Novel machine learning framework estimates the increase in worldwide rooftop surface area, helping town and infrastructure planners realise the climate potential of residential and commercial properties.
According to researchers at the International Institute for Applied Systems Analysis [IIASA], as of 2019 the world’s buildings were using around 18% of all electricity generated and producing some 21% of all greenhouse gas emissions. These percentages are set to grow as the global population increases, however there is also enormous potential for structures to become net contributors to our supply of clean energy and sustainable resources.
Rooftops, for example, can be used to install solar panels, water capturing systems, carbon capture and storage, including green walls. By understanding the overall capacity, urban planners and policymakers will be far better placed to create frameworks, regulations and blueprints to turn towns and cities into places where people live and work, but also actively produce low carbon electricity or supply water into the local network.
IIASA’s new machine learning framework looks to facilitate this through the use of big data for around 700million building footprints, global land cover, road and population information. Published in the journal Scientific Data, rooftop area growth between 2020 and 2050 has been estimated based on five different future scenarios. This includes 3.5million small areas.
At the turn of this decade, global rooftops accounted for 0.25million square kilometres with total human-made built-up surface area amounting to 1.46million square kilometres. Asia made up the highest proportion of this, at 0.12million square kilometres, followed by Europe (0.047million), North America (0.039million), and the Africa (0.02million). By the halfway point of this century, 2050, this area is expected to increase to between 0.3 and 0.38million square kilometres, or 20-52% compared with 2020 figures. Africa will see the highest growth, with almost double the rooftop surface area.
‘The implications of this research for policy and the public are significant. Our dataset can aid in more realistic planning of decentralized solar energy systems, thereby promoting sustainable energy solutions. Estimating the potential of rooftop solar technology in achieving climate policies, especially in emerging economies, can help these policies be more effective and affordable, in line with the Sustainable Development Goals for clean energy, sustainable cities, climate action, and life on land,’ said lead author Siddharth Joshi, a research scholar in the Integrated Assessment and Climate Change Research Group of the IIASA Energy, Climate, and Environment Program.
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Image: IIASA