Biodiversity is one of the most important environmental descriptors taken into account in the systematic assessment of the potential impacts of REN's activities in the various phases of the life cycle of its infrastructures.
For this reason, the company's activities in this matter are structured in accordance with the following lines of action:
In 2008 REN joined the Business and Biodiversity (B&B) initiative, establishing for this purpose a Memorandum of Understanding with the Instituto de Conservação da Natureza e da Biodiversidade which included a LIFE+ project in partnership with the Liga para a Protecção da Natureza. This project included a number of conservation actions for three species of steppe birds (the great bustard, the little bustard and the lesser kestrel) in areas of the Rede Natura 2000 in the Baixo Alentejo.
For more information consult the Annual Report.
REN conducts regular awareness-raising and responsibility actions to involve the various social actors in land management. They include farmers, hunters, forest managers, central, regional and local government officials and business people. In addition, special attention is given to the involvement of all employees, suppliers, and service providers working with REN.
REN implements various measures to minimise effects on areas of high-value biodiversity, establishing several partnerships with environmental NGOs in order to develop studies to mitigate or offset the impacts caused by our activities on biodiversity.
In the construction of very high voltage lines, REN seeks to minimise the occurrence of impacts on birds by selecting locations that avoid the most critical situations of compatibility with habitats and migration routes of some species. However, these initiatives are not always enough to prevent the existence of negative impacts. In these cases, it is necessary to identify and implement additional mitigation measures.
To minimise the possible collision of birds, signalling devices called Bird Flight Diverters (BFDs) are usually installed, which are spiral-shaped devices with double fixation, about 30 cm in diameter and 1 metre in length. They come in orange and white colours. The spacing between these devices in the potentially most impactful line sections takes into account the territory zoning defined in joint studies with the ICNB.
Since 2009, REN has been carrying out an ongoing study in partnership with QUERCUS, in order to evaluate the effectiveness of new anti-collision devices in reducing the collision of wild birds with RNT cables. These are called FBFs - Firefly Bird Flappers.
The Baixo Alentejo region was selected for this study based on data collected in previous studies (protocol REN - Instituto de Conservação da Natureza e da Biodiversidade), enabling the evaluation of the effectiveness of the installation of devices for species such as the great bustard, the little bustard and the crane. These devices were installed on the lines of Ferreira do Alentejo - Évora and Palmela - Évora, both 150 kV. The study has also assessed the impact of the FBFs on noise descriptors as well as on the landscape. It was concluded that the use of these devices does not induce a significant change in these descriptors.
Within the scope of this European Union Business and Biodiversity Initiative, REN has participated in the LIFE+ Steppes Project, which aims to promote the conservation of birds in the corn-producing steppes of the Baixo Alentejo. The project involves, in particular, three vulnerable species: the great bustard (Otis tarda - endangered species), the little bustard (Tetrax tetrax - vulnerable species) and the lesser kestrel (Falco naumanni - vulnerable species) and operates in three areas of the Rede Natura 2000 classified as Special Protection Areas (SPA): Castro Verde, Vale do Guadiana and Mourão/Moura/Barrancos.
For more than ten years REN has been controlling the nesting of the white stork population in its infrastructures by creating conditions so that these birds may nest in favourable habitats, and by installing devices that minimise the risk of accidents of electrical origin. Continuing with the work developed in previous years, several nesting platforms for birds have been installed, to which the nests located in support areas considered at risk for the birds were transferred. In these locations, devices to inhibit the birds’ perching and nesting were also installed. All these interventions are annually reported to the Instituto de Conservação da Natureza e da Biodiversidade through a descriptive report specifying the measures implemented throughout the year, complemented by the analysis of the historical evolution of the situation and associated indicators.
In 2013 the following steps were performed:
- 97 platforms for building nests and laying of artificial nests, and;
- 649 anti-perching devices.
51 nests that were at risk were transferred to artificial platforms.
In 2013, there was a slight reduction in the rate of incidents involving white storks as compared to 2012
The aim of heightening of lines was to minimise the impact caused by the National Electricity Transmission Grid's corridor lines on the cork and holm oak forest and on the species that use this forest as a habitat.
The project began with the selection of the most critical spans on the basis of their strip maintenance history, the distance of the trees from the conductors measured by laser from a helicopter and the type of vegetation in each span, in order to decide which pylons needed heightening.
The lines selected for this purpose, the 400kV Palmela-Sines 2 and 3 lines, cross areas with a considerable number of cork oak groves, and it was therefore necessary to carry out annual pruning of the treetops to ensure compliance with the safety distance regulations for line conductors.
The changes made on the two lines consisted of heightening 107 pylons, increasing the distance between the line conductors and the top of the cork oaks, in the spans permitted by these pylons, up to a maximum of 6 metres. This measure is expected to prevent the need for annual pruning of around 4,250 trees.
The reduction in the number of trees affected by such pruning will help to protect the species in question, in particular the cork oak, as well as the biodiversity of the habitat.