Nacka municipality commissioned its first battery storage in September, at Sigfridsborg school and sports hall in Älta. The system is meant to provide environmentally friendly backup power in a crisis and revenue on all other days. According to Mats Gerdau, chair of the municipal executive board, Nacka is one of the first municipalities in Stockholm County with this solution.
How it works
The battery storage is connected to solar panels on the roof, which allow the school to function as a self-sufficient island during a longer power cut. Thanks to earlier investments in solar panels, the batteries can be charged with renewable solar energy. During an outage the storage can run the school’s operations for 4 to 48 hours, depending on season and activity. If the batteries run out, mobile backup power can be connected. The storage is now ready for service around the clock, seven days a week.
| Item | Figure |
|---|---|
| Storage capacity | 700 kWh |
| Equivalent | about 40,000 fully charged mobile phones |
| Run time during an outage | 4–48 hours |
Why Sigfridsborg
Sigfridsborg school was chosen first because it has a production kitchen and is an emergency support point. It is one of five such points in Nacka, together with Fisksätra multihall, Dieselverkstaden in Sickla, Myrsjö sports hall and school, and Nacka city hall. At these points residents can get help during major disruptions when home preparedness is not enough. With battery storage, the point can keep running and, for example, cook food for many people even during a longer power cut. The public can also visit to get information, charge phones, collect drinking water or warm up. In a more serious crisis, overnight accommodation will also be available. The support points are to be equipped with communication equipment, phone chargers, first-aid supplies, torches, water and blankets.
Funding and everyday use
The battery storage is a joint project between Nacka municipality and Nacka Energi Försäljning. It received investment support under Robust kommun, a programme of the Swedish Energy Agency. Outside a crisis, the storage helps stabilise the grid and lets the municipality cut power peaks by selling electricity when the price is high and buying when it is lower.
What happens next
Johan Hellberg of Nacka Energi Försäljning says that in a few months an evaluation can examine which of the other emergency support points is next in line for battery storage. More broadly, Nacka has a goal of being climate positive and circular by 2040.