Rooftop solar could supply two-thirds of world’s energy needs

New research that maps the global rooftop area says that rooftop PV could substantially contribute to reducing global temperatures by up to 0.13 °C before 2050. The estimated 286,000km² of rooftops globally offer enough space to “provide the single largest contribution to [climate change] mitigation in 2050”.

The research, in Nature Climate Change, integrates geospatial data mining and artificial intelligence techniques to estimate the global rooftop area. It also compares the cost of rooftop solar with nuclear energy, finding that while rooftop solar is £30-50 per megawatt hour, new nuclear projects can cost significantly more, between £100 and £150.

In terms of its potential around the globe, rooftop PV presents East Asia with a huge opportunity to shift away from reliance on fossil fuels by using its vast expanses of rooves, particularly in China and India. Like East Asia, North America and Europe have dense urban areas with strong potential for rooftop solar, and despite comparatively less sun, they could provide 25% of the global total. Despite Africa having the highest solar energy potential, the continent accounts for just 1% of global rooftop PV installations, highlighting the continent’s huge potential and the need for increased investment.

Read the full paper

This article is a summary of a research paper:

Worldwide rooftop photovoltaic electricity generation may mitigate global warming

Authors: Zhixin Zhang, Zhen Qian, Min Chen, Rui Zhu, Fan Zhang, Teng Zhong, Jian Lin, Liang Ning, Wei Xie, Felix Creutzig, Wenjun Tang, Laibao Liu, Jiachuan Yang, Ye Pu, 
Wenjia Cai, Yingxia Pu, Deer Liu, Hui Yang, Hongjun Su, Mingyue Lu, Fei Li, Xufeng Cui, Zhiwei Xie, Tianyu Sheng, Kai Zhang, Paolo Santi, Lixin Tian, Guonian Lü & 
Jinyue Yan