Assessing the applicability of 5th-generation district heating and cooling for energy-efficient retrofits in a net zero energy campus

Abstract

This study evaluated the techno-economic and environmental performance of 5th-generation district heating and cooling systems across 13 cases. Key performance indicators included the levelized cost of heat, seasonal coefficient of performance, primary energy consumption, and CO2 emissions. The results showed that the seasonal coefficient of performance values for the 5th-generation district heating and cooling system cases ranged from 4.5 to 4.85, reflecting higher efficiency compared to conventional air-source heat pumps. It leads to the reduction of primary energy consumption and CO2 emissions by up to 45%. Economic performance improved particularly in cases with a larger proportion of data-center cooling load. INT-1 achieved the lowest LCOH of 0.105 $/kWh, which was 9.5% lower than that of the Base case. It also found that the cases with decreased reliance on external heat sources and increased utilization of waste heat recovery also showed lower system capacity requirements and investment costs. This study concluded that load composition optimization and efficient waste heat utilization are key design variables for enhancing the performance and economic viability of 5th-generation district heating and cooling systems.