Infrastructure-related impact

The construction and maintenance of high-voltage power lines is an activity with significant environmental impact. Elering owns overhead and cable lines that fall into two voltage categories: 110 kV and 330 kV.

Each line has a designated protection zone, which is the area of land, airspace, or body of water surrounding the electrical installation, where land use is restricted to ensure safety. The extent of the protection zone depends on the voltage level – for 110 kV lines, it is 25 meters on each side of the line’s center (a total of 50 meters), and for 330 kV lines, 40 meters on each side (a total of 80 meters).

In addition to ensuring high-quality electricity supply, the purpose of establishing and maintaining line corridors is to reduce the risk that power lines pose to the surrounding environment and to people. Trees falling onto power lines can cause significant damage – including forest fires – and a tree in contact with a live line poses a serious threat to nearby people and animals.

To improve the reliability of its power lines, Elering consistently installs bird deterrents, which also help protect birds from the dangers posed by high-voltage lines. On newer lines, especially those in bird migration corridors, overhead conductors are equipped with so-called marker balls that help birds detect and avoid the wires in time. In 2024, investments continued under the European Recovery and Resilience Facility to improve the capacity for connecting renewable energy sources in Western Estonia. As part of this, a second submarine cable was installed across the Väike Strait (in direct translation: Small strait), and a Soviet-era overhead line located on a causeway was dismantled, eliminating a hazard to bird movement—especially for swans.

Elering also continues to collect and dispose of materials left in the natural environment during line reconstructions in past decades, such as used insulators or parts of transmission towers.

In 2024, we dismantled and disposed of decommissioned line sections L183/L184 Laagri branch and L109/L110 Ellamaa branch. In total, 22 towers, over 14 route kilometers of conductor, approximately six route kilometers of lightning protection cable, and eight tower foundations were removed. In connection with the construction of the Väike Strait cable, 7.7 route kilometers of conductor and fiber optic lightning protection cable were dismantled and removed from section L174A Muhu–Orissaare overhead line. Additionally, 30 towers, including two steel towers with concrete foundations, were removed, freeing the area from outdated infrastructure and increasing environmental sustainability.

Underground Cable Lines

To improve safety and reduce visual pollution, Elering has launched the "Big Cities Go Underground" program in Tallinn and Tartu, through which the company will build dozens of kilometers of new cable lines to replace aging overhead lines in the coming years.

In Tallinn, Elering has installed approximately 50 kilometers of underground cable over the past ten years as part of the program. In the districts of Haabersti, Põhja-Tallinn, Kristiine, and Mustamäe, this has freed up large areas of land from usage restrictions, allowing the city and private owners to utilize the space more freely.

In Tartu, by 2030, Elering will replace all 110 kV overhead lines surrounding the densely populated areas of the city with underground cables. The total length of the new cables will reach several dozen kilometers. The cables will connect Elering’s substations: Tartu and Emajõgi, Tartu and Anne, Tartu and Tööstuse, and Tööstuse and Anne.

Green Corridors

The protection zones of high-voltage lines can provide habitats for various animal and plant species, though for some species, these wide areas may present a challenge. In 2024, Elering and the State Forest Management Centre (RMK) jointly established several green corridors in Alutaguse municipality, Ida-Viru County, to support the movement of flying squirrels, allowing them to safely cross line corridors and maintain their travel routes.

Infrastructure Design

Elering invests in infrastructure design to minimize the negative impacts of its core activities on communities and to make energy infrastructure more visually suitable for local residents. At the beginning of 2024, we erected Elering’s third design pylon, “Little Crane,” in Mustvee—combining engineering solutions with a nature-inspired aesthetic. Additionally, the Kuusalu substation received a new visual look, featuring a beautiful butterfly motif that complements the local landscape and is clearly visible from the Tallinn–Narva highway.

Read more about design pylons

Electricity transmission cannot exist without electric and magnetic fields. Every energized electrical conductor or device—from high-voltage power lines to household appliances—generates electric and magnetic fields around it.

Electromagnetic fields (EMFs) consist of electric and magnetic fields that propagate together at the speed of light. They are characterized by their frequency and wavelength. Frequency refers to the number of oscillations per second, measured in hertz (Hz), where 1 Hz equals one complete cycle per second.

The strength of the fields surrounding power lines depends on the voltage of the overhead line and the amount of current flowing through the line at any given moment. The field is strongest near the line and diminishes significantly with distance. Additionally, the strength of the electric field depends on many factors such as the height of the towers, the configuration of the conductors on the towers, and the number of circuits per tower.

