Anergy networks with water circulation are an efficient solution for the supply of urban heating services, but require a bulky and expensive infrastructure with higher energy consumption. Replacing water with CO2 enables a more compact solution with lower energy consumption, less infrastructure and lower costs that could transform the national urban heat system. The Energypolis Campus offers an ideal opportunity to demonstrate this technological innovation. HES-SO Valais and EPFL Valais are working with local industries to build a CO2 network of around 400 kW to cover a significant part of the cooling and heating needs of the three buildings on the site. This installation will make it possible to fully demonstrate the validity, reliability and operational safety of the concept, its energy and cost performance and to test various technological options.