News / 2.6.2015

Largest electricity storage facility in the Nordic countries to be built in Helsinki

The electricity storage facility will be built in Suvilahti, close to Helen’s solar power plant which is largest of its kind in Finland. In the pilot project, new opportunities offered by a megawatt-scale electricity storage facility will be tested: flexible intermediate storage of electricity and new business models that can be developed by storing electricity.

Helen is the first company in the Nordic electricity market to connect a megawatt-scale lithium battery storage facility to the electricity grid. The significance of energy storage increases when renewable energy sources become more common. Solar panels and wind turbines are built all the time. Electricity can be stored in good weather conditions when there is a lot of production but only little demand.

The Suvilahti electricity storage facility will consist of about 15,000 lithium-ion battery cells, which can temporarily store the electricity generated by Helen’s solar power plants in Suvilahti (340 kWp) and in Kivikko (under construction, 850 kWp). The rated power output of the electricity storage facility will be 1.2 megawatts and its energy capacity 600 kWh.

There is no corresponding electricity storage facility in Finland or even in the other Nordic countries.

– It will be the largest battery-operated electricity storage facility in the Nordic countries and a key pilot project, says Juha Karppinen of Helen. – The project’s greatest innovation is in the way the facility will be operated and controlled. We will study and test when it is worth charging and discharging the battery and who is prepared to pay for is at any given time and according to which logic, Karppinen explains.

The facility will be part of the developing smart grid of the future. Its function is to balance the electricity supply. The benefits of this battery-operated electricity storage facility are its instant start-up and easy controls.

With intermediate storage of electricity, supply and demand can be adjusted more flexibly, and the electricity storage facility will also stabilise the electricity grid. As an electricity reserve, it will support the grid in fault situations and take part in the compensation of reactive power, i.e. maintain the grid voltage.

The investment cost of the facility is about two million euros, and it will receive 30 per cent of aid from the Ministry of Employment and the Economy.

Helen’s partners in the pilot project are Helen Sähköverkko and the national transmission system operator Fingrid. The battery technology will be delivered by Landis+Gyr in partnership with Toshiba. The electricity storage facility will be part of the smart energy system in Kalasatama.

– Energy storage will play a key role in the implementation of smart grids. Together with Toshiba, we will deliver the latest battery technology, which will advance the entire energy sector, not only in Finland but also on the international scale, says Ari Tolonen of Landis+Gyr.

Helen is a forerunner in energy storage

Energy storage is part of Helen’s concept of best city energy in the world. Helen is a forerunner in energy storage on the global scale. Heat has been stored for some time in district heat storage facilities in Vuosaari and Salmisaari and cold has been stored in the district cooling storage facility in Pasila. The new cooling water storage facility in the Esplanade Park was commissioned in the spring.

Energy storage enables flexible use of energy in various demand situations. Storage can also ensure the availability of energy. The stores aim to utilise the most efficient and economical production methods as effectively as possible.


• An electricity storage facility operates in the same way as an ordinary mobile phone or laptop charger, and its capacity corresponds to about 100,000 mobile phone chargers
• The output of the entire facility: 1.2 megawatts
• Energy capacity 600 kWh
• Size of the facility: 12 x 2 x 2 metres
• No need for permanent foundations, built on a base
• To be located in connection with the Suvilahti solar power plant
• The battery will be assembled in Italy at the turn of the year and it will be installed in March 2016. It will be commissioned in spring 2016.
• Investment cost is about EUR 2 million