From pv magazine Spain
Circe, a private, non-profit research center founded in 1993 by the University of Zaragoza, the government of Spain's Aragon region, and Spanish utility Endesa, has analyzed curtailment at several Spanish substations over the past nine months and has found that curtailment is unevenly distributed, with some provinces accounting for a significant share of both total curtailed energy and the volume that could not be integrated into the grid.
The average curtailment rate stands at around 3.83%, exceeding 37% in the Badajoz province. The regions of Extremadura and Castilla-La Mancha show the highest rates, while Andalusia, despite its large installed capacity, does not register similarly high levels of curtailment.
“The key question is not: What is my curtailment rate in that region? But rather: How much am I going to lose at my connection point?” a spokesperson from Circe told pv magazine. “Although curtailment is often discussed as a single issue, it can be classified into three main categories, each with different implications and levers for action.”
The first driver is grid capacity. Curtailment occurs when the network cannot accommodate all generated electricity, typically in areas with high renewable penetration and relatively low demand. Addressing this requires investment in transmission and distribution infrastructure, including line reinforcements, substations, and expanded evacuation capacity, alongside complementary measures such as battery storage, demand-side management, and improved spatial planning for new projects.
The second driver is system security. Under certain conditions—such as infrastructure outages, grid disturbances, low inertia, oscillation risks, or voltage constraints—renewable generation may be limited to maintain system stability. This type of curtailment can be mitigated through technologies such as synchronous condensers, STATCOM systems, and other grid-support solutions.
The third driver is market oversupply. Mitigation options include increasing electricity demand through electrification of industry and transport, scaling hydrogen production, shifting consumption via price signals, deploying energy storage, strengthening interconnections to export surplus generation, and enhancing market integration and flexibility.
Circe has also developed the GenerApp tool, which enables users to assess potential curtailment risk at a specific grid node based on transmission network planning models and projected trends in generation and demand.
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.