Determination of environmental impact in renewable energy projects

La determination of environmental impact has become a key element in accelerating the implementation of renewable energy projects In Spain, environmental protection is paramount. This procedure is designed to be faster than a standard environmental impact assessment, but without compromising the analysis of the effects on nature, the land, and people. In practice, it involves a meticulous examination of whether a project will generate significant environmental impacts and, based on that, a decision is made as to whether it can proceed under the current conditions or whether, on the contrary, it must undergo a full environmental assessment.

In recent years, especially as a result of the energy crisis and the war in UkraineA specific regulatory framework has been approved (primarily Royal Decree-Law 6/2022 and Royal Decree-Law 20/2022) that shapes this procedure for renewable energy projects under state jurisdiction. This legal framework has already been applied in real-world cases, such as the Torozos C hybrid photovoltaic solar plant (Valladolid), which serves as a very illustrative example for understanding exactly what is considered in an environmental impact assessment and what kind of measures are required of developers.

What is environmental impact assessment and what is it used for?

The determination of environmental impact is, in essence, the quick and specific report This document is issued by the environmental authority to assess whether a renewable energy project can continue its authorization process without undergoing a standard or simplified environmental assessment, or whether, on the contrary, this more comprehensive procedure is necessary. It does not replace the environmental impact assessment regulated by Law 21/2013 of December 9, but it serves as a preliminary filter in a very specific context.

According to current regulations, this procedure is conceived as a urgent response The need to reduce energy dependence, contain prices, and ensure supply is addressed by facilitating the implementation of renewable energy installations, provided they do not have significant adverse environmental effects. The idea is clear: to accelerate the energy transition, but with sufficient environmental safeguards.

In legal terms, the environmental body analyzes the technical documentation submitted by the developer (preliminary project, environmental impact study and an executive summary focused on certain criteria) and prepares a environmental impact assessment reportThis report may be favorable (allowing the project authorization process to continue, with conditions) or it may conclude that the project must be subject to the environmental assessment provided for in Law 21/2013.

This procedure takes place within the substantive authorization procedure of the project (or within the control mechanisms for activities with responsible declaration or prior communication) and analyzes effects on population, human health, fauna, flora, biodiversity, geodiversity, air, water, soil, subsoil, climate and climate change, landscape, material goods (including cultural heritage) and the interaction between all these factors.

Regulatory framework and scope of application

The procedure for determining the environmental impact of renewable energy projects is framed, primarily, within the Royal Decree-Law 6 / 2022, of March 29, And in the Royal Decree-Law 20/2022, of December 27These rules establish both the abbreviated procedure for environmental analysis and the special conditions for urgent processing of renewable generation projects under the jurisdiction of the General State Administration.

The Directorate General for Environmental Quality and Assessment, within the Ministry for Ecological Transition and the Demographic Challenge, is the competent state environmental authority to resolve these procedures when dealing with projects within its scope (for example, large electricity generation facilities or associated evacuation infrastructure). Its competence is based, among other regulations, on Royal Decree 500/2020, of April 28, which develops the basic organizational structure of the Ministry.

It's important to understand that not all renewable energy projects are eligible for this expedited procedure. The following are excluded, among others:

• Facilities located in the Natura 2000 Network (SPAs and SACs) or in protected natural areas defined in Law 42/2007, on Natural Heritage and Biodiversity.
• Projects located in marine environment.
• Construction of overhead power lines with a voltage equal to or greater than 220 kV and a length greater than 15 km.

In these cases, the ordinary regime applies directly. environmental assessment of Law 21/2013, without going through the determination of environmental impact. For the rest of the projects under state jurisdiction, this abbreviated procedure is applied on an exceptional and temporary basis, and it is required that the application for administrative authorization be submitted within the period of validity established by law (until December 31, 2024, according to Royal Decree-Law 20/2022).

Furthermore, Article 23 of Royal Decree-Law 20/2022 introduces procedures simplified authorization For projects that already have a favorable environmental impact assessment report, these applications are processed urgently, applying the reduced timeframes established in Law 39/2015 and the specific provisions outlined in that same article, always maintaining the basic reference to Royal Decree 1955/2000 regarding electrical power installations.

Documentation that the promoter must submit

To initiate the procedure for determining environmental impact, the promoter The project manager (company or responsible organization) must submit a series of very specific documents to the substantive authorization body. The substantive body, in turn, will forward them to the environmental authority if they are complete, or will request corrections if there are any deficiencies.

