Our goal is to manage our environmental impacts in such a way that our electricity network and our activities pose no risk or harm to the environment at all.

  • In 2016, Kuusakoski processed about 15% of the demolition materials from Caruna’s network projects and the rest was dealt with by contractors through their contractual partners.
  • Caruna pledged to improve its energy efficiency by continuing to the next period of the Energy Efficiency Agreement from 2017 to 2025.
  • In their first year, the solar panels fitted onto the roof of our head office produced more than 14 MWh of electricity for the building.
  • In 2016, we phased out 250 pole transformers from groundwater areas in order to reduce the risk of groundwater contamination caused by oil spills.
  • The quantity of oil spills remained the same: there were seven involving more than 100 kg of spillage.

Key environmental impacts

We identify and assess our environmental impact on a regular basis. The following table lists the most important environmental impacts associated with our operations, as well as the main measures for managing them.

Environmental impact Target Management measure Indicator
Handling and recycling of materials dismantled from electrical networks
  • Continuous improvement of the recycling rate of dismantled materials
  • Uninterrupted handling and recording process
  • The composition, safe usage and disposal methods of materials are already ascertained during the acquisition stage
  • Handling, recycling and disposal of dismantled materials, selection of contractual partners and verification of the compliance of all operations
  • Instructions, follow-up and monitoring
  • Waste accounting (tonnes and euros)
  • Recycling rate (%)
  • Internal audits (number)
  • Supplier audits (number)
Any oil spills into the environment caused by damaged transformers
  • Prevention of oil leaks
  • Absolute prevention of serious and permanent environmental damage
  • Elimination of risky items: renovation of pole transformers situated within groundwater areas
  • Prevention of oil leaks into the environment by installing oil collectors for substation transformers, building transformer rooms and pad-mounted secondary substations
  • Prompt handling of oil leaks and verification of the effectiveness of the measures by taking soil samples
  • Number of pole transformers within groundwater areas
  • Number of oil leaks
  • Costs of oil leak handling


Environmental management included in the post-project tasks of network maintenance and building
  • Areas surrounding project sites are restored to a condition that is at least as good as prior to the project
  • Contractor guidance, monitoring and supervision
  • Customer feedback reviewed jointly
  • Site inspection observations (number)
  • Customer feedback (number)
Environmental impacts associated with forest operations near overhead power lines
  • Minimisation of environmental impacts resulting from such clearance work
  • Investigation of protected areas and other sites vulnerable to disturbances during the planning and implementation of the project’s felling stage
  • Reporting of potential anomalies
  • Anomalies (number)
  • Customer feedback (number)
Handling of impregnated poles
  • Verification of the safety and conformity of pole handling and recycling
  • Minimisation of the number of new overhead line networks
  • No poles impregnated with hazardous substances (creosote) in use
  • Safe handling and appropriate recycling of existing overhead line network poles and dismantled poles that contain carcinogens
  • Number of poles sent for recycling
  • Criminal offence reports on poles stolen from dismantled sites (number)
  • Pole supplier audits (number)
Responsible land use and stakeholder collaboration
  • Minimisation of environmental and landscape impacts
  • Stakeholder satisfaction


  • Underground cabling considerably decreases land use restrictions and other environmental and landscape impacts
  • Selection of routes and structures
  • Smooth land use-related collaboration with land owners and other stakeholders
  • Level of cabling (%)
  • Stakeholder satisfaction as part of the survey on reputation
Impacts on biodiversity
  • Minimisation of conflicts between electricity networks and the natural environment already at the planning stage
  • Protected areas and objects are taken into consideration as early as possible
  • Support of positive environmental impacts in collaboration with stakeholders
  • Sightings of endangered species in the Caruna network area

Use of materials

We have made large investments to ensure a weatherproof and reliable electricity network. The numbers of purchased components for network building and the quantities of raw materials these contain are also considerable. Underground cables, pad-mounted secondary substations and distribution transformers are the main components of networks. We subject our material acquisitions to strict requirements right from the time tenders are invited. Environmental impacts, for instance, are given considerable weight in the consideration of these tenders. We investigate the component material compositions, potentially dangerous and hazardous characteristics, safe use and correct recycling at the end of their life cycle during the acquisition stage.

