Techno-economic assessment of the deployment potential of solar district heating in high solar radiation plateau regions

Abstract

Solar district heating is a promising low-carbon heating option for high-altitude Xizang, yet county-level assessment methods that simultaneously account for collector-field siting constraints and techno-economic performance remain lacking. This study develops an integrated county-level assessment framework for solar district heating potential and introduces two complementary indicators: the maximum heating coverage radius ( R max ) to characterize effective heating reach, and the heating cost performance (HCP) to evaluate cost-effectiveness. LCOH is additionally evaluated for the three representative districts. The framework couples geospatial screening of collector-field sites with meteorological conditions, heating-demand characteristics, and system techno-economic parameters. It is first examined through case studies in three representative county-level units in Xizang-Sangzhuzi, Nedong, and Bayi-and is then extended to 74 county-level units to quantify the regional pattern of solar district heating potential. Case studies indicate that the ranking of R max is Sangzhuzi > Nedong > Bayi, whereas the ranking of HCP is Nedong > Sangzhuzi > Bayi, demonstrating that stronger physical heating reach does not always imply higher economic efficiency. LCOH ranges from 0.4844 to 0.4898 CNY/kWh, with a difference of only approximately 1.1% among the three representative districts. At the regional scale, Ngari exhibits the highest coverage potential, with Rutog County reaching an R max of 18.79 km, while Shigatse shows the highest economic potential and Nyalam County records the highest HCP. Overall, abundant land and strong solar resources favor larger heating reach, whereas relatively concentrated demand and shorter heat-supply distance are more critical for economic viability. This study provides a quantitative basis for regional screening, project siting, and differentiated renewable heating pathways in plateau regions.