Otero Solar Park (431 MW, Segovia): keys to the favorable EIA for the renewable sector

Key data

Iberenova Promociones SAU manages to unlock the largest solar park in the province of Segovia: 431.644 MW over 923 hectares, with underground 400 kV evacuation to the Abades substation. The Resolution of May 29, 2026 from the Directorate General for Quality and Environmental Assessment formulates the favorable environmental impact statement (EIA), published in the BOE on June 20, 2026.

The path has not been easy: in 2021 there was an unfavorable EIA on a similar project of 505 MW. The current project is a reduced and adapted version that eliminated the most conflictive sectors, cutting capacity by more than 73 MW and the surface area to fit within acceptable environmental thresholds.

What does this regulation establish?

The resolution formulates the favorable EIA of the photovoltaic solar park "Otero", which enables the promoter to continue with the following administrative phases of the project (substantive authorization, municipal licenses, etc.). Without a favorable EIA, the project cannot move forward.

The key technical and environmental elements are:

The complexity of the proceedings has been especially high: the impact on steppe birds such as the montagu's harrier and the great bustard required multiple information extensions and additional field studies before being able to issue a favorable resolution. The selected alternative affects areas of high sensitivity for birds across virtually its entire surface, which has directly conditioned the content of the EIA with specific compensatory measures.

Economic and operational impact

For Iberenova Promociones SAU, the favorable EIA means unlocking a large-scale investment in solar energy. A 431 MW park represents one of the largest photovoltaic installations in Castilla y León.

For the renewable sector in general, this resolution sends clear signals about the operational and temporal cost of projects in sensitive areas:

• Extended processing time: the process has required multiple rounds of additional information and field studies, significantly extending the timeline compared to projects in areas of lower sensitivity.
• Power reduction as a strategy: moving from 505 MW (unfavorable EIA, 2021) to 431.644 MW (favorable EIA, 2026) demonstrates that adapting the project — eliminating conflictive sectors — is the way to overcome environmental assessment in environments with steppe birds.
• Permanent operational conditions: compensatory measures for fauna and Natura 2000 areas imply additional costs for monitoring, environmental surveillance, and possible restrictions in construction and operation phases.
• Underground infrastructure: evacuation via underground 400 kV line to the Abades substation has a higher cost than conventional overhead line, but was a necessary condition for the environmental viability of the project.

Who does it affect?

• Iberenova Promociones SAU: direct promoter, which can now advance in the substantive authorizations of the project.
• Affected municipalities in Segovia: the town councils in the implementation area must process licenses and manage territorial impact.
• Solar park promoters in cereal steppe areas: any company with projects in areas with montagu's harrier, great bustard, or other steppe birds should anticipate longer processes and more demanding conditions.
• Engineering and environmental consulting companies: the complexity of the proceedings reinforces the need for exhaustive field studies from the beginning of the project.
• Investors in renewables in Castilla y León: the resolution establishes a precedent on what type of adaptations allow overcoming a previous unfavorable EIA.
• Network operators and electrical infrastructure managers: the connection to the Abades substation at 400 kV affects network planning in the area.

Practical example

A renewable energy promoter has a 500 MW solar project in a cereal area of Segovia with confirmed presence of great bustard and montagu's harrier. Based on the Otero case, the most likely scenario is:

• The initial EIA may result in unfavorable if the project does not eliminate the sectors of greatest faunal sensitivity.
• To obtain a favorable EIA, the company must reduce capacity and area, eliminating sectors that overlap with breeding and ranging areas of steppe birds — in the Otero case, the reduction was from 505 MW to 431.644 MW (more than 73 MW eliminated).
• The process will require multiple additional field studies and information extensions, which can extend the proceedings several years.
• Evacuation must be planned as an underground line to minimize impact on birds.
• Once the favorable EIA is obtained, the project will be conditioned to specific compensatory measures for fauna and Natura 2000 during the entire useful life of the installation.

What should companies do now?

1. Review projects in portfolio with presence of steppe birds: identify which installations are located in areas with montagu's harrier, great bustard, or other species of high sensitivity and anticipate the need for additional field studies.
2. Analyze the power reduction strategy: if a project faces an unfavorable EIA or risk of it, evaluate the elimination of conflictive sectors as a way to obtain environmental approval, following the Otero model.
3. Plan underground evacuation infrastructure: in areas of high faunal sensitivity, budget from the start the underground option for the evacuation line, as it may be a sine qua non condition for the favorable EIA.
4. Incorporate compensatory measures in the business plan: conditions for fauna and Natura 2000 areas generate recurring operational costs (monitoring, environmental surveillance) that must be reflected in the project's financial model.
5. Consult the complete resolution in the BOE: the specific conditions imposed in the EIA of the Otero park are direct reference for similar projects in the same geographic area.

Official source

Consult complete regulation in official source

Notice: This article is merely informative in nature 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-2026-13448