Introduction
The new district cooling system that will be installed in ca. 22 pilot buildings will use residual heat for producing water, which will be supplied through the existing district heating network. More specifically, this system will be based on a heat pump that, installed to return the flow of the district cooling system, will produce heat for the district heating system by using residual heat from cooling.

The district cooling system will use free solar energy from PV panels to cover a part of the cooling system’s energy demand. As such, the use of fossil electric energy for producing hot water with electric boilers will be replaced with residual heat and electricity produced by PV panels. The solution will meet consumer demands for thermal indoor comfort and domestic hot water while retaining high energy efficiency and share of renewable energy. The plant is located next to river Emajõgi, allowing to use river-cooled chillers that are a part of the high-performance production solution. Water from the river is used for free cooling from October to April.

At the moment, Tartu’s district cooling network is 1.6 kilometers long. The district cooling project will decrease the need of electricity by 70% annually compared to local cooling solutions. The decrease in electricity use will benefit the environment by reducing CO2 emissions by 70%, i.e. 6,000 tons a year. The district cooling plan reduces the use of primary energy by more than three times.