This lecture explains the operation of the EPFL Thermal Plant (CCT) following the renovation of its heating and cooling facilities on the Lausanne campus. The EPFL has been a pioneer in using energy resources, utilizing lake water for cooling since the 1970s and for heating since the 1980s. The recent renovation involved installing 4 heat pumps with a total power of 24 MW, sufficient to heat all campus buildings. The plant operates in three stages: water pumping from the lake, heat production using ammonia-based heat pumps, and water distribution through the campus. Additionally, the lecture covers the integration of a 1000 m² data center within the plant, hosting up to 200 computer racks and utilizing the heat generated by the racks to improve heat pump efficiency. Various energy-saving initiatives at EPFL, including sustainable food, reduced business travel, and promoting eco-friendly commuting, are also discussed.