From pv magazine Spain
Spain’s transmission system operator REE has alerted regulators to sudden voltage fluctuations in the mainland grid, citing abrupt schedule changes in renewable generation and the response time of plants providing dynamic voltage control.
Although the grid remains within regulatory limits, REE said the variations could cause generation or demand disconnections that undermine supply stability.
The operator has requested urgent, temporary approval from the National Commission on Markets and Competition (CNMC) to revise several operating procedures to strengthen voltage control and response capacity. The changes would affect scheduling processes, technical restrictions, secondary regulation, and complementary voltage management.
REE plans to increase the requirement for voltage control compliance to 90% and raise sampling to 60 values per period. It also intends to require scheduled plants to reserve capacity for balancing markets, limiting their exposure to intraday trading.
As a precaution while new procedures are being introduced, REE has temporarily restricted renewable power injections to prevent grid surges.
Media reports based on the letter suggested a potential risk of blackout, which REE denied on social media. “In light of the published information, we are issuing a message of reassurance,” it said. “We have not mentioned the risk of an imminent or widespread blackout. We have recently observed voltage fluctuations that should be avoided but that have not posed a risk to supply as they have been within acceptable limits.”
REE described the measures as routine and aimed at stabilizing a grid that is increasingly affected by rapid output swings from power-electronic generation. The operator cited the growing number of large renewable plants connected at transmission level, as well as smaller systems linked to distribution networks for self-consumption, which it cannot directly monitor.
It added that expanding self-consumption during periods of strong solar generation has sharply reduced net transmission demand, leaving networks underloaded and more sensitive to active power variations that affect grid voltage stability.
This content is protected by copyright and may not be reused. If you want to cooperate with us and would like to reuse some of our content, please contact: editors@pv-magazine.com.
By submitting this form you agree to pv magazine using your data for the purposes of publishing your comment.
Your personal data will only be disclosed or otherwise transmitted to third parties for the purposes of spam filtering or if this is necessary for technical maintenance of the website. Any other transfer to third parties will not take place unless this is justified on the basis of applicable data protection regulations or if pv magazine is legally obliged to do so.
You may revoke this consent at any time with effect for the future, in which case your personal data will be deleted immediately. Otherwise, your data will be deleted if pv magazine has processed your request or the purpose of data storage is fulfilled.
Further information on data privacy can be found in our Data Protection Policy.