In practice, electric and magnetic fields act independently and are measured separately.

• Electric fields are generated by voltage—the higher the voltage, the stronger the resulting field. The unit of measurement for electric field strength is volts per meter (V/m) or kilovolts per meter (kV/m).
• Magnetic fields result from the movement of electric charges, i.e., electric current: the greater the current, the stronger the magnetic field. Magnetic field strength is typically described in terms of magnetic flux density, measured in tesla (T), millitesla (mT), or more commonly microtesla (μT).

The following diagram illustrates the maximum magnetic field values near and directly beneath power lines.(in estonian)

In living environments, electromagnetic field strength must not exceed the nationally established limit values. (The permissible limits for electric and magnetic field strength are set by the Minister of Social Affairs’ regulation No. 38 of 21 February 2002, “Limit values for non-ionizing radiation in residential and recreational areas, dwellings, public buildings, classrooms, and measurement of non-ionizing radiation levels.” These same limits are also established in Estonian standard EVS-EN 50341-3-20:2007 and in the recommendations of the Council of the European Union.)

According to the established limits, the electric and magnetic fields from 50 Hz electromagnetic radiation must not exceed the following values in residential environments:

• Electric field strength – 5000 V/m (5 kV/m)
• Magnetic flux density – 100 μT (0.1 mT)

If electric and magnetic field values remain within the allowed limits, they do not pose a negative impact on human health.

Electromagnetic fields caused by overhead lines can induce currents and voltages in nearby conductive objects.
The effects of induction must also be considered for long metallic structures (e.g., communication installations, fences, pipelines) or large conductive objects (e.g., metal roofs, tanks, or large vehicles) located near power lines.

Most effects are associated with induced voltages in metallic structures and objects that are not properly grounded. In such cases, each conductive part of the object must be grounded accordingly.

We maintain annual records of activities and expenses related to preventing environmental pollution (e.g., oil-related operations, volumes of hazardous waste disposal). The aim is to prevent potential pollution associated with maintenance work and the decommissioning of outdated equipment.

According to the new EU F-gas Regulation (EU) No. 2024/573, the use of new switchgear with a rated voltage of 52–145 kV that employs fluorinated greenhouse gases as insulating or arc-quenching media—or is based on such gases—will be prohibited as of 1 January 2028. In line with this, Elering has adopted a procurement guideline stating that, starting from 1 April 2025, new switchgear with a rated voltage of up to and including 110 kV must not use fluorinated greenhouse gases as insulating or arc-quenching media. In older substations, we are continuously implementing necessary upgrades to reduce any potential environmental impact.

Additionally, operational substation equipment can generate noise that may disturb the surrounding area. All new transformers are built to strict standards, and we prefer suppliers whose transformers have lower noise levels. Noise limits are especially stringent in nature conservation areas. To mitigate noise propagation, Elering has installed sound barriers for transformers at critical locations. Each year, Elering conducts 3–4 noise level measurements, which have confirmed that the noise remains within permissible limits.

Safety Measures and Accident Prevention at the Kiisa Emergency Power Plants

In 2024, we replaced 124 aged pipes at various locations along the pipeline network, totaling 1,492 meters. Additionally, we refurbished 15 worn-out gas pipes using composite sleeves and updated insulation, covering a total of 1,047 meters. Altogether, Elering upgraded 2,539 meters of gas pipelines during 2024.

To ensure corrosion protection of the pipelines, anode grounding systems at three cathodic protection stations were upgraded. Elering’s gas network uses self-regulating cathodic protection stations that adapt to environmental conditions. This solution slows down the corrosion rate of pipelines, contributing to a gradual decrease in the number of pipes requiring replacement within the gas network.

In addition to its onshore infrastructure, Elering also operates offshore infrastructure with cross-border connections in the Gulf of Finland. When constructing such communications infrastructure, it is essential to assess the impact on marine biodiversity. In 2024, the Environmental Monitoring Authority conducted studies in the Balticconnector pipeline installation area. The results indicated that such infrastructure may actually promote biodiversity—for example, small fish were observed using the pipeline as shelter, creating a protected habitat for them.

Activities at Pipeline Valve Stations

In 2024, we built the necessary connections for mobile compressor equipment at the Varudi, Kalmaru, Lokuta, Navesti, and Veriora pipeline valve stations. This enables a significant reduction in atmospheric methane emissions during future pipeline maintenance and repair works, thereby supporting our efforts to reduce environmental impact and meet climate goals.