Potential and climate effects of large-scale rooftop photovoltaic energy deployment in northwest China’s capital cities

China's pursuit of photovoltaic (PV) power, particularly rooftop installations, addresses energy and ecological challenges, aiming to reduce basic energy consumption by 50% by 2030. The northwest region, with its solar potential, is a focal point for distributed PV growth, which has already exceeded 50% of the energy mix by 2021. This study assesses the rooftop PV potential in five northwestern capitals, finding favorable conditions such as ample space, dense populations, and high sunlight exposure. Cities like Yinchuan and Xining are highlighted for their high projected annual PV yields. Although there is a negative correlation between surface temperature and vegetation coverage, the Weather Research and Forecasting (WRF) numerical simulation found that large-scale deployment of rooftop photovoltaics will not have a significant impact on the vegetation ecology of the area. The research underscores the significant role of rooftop PV in achieving China's energy and climate goals in its northwestern urban centers.