Biggest heat accumulator in Estonia will reduce gas usage and stabilize prices


We had the pleasure of opening Estonia’s biggest heat accumulator in Tartu, which stands at 45 meters high, has a 17-meter diameter, and has a capacity of around 10,000 cubic meters. The aim is to reduce the use of gas in district heating and stabilize prices.

Heat consumption fluctuates throughout the day. In the fall and spring, for instance, temperatures are generally warmer during the day, resulting in less heat consumption, while at night, rooms become colder.

“The logic is that if there’s surplus heat during the day, it’s stored as hot water. Then at night, when more heat is required, it’s retrieved from that storage and fed into the district heating network,” said Margo Külaots, country manager of Estonia.

Without the storage facility, boilers, which often run on gas, remain switched on during the cold hours of the night. Külaots pointed out that gas is not only expensive but also an imported fossil fuel.

The storage facility allows Gren to use wood chips as an alternative to gas. Külaots mentioned that reducing gas usage means the company will cut its CO2 emissions by 2,000 tonnes a year.“

In addition, boilers don’t need to be constantly switched on and off to match specific hours. Frequently switching boilers on and off is inefficient and can lead to breakdowns,” he added.

The new system will cut the annual gas consumption by an amount equivalent to that used by 18 large apartment blocks.

Until now, no other similar facilities have been installed in Estonia. Külaots believes this might be because, before the previous year, gas was cheaper, and district heaters were often used to toggle boilers during peak times. However, the primary motivation for building new storage facilities stems from recent advancements in construction and insulation technology, allowing for higher standards.

For district heating customers, the impact on their bills will be minimal, Külaots explained. “It will certainly help stabilize prices. If we consume less gas and replace it with wood chips, given that gas is pricier, it will have a downward effect on prices. However, the main benefit will likely be an improved security of supply,” he concluded.