Solar energy is on track to become the world's leading renewable energy source. Research from McGill University provides a more precise idea of the land area needed for this growth and shows that smart choices could reduce the land footprint associated with harnessing this resource.
"If current trends continue, solar photovoltaic energy will be the largest source of renewable energy in the world by 2029. But we lack the data and tools needed to understand the land impact of such growth," says Sarah Marie Jordaan, associate professor in the Department of Civil Engineering at McGill University and director of the Energy Technology and Policy Assessment (ETAPA) research group. The researcher also works at the Trottier Institute for Sustainability in Engineering and Design.
Two complementary studies led by Professor Jordaan's lab fill this gap. They address, from regional and global perspectives, how we can develop the solar sector while minimizing as much as possible the pressures on land, which are limited and often overlooked resources.
In the first study, published in
Communications Earth & Environment, the team used artificial intelligence to measure the land footprint of large solar installations in the western United States.
"Using computer vision and deep learning techniques, we analyzed high-resolution aerial images to quantify the area occupied by 719 photovoltaic solar projects in the western United States," explains Sarah Marie Jordaan.
The study provides a uniform and reproducible method to measure the area used by large solar projects and assess the land impacts of the rapid growth in the solar energy sector. It also highlights the influence of technical choices and location on efficient land use, with sunnier regions and more compact installations requiring less land per unit of electricity produced.
The second study, published in
Joule, extends this analysis to a global scale. Based on satellite images of nearly 69,000 solar installations in 65 countries, the researchers compared the land footprint of rooftop systems and that of large solar power plants, as well as the associated costs.
"This study gives us a comprehensive, and much-needed, analysis of the links between solar energy and land use on a global scale, as well as their techno-economic consequences," specifies Professor Jordaan.
The global analysis shows that rooftop solar installations offer significant potential for land savings. It also reveals that the cost gap between rooftop and ground-mounted systems varies considerably from region to region, making it possible to determine where rooftop installation is most practical. For ground-mounted systems, in many locations, land availability may not always be as significant a constraint as believed.
"Solar projects can have significant local environmental impacts, but our results showed that, in a context of strong solar energy growth, the global land area needed to achieve carbon neutrality is negligible," says Sarah Marie Jordaan. "There are important differences in costs and land availability where targeted and regional policies promote solutions that limit land use, such as solar panels installed on rooftops."
The studies The article "Quantifying land-use metrics for solar photovoltaic projects in the western United States", by Sarah Marie Jordaan et al., was published in
Communications Earth & Environment.
The article "Global land and solar energy relationships for sustainability" was published in
Joule. Both studies were conducted by Professor Jordaan's lab, in collaboration with institutions in North America, Europe, and Asia. This research was supported by the Alfred P. Sloan Foundation and the Natural Sciences and Engineering Research Council (NSERC) of Canada.