Finnish energy company Fortum is launching the Nordic countries’ biggest energy storage pilot project.

The €2 million ($2.2 million) project will incorporate megawatt-scale lithium-ion (li-ion) battery storage technology from French company Saft.

Saft’s li-ion containerized battery system with a nominal output of 2 MW and 1 MWh of energy capacity will be installed at Fortum’s Suomenoja combined heat and power (CHP) plant (pictured), in Finland’s second largest city Espoo.

The battery project is an extension of a Fortum experiment started in March in which a virtual power plant based on demand flexibility is being built together with customers.

The capacity of this plant will be offered to national grid company Fingrid to maintain a continuous power balance in the electricity system.

Planning for the Suomenoja battery project is underway and the aim is to start installation work in September with testing of electricity storage due to begin in October.

Fortum will receive a 30% energy investment subsidy from Finland’s Ministry of Employment and the Economy towards the cost of the project.

Fortum said that the Suomenoja plant is ‘an ideal test environment for the pilot because the plant already has in use an industrial-scale heat pump station, which produces about 300,000 MWh – as much as 15% of Espoo’s district heat demand’.

One of Finland’s biggest thermal batteries is also currently under construction at the plant. It can store about 800 MWh of thermal energy – the equivalent to the heat consumption of about 13,000 single-family homes per day.