More flexible storage needed

The Nordic region benefits from large hydro reservoirs that provide excellent and cost-effective energy storage options, which are already being efficiently utilised.

Meeting growing future flexibility needs with a changing energy mix will require supplementing hydro reservoirs with batteries or hydrogen-based fuels.

While the use of battery storage is on the rise, the current installed capacity remains relatively insignificant compared to hydro storage. To fully harness the potential of renewable energy, significant investments in battery and hydrogen storage technologies are essential. This will ensure a resilient and sustainable energy system capable of meeting the region's ambitious climate goals.

Important roles for batteries in the Nordics

Despite an extensive hydro storage capacity in the Nordic region, batteries can still play an important role in the electricity system for several reasons:

Fast response times: Batteries can respond almost instantly to fluctuations in electricity demand or supply, making them ideal for short-term grid balancing and frequency regulation, where quick adjustments are critical.
Distributed energy storage: Unlike centralised hydro reservoirs, batteries can be deployed closer to consumers, at homes, businesses, or within local grids. This helps improve energy reliability and reduces transmission losses.
Support for intermittent renewables: With the increasing share of solar and wind power in the Nordic energy mix, batteries can store excess energy generated during peak production times and release it when renewable generation is low, further enhancing grid stability.
Peak load shaving: Batteries can help reduce peak electricity demand by storing energy during off-peak hours and supplying it during high-demand periods, alleviating pressure on the grid and minimising the need for additional power generation.

The Nordic countries are expected to have almost 1800 MW of installed battery capacity by 2030, not including batteries in electric vehicles.

Figure 06.3: Expected battery capacity in the Nordics by 2030, not including batteries in electric vehicles. Megawatts measure the rate at which energy is injected into or drawn from the grid at any given moment.

Data source: ENTSO-E ERAA2023 and Analyseforudsætninger til Energinet

Battery storage globally

According to the Announced Pledges Scenario* from the International Energy Agency (IEA) the battery storage capacity worldwide will increase from approximately 1% of the total power capacity as of 2023 to 6% and 12% in 2030 and 2050, respectively. This would mean that the total battery storage capacity would increase from about 90 GW to 4400 GW globally.

Figure 06.1: Battery storage capacity, based on announced pledges, IEA.

Figure 06.2: Share of battery storage capacity out of total power capacity, IEA.

* The Announced Pledges Scenario explores the outcomes if all national energy and climate commitments, including net zero targets, are fully achieved on schedule.

Energy storage

Finland, Norway and Sweden have a substantial energy storage capacity of approximately 125 TWh, thanks to their large hydro reservoirs. To put the Nordic hydro storages into perspective, the energy storage capacity of 100 million electric cars is approximately 5 TWh (assuming 50 kWh per car).

This vast storage is essential for balancing the fluctuations in renewable energy generation.

With existing interconnections to the UK, Germany, the Netherlands, Poland, and the Baltics, the Nordic region already serves as a key energy storage provider for the rest of Europe.

Many Nordic hydropower plants are upgrading their control systems to improve its responsiveness. By installing advanced automation and digital monitoring systems, operators can better control water flow and turbine operations.

Figure 06.4: Energy storage capacity volumes in Europe compared to Denmark, Norway, Seden and Finland. Terawatt-hours measure the total amount of energy stored or consumed over a period of time.

Data source: ENTSO-E ERAA2023 and Analyseforudsætninger til Energinet

In the spotlight:
Battery storage cases

Battery energy storage is essential for the Nordic region's energy transition, enhancing grid stability and reliability. Batteries can provide crucial backup power, regulate grid frequency, and support energy markets, demonstrating their importance in creating a resilient and sustainable energy infrastructure. As the Nordics continue to invest in battery storage, they pave the way for a secure and efficient energy future.

Denmark
The energy company EWII is locating a 30 MW/43 MWh battery energy storage system next to the high voltage transformer station at Hasle, Bornholm. For a start, the battery will be supplying ancillary services to Energinet, but the battery can also supply Bornholm with electricity for one hour, in the case the island is isolated because of cable failure.

Finland
OX2 has sold its 50MW/110MWh battery energy storage project in Uusnivala, Finland, to the L&G NTR Clean Power Fund. The project will help regulate grid frequency and stability and participate in energy arbitrage in wholesale markets.

Sweden
The Elektra Energy Storage Project, Sweden’s largest battery storage project, is now fully operational. Located in Landskrona, southern Sweden, the project will provide ancillary services to help balance the grid for Landskrona Energi.

Source: Green Power Denmark, OX2, RES group Sweden
Photo: Axpo, RES group Sweden

In the spotlight:
Largest cavern heat storage in the world

Vantaa Energy in Finland started the construction of the largest underground thermal energy storage in the world. It will have a volume of 1.1 million m3 and capacity of 90 GWh, approximately 5% of Vantaa's annual DH demand.

The deepest section of the storage will be 140m below the ground level and high hydrostatic pressure enables very high storage temperatures up to 140 degrees Celsius.

The storage is charged with excess heat from a nearby waste incineration plant and with electric boilers during low price hours in the Finnish market area. Electric boilers with heat storage will likely become a new major source of flexibility for the electricity sector.

The discharge power of the storage will be 200 MW, which is roughly half of the winter base load of the whole city of Vantaa. This allows more flexible operation of the district heating grid and helps avoid start-ups of fossil units.

Storage investments in general require cheap charging and enough full cycles throughout the year to be profitable. Vantaan Energia is planning to achieve this through multiple charging methods, increased flexibility in operation, and varying power prices in Finland.

The estimated cost is 200 million euros and the construction is planned to start in spring 2025.

Source: Vantaan Energia
Photo: Vantaan Energia