Key data
| Regulation | Resolution of June 3, 2025, from the General Directorate of Energy Policy and Mines |
|---|---|
| BOE Publication | August 22, 2026 |
| Entry into force | Not specified in the resolution |
| Project holder | Naturgy Vento, SAU |
| Solar project | Casa del Aire II Hybridization — 54.6 MW photovoltaic |
| Associated wind project | Casa del Aire II — 51 MW (already existing) |
| Location | El Bonillo, Albacete (Castilla-La Mancha) |
| Category | Energy / Renewables |
| Year | 2026 |
The General Directorate of Energy Policy and Mines has granted Naturgy Vento, SAU prior administrative authorization for the photovoltaic solar park called "Casa del Aire II Hybridization", with an installed capacity of 54.6 MW, in the municipality of El Bonillo (Albacete). The resolution, dated June 3, 2025 and published in the BOE on August 22, 2026, also includes authorization for the associated evacuation infrastructure.
The differentiating element of this project is its hybridization with the Casa del Aire II wind farm, of 51 MW, already existing in the same location. By sharing evacuation infrastructure, the project optimizes a scarce resource: grid connection points, whose acquisition is one of the main bottlenecks in the Spanish renewable sector.
What does this regulation establish?
The resolution grants prior administrative authorization —the first formal step in the process of enabling electrical generation facilities in Spain— for the photovoltaic solar park "Casa del Aire II Hybridization". This authorization also covers the evacuation infrastructure necessary to connect the new solar installation to the shared connection point with the already existing wind farm.
The processing included an environmental impact assessment with a favorable declaration issued in February 2025. This declaration incorporates specific conditions that the project must respect during its construction and operation:
| Environmental condition | Detail |
|---|---|
| Sabina protection | Specific measures to preserve this protected plant species in the project's area of influence |
| Watercourse crossings | Technical requirements for crossings of water courses during infrastructure construction |
| Maximum slopes | Limitation to 12% maximum slope on access roads and earthworks |
| Compensatory measures plan | Obligation to present and execute a habitat compensation plan for affected areas |
Regarding ownership, the project was originally promoted by Energías Alternativas Castilla La Mancha, SLU, a company that transferred ownership to Naturgy Vento, SAU in 2024, before the final resolution.
Economic and operational impact
Solar-wind hybridization is not just a technical decision: it has direct economic consequences for developers and for the renewable sector as a whole.
- Grid connection point optimization: Sharing evacuation infrastructure between the 54.6 MW solar and 51 MW wind significantly reduces grid connection costs, which in independent projects can amount to tens of millions of euros.
- Higher node capacity factor: The complementarity between solar generation (daytime) and wind (more nocturnal and seasonal) allows more efficient use of the connection point, increasing effective hours of grid injection.
- Reduction of regulatory risk: By leveraging an already authorized and operational wind farm, the solar project reduces timelines and administrative uncertainty inherent in projects from scratch.
- Ownership transfer as a market signal: The transfer of the project from Energías Alternativas Castilla La Mancha, SLU to Naturgy Vento in 2024 reflects the active dynamics of buying and selling renewable projects in the processing phase, a common practice in the Spanish market.
Who does it affect?
- Naturgy Vento, SAU: Project holder, responsible for complying with environmental conditions and advancing in the following authorization phases (administrative construction authorization and service commissioning certificate).
- Local administration of El Bonillo (Albacete): Municipality where the project is located, with implications for land planning, local employment during construction, and collection of municipal taxes.
- Renewable energy developers and promoters: The resolution consolidates the hybridization model as a preferred route to optimize connection points, with strategic implications for any company managing wind assets susceptible to solar hybridization.
- Renewable asset investors: The pre-authorization ownership transfer confirms the value of projects in processing as tradable assets.
- Grid operators (REE/distributors): Hybridization affects evacuation capacity planning in the area.
Practical example
Imagine a renewable developer that has a 50 MW wind farm in operation in Castilla-La Mancha with underutilized evacuation capacity during central daytime hours (when wind is lower). Following the model of the "Casa del Aire II Hybridization" project, this developer could:
- Request authorization to add up to ~54 MW of hybridized photovoltaic solar capacity, without needing a new independent connection point.
- Share the already amortized evacuation infrastructure of the wind farm, avoiding connection costs that in a new project can exceed 5-10 million euros depending on distance to the substation.
- Submit the project to environmental impact assessment, incorporating from the start the usual conditions in Castilla-La Mancha: protection of protected vegetation (such as sabinas), control of maximum slopes of 12% and habitat compensation plan.
- Consider selling the project in processing to a larger operator —as happened with the transfer to Naturgy Vento in 2024— if seeking liquidity before construction.
What should companies do now?
- Audit existing connection points: If you have wind or solar farms with underutilized evacuation capacity, analyze whether they are candidates for hybridization. Naturgy's resolution confirms that the Administration supports this model.
- Review applicable environmental conditions: In Castilla-La Mancha, hybridization projects must contemplate from design the protection of sabinas, watercourse crossings and limitation of slopes to 12%. Incorporating them late increases costs and delays the project.
- Prepare the habitat compensatory measures plan: The favorable environmental impact declaration of February 2025 requires this plan. Having it ready before requesting construction authorization speeds up timelines.
- Assess the project's corporate structure: The transfer of ownership from Energías Alternativas Castilla La Mancha to Naturgy Vento in 2024 shows that projects in processing have market value. If seeking partners or partial divestment, act before construction authorization.
- Monitor BOE publication of the following phases: Prior administrative authorization is only the first milestone. Construction and service commissioning authorizations are the next critical steps for the investment timeline.
Frequently asked questions
What is solar-wind hybridization and why does Naturgy use it in Albacete?
Hybridization consists of combining two renewable generation technologies —in this case, photovoltaic solar (54.6 MW) and wind (51 MW)— at the same grid connection point, sharing evacuation infrastructure. Naturgy Vento applies this model in El Bonillo (Albacete) to maximize the use of the connection point of the already existing Casa del Aire II wind farm, reducing costs and optimizing energy injection to the grid in different time slots.
What environmental conditions must Naturgy's solar park in El Bonillo comply with?
The favorable environmental impact declaration, issued in February 2025, establishes four main conditions: protection of sabinas (plant species protected in the area), technical requirements for watercourse crossings, maximum slope of 12% on roads and earthworks, and the obligation to present and execute a habitat compensatory measures plan for affected areas.
Who was the original project holder and when was it transferred to Naturgy?
The project was originally promoted by Energías Alternativas Castilla La Mancha, SLU. Ownership was transferred to Naturgy Vento, SAU in 2024, before the prior administrative authorization resolution was issued.
What is the total combined capacity of the hybridization project in El Bonillo?
The total combined capacity between the new photovoltaic solar park (54.6 MW) and the already existing Casa del Aire II wind farm (51 MW) amounts to 105.6 MW, all of them evacuated through the shared connection infrastructure.
What steps remain pending after prior administrative authorization?
Prior administrative authorization is the first formal milestone. Next, Naturgy Vento must obtain administrative construction authorization and, once the project is executed, the service commissioning certificate. Each phase may incorporate new conditions or require additional documentation before the General Directorate of Energy Policy and Mines.
Official source
Consult complete regulation in official source (BOE-A-2026-18031)
Notice: This article is purely informational 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-2026-18031