The $3.3m battery project at the Forshuvud plant has an output of 5 MW and its storage capacity is 6.2 MW/h.
“Batteries are thought to be used mostly to store energy. Now, however, we will try connecting a battery to a hydropower plant with the idea of improving the plant’s ability to function as regulating power for the Nordic electricity network,” said Martin Lindström, Head of Asset Management Hydro at Fortum.
“The battery’s very quick response time improves the speed and preciseness of the Forshuvud hydropower plant’s regulation, so we are able to provide even better service to grid companies. We hope that this significant innovation helps us to more quickly achieve Sweden’s ambitious targets for renewable energy use and create a cleaner world.”
He added that with wind power expected to increase significantly, the electricity network must be more flexible in order to maintain a consistent balance between production and consumption and maintaining the correct frequency of the grid is necessary for the operation of the electricity system.
“Many power plants ramp their power output up or down to keep the network’s frequency at 50 Hz. Balancing may be needed very quickly, even in a matter of a few seconds.
“The new battery will help to keep the frequency in balance, and the Forshuvud power plant will recharge the battery with renewable hydropower. The new battery will adjust the balance quickly.”
Today the Swedish electricity market is kept in balance mainly with hydropower, which can provide balancing flexibly at different time periods, from a few seconds to several months. However, quick balancing causes significant wear to the hydropower plant’s turbines. Fortum says this is why the use of batteries is expected to become more common in an energy system that requires increasingly faster balancing.
Over the past two years, Fortum has tested a similar concept at a combined heat and power plant in Järvenpää in its native Finland. The company said the concept “has proven to be functional and the battery solution to be taken into use in Forshuvud is based on the experiences gained in Järvenpää”.
Tatu Kulla of Fortum Trading and Asset Optimisation said: “In Järvenpää we determined that the concept works. Now we want to test a bigger battery and improve the characteristics of hydropower plants.
“The best resources have been developing the concept, and now we are ready to move to the next level. The Swedish project is a natural next step in the use of batteries to balance electricity networks.”
The construction work will start early next year with the aim is to have the battery operational in the following months.