With a smart heating and cooling system and renewable energy, the city district of Västra Hamnen (Western Harbor), in Malmö, Sweden has established itself as the first carbon-neutral neighborhood in Europe, says Malmö mayor Ilmar Reepalu.

Västra Hamnen, also known as the City of Tomorrow, was transformed from a former shipyard in 2001 and is now home to 4,000 people.

The district uses an aquifer thermal energy storage system to store water collected during the summer 70 meters (230 feet) underground and pump it up with wind energy to heat the homes during the winter. The chilled water is then reused to cool buildings in the summer.

“There’s no need for air-conditioners in the district,” Reepalu proudly told the audience