Black-start capability is the ability of a power-generating unit or station to restart and return to operation after a total or partial system shutdown without relying on the external electrical transmission network.

Elering will begin procuring the capability because, under the current arrangements, re-energizing the power system takes too long as the existing grid relies on a limited number of facilities with restoration capability, said Kalle Kilk.

Under the new approach, the company plans to establish black-start service capacity close to centers of consumption.

"This will make it possible to begin restoring the power system simultaneously in several regions and ensure autonomous electricity supply in areas unaffected by the outage," Kilk said.

The exact cost of the distributed black-start service will become clear during the procurement process. The volume of the currently procured island-mode capability service will be reduced by the amount covered by the new distributed black-start service and Elering estimates that, over the longer term, costs will remain in roughly the same range.

Erkki Sapp, a member of Elering's management board, said the new service will reduce or replace the currently procured island-mode capability service, which now costs €60 million per year. However, that cost is rising because of increasing expenses associated with maintaining old power plants.

A public consultation on the concept for the new service, during which all market participants can provide feedback, began on April 20. The consultation will run through May 19, after which Elering will review the feedback and submit the principles to the Competition Authority for approval.

According to Kilk, changes in the security and energy situation have made it necessary to strengthen the power system's restoration capability.

"The experience of recent years shows that we must be prepared even for the most critical scenarios. Distributed black-start capability will allow us to restore the power system significantly faster and ensure security of supply even under difficult circumstances," Kilk said.

Elering added in a press release that recent years have shown that cross-border connections with neighboring countries may be vulnerable both to attacks and to accidents. The widespread power outage in Spain and Portugal in the spring of 2025 confirmed that even reliable systems can fail completely. In such a situation, the ability to restore electricity supply quickly and independently is critically important, the company said.

Estonia's electricity system is part of the synchronous area of continental Europe and ensuring its stability is becoming increasingly complex because of the growing share of renewable energy, Elering said. The company added that the new service will help ensure the system remains reliable even when there is less dispatchable generating capacity and electricity production depends more heavily on weather conditions.

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