As more and more population from rural areas migrate to cities, city limits expand and more and more houses are built to accommodate the incoming population. As cities expand and house numbers grow, it is generally believed that these rooftops are a means of space wastage.
Urban rooftops are often seen as being wasted space, but they can be used for a number of things. One way to use them is to install solar panels and other forms of renewable energy in order to produce clean electricity and heat. Another option would be to plant vegetation on the rooftop, which could help with cooling and air quality in urban areas. These types of roofs also have many benefits for cities: they increase the amount of green space, reduce storm water runoff into sewers, lower temperatures by reducing heat absorption from buildings during hot weather periods, and reduce pollution by absorbing carbon dioxide from the atmosphere. They’re also economical because they don’t require additional land or fresh water resources such as agriculture or irrigation systems like ground-based vegetation.
However, a new way of fighting climate change is presented in the form of sustainable rooftops emerge and cities around the world have already started adopting this method to battle climate change slowly. With more and more households adopting sustainable rooftops, it is believed that cities can use the data from these rooftops to build a roadmap for reducing the carbon footprint of cities but while studies have been done to gauge their potential, few track the actual performance of cities.
Researchers in Singapore have developed an automated tool that uses satellite images to track how rooftops around the world adopt solar panels and/or vegetation. Known as Roofpedia, it uses a fully convolutional neural network (deep learning) which allows researchers and policymakers to study how cities worldwide are greening their rooftops and using them for photovoltaic installations. Their research was published in the international journal Landscape and Urban Planning.
With Roofpedia, the researchers created an open roof registry with data from 1 million rooftops across 17 morphologically and geographically cities, spanning Europe, North America, Australia, and Asia. These cities are: Berlin, Copenhagen, Las Vegas, Los Angeles, Luxembourg City, Melbourne, New York, Paris, Phoenix, Portland, San Diego, San Francisco, San Jose, Seattle, Singapore, Vancouver, and Zurich.
Based on the Roofpedia Index, Singapore is ranked third out of the 17 cities, with a score of 75, for rooftop solar adoption, trailing behind Las Vegas (score of 86) and Zurich (score of 81). The scores in the Index are normalised, and while Singapore scored highly on total area coverage, it is behind some other cities for having relatively fewer buildings equipped with solar panels.