Energy Efficiency in Data Centers: Solar Thermal-Boosted Organic Rankine Cycle for Waste Heat Utilization

The rapid expansion of digital infrastructure has led to an increase in the number and capacity of data centers, which are now significant sources of low-grade waste heat. Traditionally, the challenge of utilizing this waste heat stems from its ultra-low temperature, limiting the effectiveness of an Organic Rankine Cycle (ORC) based recovery system. This study introduces a novel approach to waste heat recovery by integrating flat plate solar thermal collectors (FPCs) with an ORC system specifically designed for data centers. By utilizing FPCs to preheat the waste heat from data center racks, the ORC’s thermal efficiency and overall system performance are significantly improved. A techno-economic analysis, based on a case study of Ashburn, VA, the region with the highest concentration of data centers in the U.S., demonstrates that solar thermal boosting nearly doubles power output, increases ORC efficiency by over 8% during peak hours, and reduces the investment per unit of electricity by 19.09%. These findings highlight the economic and environmental potential of solar-boosted ORC systems in transforming the energy efficiency of data centers.