Trading period
A trading period (kauplemisperiood) is, per Elering's glossary, the time interval set out in the network code within which a market participant must maintain its balance. It is the basic time unit for imbalance settlement, day-ahead clearing and intraday matching. Estonia historically used a one-hour period; under EBGL Article 53 (Reg (EU) 2017/2195) the EU mandates 15-minute imbalance settlement, with SDAC moving to 15-minute MTU on 1 October 2025.
A trading period (kauplemisperiood) is, per Elering's glossary, the time interval set out in the network code within which a market participant is required to maintain its balance. It is the basic time unit for everything downstream — imbalance settlement, day-ahead clearing, intraday matching.
From hourly to 15 minutes
Estonia historically used a one-hour trading period, with the day starting at 00:00 and the last hour 23:00–00:00. Under EBGL Article 53 (Commission Regulation (EU) 2017/2195), the EU mandates a 15-minute imbalance-settlement period (ISP) across all Member States. Estonia has transitioned its imbalance settlement and balancing-market activations to 15-minute resolution; the SDAC day-ahead market moved to 15-minute MTU on 1 October 2025.
What the change does to economics
A finer trading period rewards faster assets. A battery that responds in seconds captures intra-quarter-hour spreads invisible at the hourly resolution. Slower assets — combined-cycle plants, heat pumps with thermal inertia — face larger relative imbalance penalties because their ramp rates are now in the same band as the settlement window. The transition has compounded the structural advantage of fast-flexibility assets.