We connect almost 4,000 new distribution transformers to our electricity network every year. In terms of raw materials, this signifies roughly 400 tonnes of aluminium, 1,500 tonnes of steel and 600 tonnes of mineral oil. The new distribution transformers we use comply with the Ecodesign Directive.

The cables we use contain only aluminium as their conductive material. Annually, we acquire at least 1,500 kilometres of cable which contains about 1,300 tonnes of aluminium.

We acquire some of the materials we use directly and some indirectly via our contractors. Since 2016, we have increased our direct acquisition of materials. This clarifies our follow-up and reporting procedures.

Requirements for land use and landscape impacts

Electricity networks have both a physical and visual impact on their environment. Considerable investments into weatherproof underground cable networks reduce the restrictions and harmful effects related to the use of land near electricity networks and free the land for other uses. Landscapes and sceneries improve as overhead cables are eliminated.

We strive to reconcile the needs and expectations expressed by various stakeholders, regarding the selection of power network routes and structures. Whenever possible, new electricity networks are built alongside roads and in public areas. Smooth collaboration with land owners, municipalities, ELY Centres, the National Board of Antiquities, environmental organisations and other stakeholders in all matters regarding land use is of primary importance.


Underground cabling protects biodiversity and lessens the impact of electricity networks on plants and animals. We also do our best to prevent the risk of bird collisions and electric shocks by installing marker balls on overhead lines and landing perches on poles.

We assess the impacts of our network improvement programmes on biodiversity right from the planning stage and when applying for the necessary licences.

Energy usage

The majority of the energy used by Caruna consists of the transmission and transformer losses of the electricity network. The distribution of electricity always involves some loss, and the electricity distribution company is responsible for it. We strive to enhance the energy-efficiency of our networks and to reduce losses. Since the autumn of 2015, all new distribution transformers used by Caruna are low-loss ECO transformers compliant with the updated EU Directive.

We use CO2-free (zero carbon dioxide emissions) electricity to compensate for grid losses. In 2016, we purchased 389.3 GWh of electricity to compensate for the loss of electricity.

In addition, the standby power plants in our network area require small amounts of fuel. Our contractors acquire the fuel needed.

Own consumption of energy

Caruna’s own consumption of energy mainly consists of the electricity and heat energy used in our office buildings.

Caruna’s own consumption of energy mainly consists of the electricity and heat energy used in our office buildings. The majority of our own energy consumption takes place at our premises on Upseerinkatu in Espoo where we moved in September 2015. In 2016, we consumed 2.21 GWh of electricity and 1.82 GWh of heat energy.

The majority (nearly 75%) of the energy is used for cooling down the servers and the substation control room, as well as for cooling, heating and ventilating the rest of the building. Other significant energy consumption functions are water heating and lighting, for instance. The energy consumption of the restaurant operating in the building has not been taken into account in Caruna’s energy consumption.

In the Upseerinkatu offices, we use ground heat as well as district heating for operating the air conditioning.

Own energy production

Caruna has two production sites for solar power.

Caruna has two production sites for solar power whose main purpose is to collect first-hand experience of decentralised energy production.

At the end of 2015, we had 110 solar panels installed on the roof of our offices on Upseerinkatu. The nominal output of these solar panels is roughly 29 kWp. In 2016, their total energy production was over 14 MWh, which we utilised on the premises.

In addition, there are 119 solar panels on the roof of our primary substation in Keilaniemi, Espoo. In 2016, their total energy production was over 24 MWh. We used about 10 MWh of this at the substation and transferred the rest to our distribution network to compensate for network losses.