The basic documentation that must be submitted includes:

• Specific request of determining environmental impact for renewable energy projects, complying with the general administrative requirements of Law 39/2015.
• El blueprint of article 53.1.a) of Law 24/2013, of the Electricity Sector, where technical characteristics, location, evacuation infrastructure, etc. are described.
• Un Environment Effect investigation that complies with the contents of articles 5.3.c) and 35 and annex VI of Law 21/2013.
• Un executive Summary that quantifies and explains the expected impacts, specifically with respect to the environmental criteria indicated in the Royal Decree-Law (Natura Network, biodiversity, discharges, waste, natural resources, cultural heritage, socio-economic impact and synergies).

If the documentation is incomplete, the competent authority will initiate a rectification procedure in accordance with Article 68.1 of Law 39/2015. If the promoter does not correct the deficiencies within the established timeframe, they will be deemed to have failed to comply. withdrawn from his applicationWhen the file is correctly compiled, it is sent to the environmental body within a maximum period of ten days.

In practice, many engineering and environmental companies offer services of advice on drafting these documentsThis optimizes both the technical content and regulatory alignment. This is the case for firms like GTA Ingeniería y Medio Ambiente, which already work regularly with this new regulatory framework and are well aware of the type of information and level of detail required by the Administration.

Contents of the executive summary and analysis criteria

The core of the procedure lies in the executive Summary This report, prepared by the project developer, must summarize the project's main environmental impacts both quantitatively and qualitatively. The regulations establish eight main areas of analysis, which are then used by the environmental authority to structure its report.

These criteria, which are applied both generically and very specifically in cases such as the Torozos C hybrid photovoltaic plant, are as follows:

1. Impact on Natura 2000 network, protected areas and habitats of community interest

It is analyzed whether the project falls within any protected natural spaceSPAs or SACs of the Natura 2000 Network, or if it is located near them and could affect their ecological values ​​or their buffer zones. The presence of Habitats of Community Interest (HIC) and other categories such as Public Utility Forests or Listed Wetlands.

In the case of the Torozos C hybrid photovoltaic plant, the analysis concluded that there is no territorial overlap with protected natural areas in Castile and León. The nearest Special Protection Areas (SPAs) and Special Areas of Conservation (SACs) are located more than 12 km from the project area, and there is no presence of Historic Concerns (HIC) nor direct impact on Public Utility Forests, although the proximity of Public Utility Forest No. 140 "Las Higueritas" was recorded at approximately 2,5 km in the vicinity of the project and 1 km in the case of the power evacuation line.

2. Impact on biodiversity and protected species

This criterion reviews the possible impact on the protected or threatened flora and faunaThis includes species listed in the Spanish Catalogue of Threatened Species (CEEA), the LESPRE, or regional lists. Habitats for breeding, feeding, and resting are studied, as well as the presence of bats, steppe birds, birds of prey, breeding colonies, roosts, etc.

In Torozos C, the plant is located mainly on dryland agricultural land, where the use of pesticides This can affect biodiversity; with ruderal vegetation along roadsides and boundaries, and no detection of protected flora during fieldwork, despite historical records within a 10 km radius. The avifauna study (May 2022 – April 2023) recorded 58 bird species in the field, with particular attention to:

• Red kite (Milvus milvus), in danger of extinction, with the presence of up to 33 specimens and a winter roost more than 12 km from the project.
• Montagu's Harrier (Circus pygargus), listed as vulnerable, with reproductive behaviors detected about 5,7 km from the plant.
• Great Bustard (Otis tarda), a species of steppe interest included in the LESPRE, observed on a point basis, with a maximum group of 27 specimens 4 km from the plant and no evidence of reproduction in the immediate area.

No specimens of little bustard (Tetrax tetrax) or sandgrouse (Pterocles orientalis and Pterocles alchata) were found, with only ancient historical references existing from a long time ago or without recent confirmation. Several species of bats were also identified, such as the dwarf bat, garden bat and long-tailed batIn addition to bibliographic references to mouse-eared bats and southern long-eared bats, no bat roosts were found in the implementation area, with the nearest one located almost 5 km away.

The environmental sensitivity mapping of the Junta de Castilla y León classifies the project area as low sensitivity for steppe birds and of medium sensitivity for soaring birds. Despite this favorable classification, reinforced measures for monitoring and conservation of fauna, especially steppe fauna, and for controlling mortality associated with panels, fences, and power lines are necessary.

3. Impact of spills into public waterways and public water domain

This section assesses whether the project can generate discharges into surface or groundwater, if it is located in flood-prone areas, preferential flow areas or river police areas, as well as the possible contamination derived from earth movements, sediments and runoff.

For Torozos C, several streams linked to the Duero Hydrographic ConfederationThe plant has no direct territorial overlap with the plant or the interconnection line. The nearest watercourse, the Arroyo de los Molinos or Arroyo de Juncos Gordos, is approximately 860 meters away. The plant is located outside the Duero River's Areas of Significant Potential Flood Risk (ARPSIs), considerably reducing the risk of flooding. During operation, no wastewater is generated; instead, watertight tanks or temporary chemical sanitation facilities are used during construction.

