The decision to remove the second auction from the Single Day-ahead Coupling (SDAC) process, effective from 29 January 2025, reflects the evaluation of its performance and the evolving dynamics of the electricity market. The second auction was initially introduced to allow market participants to correct their bids in case of errors that could lead to extreme prices. However, it has only been triggered a few times (eight times in total during 2022 and 2023) and, notably, not due to errors made by market participants but rather as a result of severe market conditions, such as high demand or high renewable energy sources (RES) infeed.
Despite its original purpose, the second auction sometimes worsened the market results, as the post-auction outcomes were often less favorable than those derived from the first auction. This undermined the intended benefits of having an additional round for error correction. Additionally, the introduction of 15-minute resolution on the day-ahead market increases the complexity of order books and the time required for calculation, further contributing to the decision to remove the second auction.
The removal of the second auction is expected to streamline the process, as the benefits of correcting errors in bidding through a second auction were not realized in practice. This change is part of a broader effort to improve efficiency in the SDAC mechanism.