Energy Efficiency Agreement

Energy efficiency is a key part of Caruna’s environmental responsibilities and customer cooperation. We have been involved in the National Energy Efficiency Agreement and the Energy Conservation Agreement preceding it since the beginning of the agreement system in 1997. The previous agreement term closed at the end of 2016, and Caruna also acceded to the contract of the new agreement season 2017–2025.

Our extensive network improvement programme reduces network losses.

We are committed to taking energy efficiency into account in all our internal operations and to make our own energy consumption more effective, especially when it comes to grid losses. Our extensive network improvement programme reduces network losses. We take losses into account and reduce them also through careful network planning, our choice of components and the optimisation of the basic connection state.

In addition, we are committed to improving our customers’ awareness of their own energy use and the potential for making it more efficient. We offer them, for example, an energy reporting service, energy efficiency counselling and guidance in adopting their own energy production.

Greenhouse gases

Sulphur hexafluoride, or SF6, is a potent greenhouse gas, but also an excellent insulator in electrical devices. Due to the use of the gas, SF6-isolated devices are equipped with moisture protection, which decreases the risk of inadvertent electric shocks and enhances both the safety of the network and the occupational safety of our contractors.

We monitor all equipment for potential SF6 gas leaks and minimise the possibility of environmental impacts resulting from such leaks by systematic control, inspections and maintenance. We also monitor the SF6 gas status of all equipment while carrying out regular inspections. Any gas leaks and doubts related to gas meters are documented and recorded. We keep a record of our SF6 gas balance and leaks, and report this data to the branch organisation Finnish Energy (Energiateollisuus ry) once a year. We require all contractors handling SF6 gas to hold the required skills and knowledge. Caruna’s use, handling and recording of SF6 gas were included in internal audits in 2016.

Use, handling and recording of SF6 gas were included in internal audits in 2016.

In 2016, the total quantity of SF6 gas present in Caruna’s electricity network was 9,610 kg. Approximately a thousand of the 26,000 secondary substations in Caruna’s medium and low voltage networks contained SF6 gas. Caruna’s high-voltage network included a little fewer than 700 SF6-isolated components. The amount of SF6 gas emitted into the atmosphere was 23.29 kg, representing 0.24% of the total quantity of the gas. The emission quantity grew considerably from previous years due to the gas leak caused by damaged equipment at the primary substation in Gumböle, Espoo.

With new contracts on pad-mounted secondary substations, we will begin to use more and more entirely sealed, gas-insulated SF6 medium voltage switchgear in 2017. They are more reliable and safer to use than ever.

Dismantling and recycling of electricity networks

As we replace overhead networks with underground cables, considerable amounts of material needs to be disposed of, such as transformers, iron, conductors, cables, general waste, impregnated wooden poles, glass, porcelain, concrete and copper.

Up to the autumn of 2015, most of the dismantled materials (excluding poles and transformers) were handed over to our contractors, who provided us with regular reports on dismantled material quantities.

In 2016, Kuusakoski processed 4,400 tonnes of the demolition waste from our network projects.

In August 2015, we signed a service contract for the transport and processing of dismantled materials with Kuusakoski Oy. As agreed, Kuusakoski is responsible for the collection of such material from worksites and its further processing. Impregnated poles are an exception to this procedure; Kuusakoski only transports them from worksites to Ekokem’s combustion plants. In the future, we will be able to monitor all materials recycled by Kuusakoski in real time. In 2016, Kuusakoski processed approximately 15%, i.e. 4,400 tonnes, of the demolition waste from our network projects.



In 2016, we dismantled 3,000 tonnes of impregnated poles from our network. Their processing and disposal is subject to tight regulations. A previously common impregnant, CCA, contains toxic and carcinogenic substances and its use on new poles has been banned since 2006. Creosote is another commonly used but carcinogenic impregnant, but Caruna has not used any creosote-treated poles since 2007.

If we notice any loss of poles at the dismantling sites, we report it to the police.

