An accumulator the size of a shipping container stores energy to cover incidents such as large-scale network faults. It will provide electricity to hundreds of households in the area until the network can be repaired. This is a trial to study methods for storing electricity and to seek new ways to improve the quality of supply in the region, as well as flexibility when required. The trial is implemented together with Fortum.
The electricity storage in Inkoo serves both locally and the entire system
Electricity storages are planned in areas such as Stubböle in Inkoo, where the service life of overhead lines continues. Overhead lines would therefore not need to be dismantled to ensure security of supply. When Caruna does not need the accumulators to repair a power outage caused by a maintenance or fault situation, Fortum will use the accumulators in the control electricity market to balance the national electricity system.
"Accumulators can also be a solution for areas where the need for electricity suddenly increases and the network needs to be strengthened, for example as the number of electric buses increases," says Caruna's Innovation Project Manager Markus Talka.
Even if electricity supply to the accumulators were cut off, they can electrify nearby homes, summer cottages and shops for several hours. The area of influence of the accumulator located next to Road 51 extends from about Stubböle to the island of Vormö.
Smoother flow and fewer outages
Electricity production and consumption must be balanced at all times. As the number of solar and wind power producers increases, more flexibility is needed, since a lot of energy enters the network at once when the sun is scorching or the wind is blowing. With the help of an accumulator, energy can be momentarily stored. It allows extremely fast adaptation to the needs of the power system.
"We want to invest in electricity storages, because with accumulators, we can balance the transmission network frequency even better. When electricity flows more evenly, more renewable energy can be stored in the network," says Business Development Manager Ilari Alaperä, Fortum.
An accumulator can store 1,028 kWh of energy, which would move an electric car back and forth from Helsinki to Berlin or heat a terraced three-room dwelling for about six months.
What does an electricity storage contain?
The electricity storage supplied by Alfen was built in the Netherlands, but the smartest part of the accumulator, the control system, was made in Vaasa. The substation connected to the accumulator was manufactured by Alfen's subsidiary, which operates in Pietarsaari.
The accumulator of an electricity storage consists of minerals, the responsible mining of which has been questioned in e.g. discussions on electric cars. Samsung SDI, the supplier of the electricity storage accumulator, raises the issue of control related to cobalt and other minerals in its responsibility report. Responsible mining respects human rights and avoids child labour, health and environmental hazards as well as corruption.