Key data
| Regulation | Resolution of June 3, 2026, from the Directorate General for Quality and Environmental Assessment — Environmental impact report for the project "Mulhacén Solar Storage Module" |
|---|---|
| Publication | June 17, 2026 |
| Entry into force | June 17, 2026 |
| Affected parties | Mulhacen Solar SL (promoter), administrations of Castilla-La Mancha, municipalities of Esquivias and Numancia de la Sagra (Toledo) |
| Category | Energy / Environmental assessment |
| Year | 2026 |
| Module power | 21.56 MW (storage with lithium-ion batteries) |
| Area occupied | 1,379 m² |
| Underground evacuation length | 51.86 m |
| Applicable legal framework | Law 21/2013, on environmental assessment |
| BOE reference | BOE-A-2026-13197 |
Mulhacen Solar SL now has environmental approval to hybridize its existing photovoltaic plant with a 21.56 MW battery module located in the Toledo municipalities of Esquivias and Numancia de la Sagra. The Resolution of June 3, 2026 from the Directorate General for Quality and Environmental Assessment (published in the BOE on June 17, 2026, reference BOE-A-2026-13197) formulates the simplified environmental impact report with a favorable result, unblocking the path toward the project's final authorization.
This type of report is not a minor formality: without it, no energy project of these characteristics can obtain final authorization in Spain. Its approval confirms that the project complies with the requirements of Law 21/2013 on environmental assessment and that the promoter has fully accepted the modifications required by the administration.
What does this regulation establish?
The resolution formulates a favorable simplified environmental impact report for the storage module that hybridizes the Mulhacén Solar photovoltaic plant. The project consists of installing a 21.56 MW lithium-ion battery park within the existing Cilindro Solar photovoltaic plant, with an underground evacuation infrastructure of 51.86 meters.
The administration evaluated two alternative locations and designs. Alternative 2 was chosen, which places the battery park inside the PSFV Cilindro Solar with underground evacuation, as it is the option that minimizes risks to protected bird species, especially the Iberian imperial eagle.
The conditions fully accepted by the promoter are articulated in three areas:
| Area | Accepted condition |
|---|---|
| Hydrology | Design modifications to protect the hydrological network of the surrounding area |
| Cultural heritage | Specific measures to preserve the cultural heritage of the affected area |
| Wildlife | Bird protection measures, with special attention to the Iberian imperial eagle |
The project does not affect habitats of community interest, which simplified the assessment procedure. The process was carried out with consultations to multiple administrations, in accordance with the simplified environmental assessment procedure provided for in Law 21/2013.
Economic and operational impact
For Mulhacen Solar SL, this favorable report is the key that opens the door to the project's final authorization. Without it, the investment in the storage module cannot be legally materialized. With it, the promoter can initiate authorization procedures before the competent substantive authority.
From an operational perspective, the choice of alternative 2 —underground evacuation of 51.86 m versus other aerial options— entails a somewhat higher installation cost, but eliminates the main environmental risk identified: the impact on protected bird species. This decision reduces the likelihood of subsequent challenges that could paralyze the project.
For the energy sector in general, this case establishes a clear precedent on what the administration requires in photovoltaic hybridization plus storage projects in Castilla-La Mancha:
- Evaluation of location alternatives with the criterion of minimum impact on protected wildlife.
- Prior and formal acceptance of all required modifications before the report is formulated.
- Coordination with cultural heritage and hydrology administrations.
- Preference for underground evacuation solutions in sensitive areas.
Who does it affect?
- Mulhacen Solar SL: direct promoter of the project. Can advance toward final authorization.
- Castilla-La Mancha administration: substantive authority that must process the final authorization based on this favorable report.
- Municipalities of Esquivias and Numancia de la Sagra (Toledo): municipalities where the infrastructure is located, with competencies in territorial planning.
- Promoters of solar hybridization + storage projects: this case sets the standard for conditions required in similar procedures in Spain.
- Investors and financiers of renewable assets: the favorable report reduces the regulatory risk of the asset and improves its bankability.
- Environmental and engineering consultancies: reference for designing storage projects that pass simplified environmental assessment.
Practical example
Imagine a promoter developing a similar project: an existing photovoltaic plant in Castilla-La Mancha that wants to hybridize with a lithium-ion battery module. The Mulhacén Solar case offers a concrete roadmap:
In the design phase, you must evaluate at least two alternative locations for the battery park and justify which minimizes the impact on protected bird species. If the area has the presence of Iberian imperial eagle or other species in the protection catalog, the administration will require, at minimum, underground evacuation and specific protection measures.
Before the Directorate General formulates the report, the promoter must formally and in writing accept all required modifications regarding hydrology, cultural heritage, and wildlife. Only then —as happened with Mulhacen Solar SL— is the favorable report formulated that enables the step toward final authorization.
An infrastructure of 1,379 m² with underground evacuation of less than 60 meters, correctly designed and with environmental measures integrated from the start, has much better chances of passing simplified assessment without incidents that slow down the investment timeline.
What should companies do now?
- If you are Mulhacen Solar SL or its legal advisor: immediately initiate final authorization procedures before the competent substantive authority of Castilla-La Mancha, providing this favorable report as an enabling document.
- If you develop solar hybridization + storage projects in Spain: review case BOE-A-2026-13197 as a reference for the minimum conditions the administration will require in similar projects.
- If you are an investor or financier of renewable assets: update the regulatory risk analysis of the Mulhacén Solar asset, which improves substantially with this favorable report.
- If you are an environmental or engineering consultancy: incorporate the criteria from this case —location alternatives, underground evacuation, bird protection— in the designs of future storage projects in sensitive areas.
- If you operate in the municipalities of Esquivias or Numancia de la Sagra: verify if the project's advancement may generate coordination needs with the municipality regarding territorial planning or municipal services.
Frequently asked questions
What is the simplified environmental impact report and why is it essential?
It is the document issued by the Directorate General for Quality and Environmental Assessment after the simplified environmental assessment procedure regulated by Law 21/2013. Without this favorable report, the substantive authority cannot grant final authorization for the energy project. In the case of Mulhacén Solar, the resolution was formulated on June 3, 2026 and published on June 17, 2026.
Why was alternative 2 chosen and what does it imply technically?
Alternative 2 places the battery park inside the PSFV Cilindro Solar with an underground evacuation of 51.86 meters. It was chosen because it minimizes risks to protected bird species, especially the Iberian imperial eagle, compared to other options with aerial evacuation that would have generated greater risk of collision or electrocution for these species.
What conditions did the promoter have to accept to obtain the favorable report?
Mulhacen Solar SL fully accepted the required modifications in three areas: hydrology (design adaptations to protect the hydrological network), cultural heritage (measures to preserve the area's heritage), and wildlife (protected bird protection measures). Formal acceptance of these conditions was a prerequisite for formulating the favorable report.
Does the project affect habitats of community interest or protected areas?
No. According to the resolution, the 1,379 m² infrastructure does not affect habitats of community interest. This fact simplified the environmental assessment procedure and was one of the factors that allowed it to be processed as simplified rather than ordinary assessment.
What is the next step after this favorable report for the project to obtain final authorization?
The favorable environmental impact report is the prerequisite, but not the final authorization. Mulhacen Solar SL must now present this report to the competent substantive authority (the Castilla-La Mancha administration) to continue the project authorization procedure. Only after that final authorization can construction of the storage module begin.
Official source
View 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-2026-13197