Synchronous Compensator in Cabra (Córdoba): Red Eléctrica Expands 400 kV Substation in 2026

Key data

The Cabra substation (Córdoba) adds a new critical piece for the stability of the Spanish electrical network. The Resolution of 2 September 2026 from the Directorate General for Energy Policy and Mines grants Red Eléctrica de España, SAU dual authorization—prior administrative and construction—to expand the 400 kV park through the installation of a synchronous compensator of 250 MVA and its associated position.

The action is framed within the Transport Network Development Plan 2021-2026, approved by the Council of Ministers in July 2025, and responds to the need to increase the resilience of the electrical system in the face of growing renewable energy penetration, which reduces the natural inertia of the network.

What does this regulation establish?

The resolution simultaneously grants two authorizations to Red Eléctrica de España:

• Prior administrative authorization: enables the project to proceed with processing and construction.
• Administrative construction authorization: allows work to begin immediately.

The authorized technical elements are as follows:

Due to the urgent nature of the action, authorization timelines were reduced by half compared to the ordinary procedure. Furthermore, as it is located within an already operational substation, the installation is exempt from environmental impact assessment.

All consulted bodies issued favorable reports or raised no objections:

• Guadalquivir River Basin Authority
• AESA (State Aviation Safety Agency)
• Municipality of Cabra (Córdoba)
• Municipality of Lucena (Córdoba)
• Junta de Andalucía
• CNMC (National Commission for Markets and Competition)

Economic and operational impact

A synchronous compensator is a rotating machine that provides inertia and voltage support to the electrical network, two services that become scarce as conventional thermal plants are replaced by renewables. Its installation has direct operational consequences for the system:

• Greater frequency stability: the 6 seconds of inertia from the compensator dampen frequency oscillations that can cause cascading disconnections.
• Voltage support in the southern peninsula: the 400 kV park at Cabra is a key node for evacuating renewable energy generated in Andalusia.
• Reduced interruption risk: a more resilient network means less risk of outages for large industrial consumers connected to the transport network in the area.
• Accelerated processing: the 50% reduction in timelines allows the installation to enter service sooner, advancing systemic benefits.

For companies with renewable generation facilities in the southern peninsula, a more stable transport network reduces the risk of spillage restrictions and improves operational predictability.

Who does it affect?

• Red Eléctrica de España, SAU: holder of the installation and responsible for execution and operation of the synchronous compensator.
• Renewable energy generators in Andalusia: wind and photovoltaic parks connected to the southern peninsula transport network that will benefit from greater network stability.
• Large industrial consumers connected to the 400 kV network in the Cabra and Lucena area (Córdoba).
• Municipalities of Cabra and Lucena (Córdoba): territories directly involved in the processing and location of the installation.
• National electrical system operators: the improvement in inertia and voltage at the Cabra node has effects on the operation of the entire peninsular network.
• Consultancies and electrical engineering companies working on network infrastructure projects in Andalusia.

Practical example

A promoter of a 50 MW photovoltaic park connected to the 400 kV network near the Cabra substation has experienced spillage restrictions in recent months due to voltage problems in the network. With the synchronous compensator of 250 MVA entering service, the system operator will have an additional voltage support resource at that node, which can reduce the frequency and intensity of such restrictions. Additionally, the greater inertia provided (6 seconds) helps the system better tolerate sudden variations in solar generation, improving the operational predictability of the park and, therefore, its revenues in the electricity market.

For Red Eléctrica, urgent processing—with timelines reduced by half—means the installation can enter service significantly sooner than the ordinary procedure would allow, advancing the resilience reinforcement planned under the 2021-2026 Development Plan.

What should companies do now?

1. Renewable generators in Andalusia: review whether their installations are connected in the vicinity of the Cabra node (400 kV) and assess the potential impact of voltage improvement on their current spillage conditions and restrictions.
2. Large industrial consumers in the area: consult with their representative in the electricity market whether the resilience improvement at the Cabra node can translate into more stable supply conditions.
3. Electrical engineering and construction companies: identify opportunities for participation in project execution, given that authorizations have already been granted and project urgency accelerates the start of work.
4. Promoters of new projects in the area: take into account the improved capacity and stability of the Cabra node when evaluating the viability of connecting new generation installations in southern Córdoba.
5. Energy advisors and consultants: update southern peninsula network analyses incorporating the new reactive compensation and inertia capacity that this installation will provide.

Official source

Consult complete regulation at official source

Notice: This article is for informational purposes only and does not constitute legal advice. For specific decisions, consult a qualified professional. Source: https://www.boe.es/diario_boe/txt.php?id=BOE-A-2026-19315