Lahti Energy is currently planning district cooling for new residential areas, the first of which will be the Ranta-Kartano residential area being constructed in the city centre. Thanks to various reports and research studies, the use of groundwater in cooling, which began a couple of years ago, has been shown to be a workable option. Since 2000, Lahti’s Sibelius Hall as been the only property connected to Lahti’s district cooling network. The city’s location on the Salpausselkä ridge, on top of significant ground water reserves, is now making district heating a profitable business. With groundwater, the centrally generated cold carbon dioxide emissions are significantly smaller than those of other condensation systems, and the energy rating of properties using district cooling is also better.