The resolution requires the implementation of a detailed hydrological study that delimits the public water domain, easement and police zones, flood-prone areas, and preferential flow zones. The installation of infrastructure in the preferential flow zone is prohibited, and any fences must be permeable to avoid altering drainage capacity or accumulating materials susceptible to erosion during periods of heavy rain.

4. Impact of waste generation

The construction, operation and dismantling of the project generate waste of very diverse nature: rubble, concrete and wood debris, packaging, contaminated containers, oils, lubricants, and other hazardous waste. The environmental impact study for Torozos C estimates, for example, approximately 2,47 tons of hazardous waste and more than 145 tons of non-hazardous waste, with a significant amount coming from transformer substations, pipelines, and fencing.

The project must include specific storage areas, with segregated storage For hazardous waste and written records of movements, ensuring that all waste is delivered to authorized waste management companies. Minimizing waste generation, recycling, and, in particular, optimizing the earthworks balance to reduce excavation surpluses are encouraged.

5. Impact of natural resource use and land occupation

Photovoltaic installations represent a prolonged occupation of the landThe work includes the opening of internal roads, interconnection trenches, and the installation of foundations for structures and transformer stations. In Torozos C, the affected area is around 100 hectares, with 12,4 km of fencing, 4,6 km of roads, and almost 13 km of low- and medium-voltage trenches.

The topsoil is removed at the start of the works for its subsequent reusestoring it in stockpiles with a maximum height of 2 m to prevent degradation. Most of the excavated soil is reused for internal fill, and only the excess is sent to gravel pits or landfills. During operation, water consumption is basically limited to cleaning photovoltaic panels, supplied by tanker trucks and without the use of detergents or other additives.

6. Impact on cultural heritage and livestock trails

Cultural analysis examines the existence of Assets of Cultural Interest (BIC)The area includes listed archaeological sites, historic roads, and livestock trails. In the Torozos C area, the nearest listed building is Torrelobatón Castle, about 4 km away, and the Páramo de Doña María archaeological site is 800 m from the proposed site. A previous archaeological survey did not detect any assets directly affected by the planned infrastructure.

The project borders the livestock trails Palomera Colada y Marialba's CordThe underground evacuation line crosses the Colada de la Palomera. The resolution requires prior authorization from the Territorial Environmental Service for any action affecting these routes, ensuring at all times the continuity of livestock passage and compatible uses, in accordance with Law 3/1995 on Livestock Routes.

7. Socioeconomic impact on the territory

The determination of environmental impact does not stop at nature: it also assesses the socioeconomic impact in the affected municipalities. In the case of Torrelobatón and Villasexmir, these are traditionally agricultural and livestock farming areas, where the construction of the photovoltaic plant will generate direct employment in construction and stable jobs in operation and maintenance.

They are valued additional income for municipalities and landowners (land occupation fees, taxes, etc.), as well as the potential impact on existing activities such as hunting (the plant's land is part of private hunting reserves) or the use of rural roads. The acoustic study concludes that the plant's activity will not cause significant noise levels and will comply with current regulations.

8. Synergistic effects with other projects

Finally, the following are analyzed: cumulative and synergistic effects with other nearby projects: wind farms, other photovoltaic plants and high-voltage power lines located within a minimum radius of 10 km for wind, 5 km for photovoltaics and 2 km for power lines.

In the area around Torozos C there is already a high density of renewable energy installationsThere are 15 operational or authorized wind farms (plus another one in the permitting process), nine existing or authorized photovoltaic plants, and various evacuation infrastructures. The total area occupied by all the photovoltaic plants represents approximately 2,6% of the area of ​​the 21 affected municipalities, with agricultural uses generally remaining on much of the land.

Visual analysis estimates that Torozos C facilities could be visible in 4 of the 26 population centers, and that in 3 of these, the effects will be cumulative with wind turbines, other photovoltaic plants, and high-voltage power lines. The area where the plant and other infrastructure would be visible is relatively small (around 3% of the study area). Regarding fauna, a reduction in foraging habitat for steppe birds is considered possible, although it is noted that many threatened species have a limited or sporadic presence in the specific project location, and that the reuse of existing evacuation infrastructure helps minimize new impacts.

Real example: Torozos C hybrid photovoltaic solar plant

The April 2024 resolution concerning the Torozos C Hybrid Photovoltaic Solar Plant This is a very comprehensive practical example of how environmental impact assessment is applied. The project involves a 38 MW photovoltaic plant to be hybridized with the 39,6 MW Torozos C wind farm, sharing a connection point and part of the evacuation infrastructure.

