Dresden maps all roofs in the city, to see if they’re suitable for solar

Authorities have published two maps, one of the roofs and the other – of facades so that locals can make the right decision when choosing green energy

Last week, local authorities in Dresden, Germany, unveiled several new digital tools that would greatly help the city’s private residents adopt solar energy. Officials published two interactive maps of the city, one 3D and one flat, to give people an overview of the suitability of their houses for roof or façade photovoltaics.

The maps were developed by the Leibniz Institute for Ecological Spatial Development Dresden using tools for solar potential analysis developed by the Chair of Geoinformatics at the Technical University of Munich. Anyone can use both resources and figure out the best way to integrate green energy into their building profile. With this, the city hopes to boost technology adoption by offering residents clear cost-benefit terms.

Dresden’s solar potential

Based on the maps, city officials have tried to calculate Dresden’s solar potential – the potential maximum energy that the 135,583 buildings can produce. According to analyses, the theoretical output of the city can be around 1,900-gigawatt hours of solar energy, including 400-gigawatt hours coming from facades, per year.

However, that estimate includes protected buildings and areas with a low power output that would be unprofitable to use. A more realistic estimate, with quick and easily accessible roof and façade installations would be able to produce just 500-gigawatt hours per year, relying on largely flat, unlisted roofs.

Compared to Dresden’s overall energy consumption of 2,500 gigawatts per year, this could lead to an easy 20% reduction in consumption, according to the city’s Environmental Mayor Eva Jähnigen.

At the same time, the city also has some potential to expand in façade-mounted installations. The 3D map can give a quick overview of the solar potential on buildings’ sides. Although on average they are less profitable than roofs, because they get less direct sunlight, in some cases they can still be profitable and contribute to decarbonisation and generating more renewable energy.