligned across EU Member States, followed by a common proposal and public consultation. Cresthaven reading: balancing service providers operating across multiple Member States face a recurring structured review cycle that may alter their participation terms on a two-year cadence.
- Three Prequalification Pathways Now Available: ACER introduced activation testing, ex-post verification, and a fast-track process as prequalification options for balancing service providers. The ex-post verification and fast-track options allow market access with services monitored during operation rather than tested upfront, subject to approval by the relevant national regulatory authority.
- Additional Harmonized Prequalification Requirements Introduced: ACER added requirements covering switching, re-prequalification, termination of prequalification, and data exchange. Some requirements remain at national level given limited experience with harmonized prequalification, with further alignment expected as TSOs accumulate operational experience.
- Simplified Access for Smaller Market Participants: ACER adapted prequalification processes that were designed around large conventional generators to facilitate entry by smaller participants capable of providing secure and reliable balancing services, with the stated objective of improving market liquidity and ensuring a level playing field.
- Implementation Timeline Set at National Level: TSOs have six months from the decisions to submit proposals to their national regulatory authority to align national terms and conditions with the new requirements. Following national approval, TSOs have 24 months to implement the harmonized prequalification process.
Regulatory Delta
No direct precedent exists for a biennial structured harmonization cycle under the PICASSO and MARI frameworks. This is a new procedural mechanism within the Electricity Balancing Regulation architecture.
The decisions move beyond the original implementation frameworks by introducing three distinct prequalification pathways and a recurring stakeholder-driven review process.
The six-month national submission deadline and 24-month implementation window apply to TSOs, with implementation following approval by their national regulatory authority.
Materiality Classification
HIGH — ACER decisions on cross-border electricity balancing platform implementation frameworks carry binding effect on TSOs and balancing service providers across EU Member States, with explicit implementation deadlines and a sector-wide structural change to prequalification processes, matching the HIGH anchor class for ACER decisions on cross-border energy market rules.
Intelligence Outlook
Monitor ACER and national regulatory authorities for TSO national alignment proposals submitted under this proceeding and for national approval decisions that trigger the 24-month implementation clock.