The plant anticipates a installed capacity of 42,10 MWpThe plant occupies approximately 99,7 hectares and transmits power via a 650-meter-long, 30 kV underground line to the existing ST Torozos 30/220 kV substation. From there, the power is transported to the ST Tordesillas 220 kV substation via an existing and operational overhead underground line with a total length of approximately 30,4 kilometers. The plant's perimeter fence extends for just over 12 kilometers.

After thoroughly analyzing all environmental criteria and the preventive, corrective and compensatory measures proposed by the developer, the General Directorate of Environmental Quality and Assessment concludes that No significant adverse effects were observed. Regarding the environment, provided that these measures and the additional conditions set out in the resolution are strictly met, the project can continue with the authorization process without undergoing a standard or simplified environmental assessment procedure.

The report further clarifies that the determination of environmental impact is not subject to appeal in itself, without prejudice to any appeals that may be filed against the project authorization. It also indicates that the draft report was sent to the Directorate General for Natural Heritage and Forestry Policy of the Regional Government of Castile and León, which had ten days to submit comments; as no comments were received within this timeframe, the report's content was deemed accepted in accordance with Royal Decree-Law 6/2022.

Preventive, corrective and environmental monitoring measures

A fundamental aspect of determining environmental impact is the package of measures which is imposed on the developer. In the case of Torozos C, the resolution includes a very broad set of conditions, many of which can be applied to other renewable energy projects processed through this channel.

Among the most notable measures, the following can be highlighted:

• Perform comprehensive field sampling prior to the start of the works, within a radius of at least 1 km, to detect nesting fauna, threatened flora and bat roosts, communicating the results to the provincial environmental service.
• Colaborating plots equivalent to 100% of the occupied area by the plant as habitat improvement areas for steppe birds, applying traditional fallow practices, late stubble removal, use of legumes and long-cycle cereals without pesticides, and maintenance of grasslands and herbaceous borders.
• Respect the nesting periods of the avifauna when planning the works, with a schedule coordinated with the territorial environmental service.
• Prepare a wildlife monitoring plan throughout the plant's lifespan, managed by an independent entity, with periodic censuses of steppe birds, birds of prey, bats and invertebrates, and monitoring of mortality associated with both panels and fences.
• Minimize earthworks, delimit auxiliary areas within the perimeter of the plant and avoid locating them in areas with natural values ​​or near waterways, livestock trails or wooded land.
• Install panels using pile driving systemsreducing the sealed soil surface, and allowing the development of herbaceous and shrubby vegetation under the modules, without the use of herbicides, resorting to mechanical clearing or grazing for maintenance.
• Reserve at least one 1% of the installation surface for patches of vegetation of about 0,5 ha, distributed in several areas as wildlife refuges, and maintaining the boundaries with natural vegetation.
• Install grid-like bands on some panels to reduce the mortality of insects and small birds, as well as clear plates on the fence and substation to improve their visibility.
• Avoid nighttime lighting, except when strictly necessary, using lights that do not emit white light rich in blues or UV and always directing the light towards the ground.
• Dejar patches of natural vegetation with "bug-hotel" type shelters for pollinators and to monitor them within the environmental monitoring program.
• Guarantee the permeability of the fence through ground-level wildlife crossings every 200m and set back the enclosures to reduce the barrier effect and leave connectivity corridors, especially at the boundary with other neighboring photovoltaic plants.
• Develop a green corridor through planting of local forest species at a density of 1.000 plants/ha, with certified reproductive material, irrigation, pruning and replacement of dead trees for at least ten years.
• Avoid installing nest boxes or perches near the associated wind farm to prevent increasing the risk of collision with wind turbines.
• Apply the measures of fire prevention of Order FYM/510/2013, restricting the use of machinery that may generate sparks during periods of high danger and having a Self-Protection Plan with periodic drills.
• Guarantee the land restoration once the useful life of the plant has ended, by submitting a Dismantling and Restoration Plan approved by the competent environmental service.

In addition, an intensive search for carcasses and wildlife remains is planned during the first year of operation, with fortnightly tours of all corridors between panels and on the outer perimeter of the fence, to calibrate the actual mortality associated with the installation and, if necessary, adjust the mitigation measures.

Overall, the determination of environmental impact is configured as a robust yet agile toolThis system combines a highly detailed impact analysis (with comprehensive examples such as the Torozos C case) with an expedited administrative procedure designed to accelerate the energy transition. When its criteria are correctly applied and robust prevention, mitigation, and monitoring measures are required, it allows for the authorization of significant renewable energy projects within tight timeframes without compromising a high level of protection for the environment, biodiversity, cultural heritage, and the well-being of the local population.