The paper introduces a novel strategy for optimizing waste heat recovery in data centers (DHs). With this strategy, waste heat from a data center is first upgraded to 60-90 oC in a water-to-water heat hump plant and then introduced to local district heating (DH) network to provide heating for nearly buildings. At the same time, the cooling product from the heat pump plant is utilized as a free byproduct (energy company pays electricity for heat pumps) to cool the data center. Both energy company and data center involve in investing heat pumps. This strategy can significantly cut power cost and CO2 emission for energy company and data center (cooling is free). The potential is large for this strategy because, event in summer, heating demand is far more than total IT capacity of data centers in Finland. Furthermore, this strategy is applicable for all kinds of existing data center cooling systems. The paper also describes a real green data center (over 1 MW IT load) implemented by this novel strategy.
Keywords Data center, heat recovery, waste heat reuse, heat pump, district heating network, CO2 emission