Energy and exergy analysis of a renewable ultra-low temperature heating and cooling network with a central ground source heat pump

The decarbonization of thermal energy in cities is essential for achieving climate neutrality goals. This paper investigates the benefits of a strategic transition from a reference tri-generation district heating and cooling network to a novel low-temperature configuration based on the integration between heat pumps and wind technologies. Heating and cooling performances of the two configurations are compared in a mixed-use neighborhood in Denver, Colorado through dynamic hourly simulations over a full reference year. The baseline system is based on a natural gas-fired combining heat and power unit with absorption cooling, while the alternative configuration adopts an electrified approach based on a central ground-source heat pump, decentralized water-to-water heat pumps, and on-site wind power generation. The two configurations have been compared focusing on energy, exergy and environmental performance. The renewable configuration reduces primary energy use by 25% and CO2 emissions by 22%, also improving exergy efficiency (from 0.37 to 0.46) due to improved energy conversion process and on-site renewable exploitation. These results demonstrate the viability of ultra-low temperature district networks powered by renewable electricity and heat pump technology as a promising and resilient solution for low-carbon urban infrastructures in a real context.