Estimating environmental impact of rooftop photovoltaic from the perspective of thermal power transmission

Abstract

The development of rooftop PV (RPV) plays a significant role in addressing the dual challenges of environmental air pollution and climate change, as RPV-generated electricity is an important substitute of traditional coal-fired power and can promote energy transition. Besides, RPV power generation, due to its self-consumption nature by the users, will not only reduce the local supply of coal-fired power, but also reduce the coal-fired power transmitted from other regions, ultimately leading to the spatial spillover effect of RPV environmental impact. Therefore, this study aims to examine the inter-provincial transmission of RPV environmental mitigation potential and economic benefits in China. Based on the revised rooftop vector data, we estimate that RPV deployment in the built-up and densely populated eastern region will reduce the emission of 45–161, 0.01–0.03 and 0.01–0.03 million tons (MT) yr⁻¹ for carbon, SO₂ and NOx in the western China, representing up to 15 %, 14 %, and 11 % of the western provinces' emission from the power and heat sector in 2020, respectively. Correspondingly, the environmental benefits of emission reduction in eastern region show obvious spillover effect (16 %), which lead to additional net benefits of 667–996 billion yuan for the western provinces. Integrating the environmental benefits as a subsidy into power benefits reveals that this type of subsidy yields higher benefits than current policies. Therefore, we provide valuable insights into targeted RPV deployment, promoting environmental efficiency and economic benefits. This new perspective on the spatial spillover effects of renewable energy can also be applied to other countries.