Techno-economic analysis of a solar thermal-boosted organic Rankine cycle system for data center heat recovery

Abstract

The rapid growth of digital advancements and computing has led to a significant increase in the quantity and capacity of data centers (DCs). DCs consume substantial electricity, resulting in a high carbon footprint and environmental impact. A significant portion of this energy is dissipated as waste heat through DC cooling. Studies have shown the potential benefits of integrating organic Rankine cycle (ORC)-based waste heat recovery (WHR); however, these systems face the challenge of lower ORC efficiencies due to the ultra-low temperature of DC waste heat. In this study, we introduce and investigate a novel solar thermal-boosted ORC system for WHR in DCs using flat plate collectors. Solar collectors boost WHR temperature, thereby enhancing efficiency and output. Techno-economic modeling and simulations are conducted with case studies for two U.S. locations with the most DCs. Solar boosting increases ORC efficiency by over 8 % during peak solar hours, and the annual ORC output is increased by 60 % in Ashburn and 81 % in Los Angeles. Additionally, it reduces the levelized cost of electricity by 5.5 % in Ashburn and 16.5 % in Los Angeles. Sensitivity analysis shows that the solar boosting offers even greater economic advantages at lower WHR temperatures, reinforcing its benefits over conventional systems.