Chinese scientists and their international counterparts have published an assessment of the carbon mitigation potential of rooftop photovoltaics (RPVs) in China, noting that they could be offsetting about 2.72 billion tonnes CO2 in 2030.

The rooftop photovoltaic is a solar system with electricity-generating solar panels installed on a building's roof. According to the study, published recently in the journal Nature Communications, RPVs are important in achieving energy transition and climate goals, especially in cities with high building density and energy consumption. 

Estimating RPV carbon mitigation potential at the city level of an entire large country is challenging given the difficulties in assessing a rooftop area.

Researchers from Nanjing Normal University and other institutions in China, as well as those from the United States and Singapore, used multi-source geospatial data and machine learning regression to identify a rooftop area of nearly 66,000 square kilometers for 354 Chinese cities in 2020, representing about 3.63 billion tonnes of CO2 mitigation.

Considering urban land expansion and power mix transformation, the researchers estimated a potential CO2 mitigation of about 2.72 to 3.63 billion tonnes in 2030, when China plans to reach its carbon peak.

The study also suggested that it is necessary to further explore how to improve the flexibility of RPV energy production, such as combining RPVs with energy storage technology to achieve continuous power supply at night and reduce any fluctuation on the power grid.

(With input from Xinhua.)

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