Environmental damage

In our type of operations, a typical example of environmental damage can be leakage of transformer oil into the environment as a result of a damaged transformer. In Finland, over 50% of all transformer damage is caused by lightning.

Oil collectors are installed under building and pad-mounted secondary substations and primary substations, to prevent oil leaking into the environment because of transformer damage. Pole-mounted transformers are susceptible to weather conditions and do not have integral oil collectors. Each pole transformer contains roughly 100 to 200 kg of mineral oil, but usually only a small amount of this would end up in the environment even if the transformer suffers damage.

In 2016, we launched a renovation programme for pole-mounted transformers in groundwater areas with the target of minimising environmental damage.

We clear up any oil leaks as soon as possible and verify the effectiveness of the purification process from soil samples. Information about oil leaks and purification process reports are submitted to the authorities; in this case to the local ELY Centre.

In 2016, our electricity network suffered a total of 34 oil leaks, of which seven were slightly over 100 kg in magnitude. There were no extensive oil leaks or environmental damage caused by oil leaks.

In 2016, we launched a renovation programme for pole-mounted transformers in groundwater areas with the target of minimising the risk of groundwater contamination caused by oil spills. From 2016 to 2018, we will replace all pole-mounted transformers in groundwater areas with pad-mounted secondary substations equipped with oil collectors. During the first year of this project, we removed 250 pole-mounted transformers from groundwater areas. There are still 1,150 such transformers left.

Environmental goals

We intend to keep improving the energy and materials efficiency of our operations, decreasing any adverse effects on the environment and enhancing the recycling of used materials.

During 2017, we aim to significantly cut down the number of pole-mounted transformers in groundwater areas, both as part of our network improvement programme and our renovation programme for pole-mounted transformers in groundwater areas. The number of oil spills will fall as our network improvement programme progresses.

We will strive to raise the recycling rate of dismantled networks.

We will also strive to raise the recycling rate of dismantled networks in collaboration with Kuusakoski. Our target is for Kuusakoski to process the dismantled material in 30% of all our projects in 2017.

Our key environmental goals for 2017 are recorded in the table on corporate responsibility.

In order to achieve our environmental goals and reduce the environmental impacts of our operations, we train both our own employees and our contractors.

Read more about training.

Case: Up to 30,000 bees buzzing around Caruna

Caruna’s bee experiment in the summer of 2016 produced 99 kilograms of honey. More important than the honey harvest, however, is the significance of the bees to the world.

Without bees, there would be few plants and consequently little food for us. The various species of bees have been estimated to pollinate 75–85% of the plant species in the world and without them many plants would not be able to reproduce. Urbanisation and pesticides, for example, have reduced the number of these pollinators, which is already hindering food production in places.

This gave one Caruna employee the idea that Caruna could introduce its own beehives. This would even out Caruna’s carbon footprint and give it a chance to do its bit to sustain our ecosystem.

The buzzing occupants on the roof of Caruna’s office produced almost a hundred kilograms of honey. The harvest was only half of what was expected, but even so it provided plenty of sweetness for the needs of the staff canteen and as presents for the staff. There were two reasons for the poor yield: the rainy summer and the growing season starting two weeks ahead of time, which was evident in honey harvests all over the country.

No bee stings were suffered during harvesting. Although the staff dared not make the acquaintance of the bees buzzing on the roof, the bee experiment received only positive feedback, says Property Manager Antero Lehtonen. The greatest reason for this was the skilful beekeeper Jas Stanislav, who is a board member of the Finnish Beekeepers’ Association and takes care of 40 hives every summer at four bee farms in Espoo and the surrounding area. It is critical to tend to bees regularly to prevent them from forming into swarms and seeking a new place for a hive.

“The bee-keeper changed the honeycombs and fed the bees once a week with a special solution. During the summer, we had three different-tasting and different types of honey harvests, and we sent samples of each to Belgium to be studied in order to find out what plant species they contain,” Lehtonen explains.