Energy Storage

Kuopion Energia strores heat in the district heating battery 

The Kuopio Energia Haapaniemi plant produces heat and electricity. Electricity is generated as a byproduct of heat, and in order to keep the efficiency of the power plant good, electricity is only produced according to what is needed to generate heat for the customers of the district heating network. 

Kuopion Energia built a district heating battery next to the Haapaniemi power plant in 2020. In practice, it is a large water storage, where the heat produced by the power plant can be stored and transferred to the district heating network as needed.

The district heating battery is 15,000 cubic meters in size and, on average, it continuously stores around 13,500 cubic meters of water at 75-98 degrees, and this amount corresponds to the current amount of water in Kuopio’s district heating network. The water returns to the tank from the district heating network at around 40 degrees. The water flow into the tank is a maximum of 500 liters per second. The storage can hold 800 megawatt-hours of energy, and the charging and discharging power of the battery is 85 megawatts.

The district heating battery brings flexibility to the district heating system and increases operational reliability. When heat can be stored in a district heating battery, it is possible to schedule the sale of electricity generated as a byproduct of district heating to the market at a time when the market price of electricity is as good as possible. A better electricity price makes it possible to keep the price of district heating competitive for customers.

Further info in Finnish: 

Kaukolämpöakku tuottanut miljoonan jo ensimmäisenä vuonna – 

Basic information 
 Implementation year: 2020  
Implementor: Kuopion Energia 
EUR 5.8 million
Benefits achieved 
In less than a year, the benefit was approximately one million euros.
Payback time 5 – 7 years.