Enhancing energy–climate–economy sustainability in coastal cities through integration of seawater and solar energy

Abstract

Coastal cities consume 60% of global energy, and seawater-cooled district cooling systems (SWDCS) and rooftop solar photovoltaic systems (SPVS) are effective technologies for utilizing the abundant renewable resources of seawater and solar energy in coastal regions. However, the high investment required for SWDCS and intermittent output from SPVS can limit the quantification of their energy-saving potentials and their large-scale implementation. This study developed GIS data-based methods to map the spatial distribution of carbon abatement costs and a carbon price-based decision tool for achieving optimal co-benefits of integrating SWDCS and SPVS in Hong Kong (the Special Administrative Region of China), Jeddah (Saudi Arabia), and Miami (the USA). These three cities were selected to account for uncertainties associated with different climates and urban characteristics. The carbon abatement costs of SWDCS vary significantly across and between cities, and the carbon mitigation opportunities of SWDCS are much greater than those of SPVS. Integrating the two systems with a carbon price of 250–350 USD/tCO2e would balance carbon mitigation and economic performance to a relatively optimal state in the three cities. This study provides a tailored approach for mapping carbon abatement costs and understanding the co-effects of integrating SWDCS and SPVS in coastal cities, contributing valuable insights into enhancing energy resilience in coastal urban areas with economic and climatic benefits.