CH-24-C126 - Waste Heat Recovery from Data Center Cooling System for District Heating

Background: There is a global increase in interest regarding the utilization of unutilized energy to achieve carbon neutrality. Data centers, known for their high energy consumption and year-round cooling requirements, produce a significant amount of heat that requires constant removal. Approximately 95-100% of the power consumed in data centers is converted into heat, a substantial portion of which is discarded as waste heat. Purpose: To effectively recover waste heat in data centers, there must be continuous demand and economic feasibility. In the case of data centers, heat is released from the condenser (cooling tower) to the outside. However, the collected heat, typically around 35°C(95°F) , is not suitable for space heating purposes. This study proposes the recovery of waste heat from data centers as a pre-heating source for domestic hot water systems, which have a year-round heating demand, and aims to assess its applicability. Method: We analyzed the potential waste heat from the annual cooling system operation of a large-scale 30 MW data center. Our proposed system involves installing a heat exchanger in the city water supply line of a nearby demand source, such as an apartment complex, to pre-heat the water by at least 5°C(41°F) and recover approximately 5-10°C(41-50°F) of waste heat from the cooling system. Results: Based on the actual water heating usage of approximately 27,000 units in a nearby apartment complex, we calculated the domestic hot water profile, considering the intermediate, summer, and winter seasons. We analyzed the energy savings and costs associated with the waste heat recovery from the data center, revealing a reduction in energy consumption by approximately 12% compared to the existing district heating system.