EK-CER researcher involved in preparing the Budapest Solar Map


Tamás Soha, a member of the Energy Strategy and Environmental Effects Research Group of the Environmental Physics Laboratory at the ELKH Centre for Energy Research (EK-CER) has participated as a leading geospatial developer in the creation of the Budapest Solar Map, the Hungarian capital's official solar energy power spatial database. The online application, which has recently been made available free of charge, offers Budapest residents as well as businesses information on the extent to which the roofs of their own properties are suitable for the installation of solar panels, providing them with significant assistance when planning solar developments.

As part of the Budapest Climate Strategy the Hungarian capital has undertaken to reduce its emissions by 40 percent by 2030. Nothing indicates the urgency of this task better than the fact that 25 percent of Hungary's electricity consumption is concentrated in Budapest, which accounts for only 0.5 percent of the country's territory. This consumption is typically accounted for by the burning of fossil fuels. One element of Budapest's comprehensive plan is the decarbonization of the city's electricity production. To this end, it intends to use various incentives to promote the realization of 1,500 megawatts (MW) of installed photovoltaic capacity.

One important stage in this energy transition is the creation of the Budapest Solar Map, Hungary's first large-scale solar power map. With this step Budapest has joined other European cities (such as Vienna, Amsterdam, Helsinki and Berlin) that use an interactive solar map to help residents and businesses plan solar developments.

The compilation of the spatial database of the Budapest Solar Map began in 2021. This was followed by several months of data preparation and, in parallel, the development of a method optimized for local conditions and the possibilities of the project. Among the many components of the database, two notable features are a map layer containing the site plans of the 344,000 buildings of the capital and a digital surface model that enables the most important investigations and covers the entire city. The digital surface model utilizes an active remote sensing method: a point cloud with a 20-centimeter horizontal resolution and an even more precise vertical resolution, produced with the help of LiDAR technology. This surface model has served as the basis for creating raster layers that demonstrate the exposure and tilt angle of the roof surfaces of the buildings. It also provides year-round irradiance modeling with hourly resolution and examines the impact of shade.


The free, easy-to-use web application shows the insolation for each building so that the owners or managers of the properties can determine to what extent the roof of the given building is suitable for installing solar panels. Using the built-in address search engine, clicking on the desired building will display useful information in a pop-up window: the layout of the roof, the size of the parts most suitable for placing solar panels, the total output of the solar panels that can be installed, and the estimated annual electricity production. By evaluating and summarizing the data, the experts determined that the technical photovoltaic power available on the roofs of the capital's buildings is a total of 5,000 MW.

The Budapest Solar Map was designed to be suitable for the integration of other map layers in order to pave the way for other projects in the city. Soha said the information stored in the spatial database provides research opportunities that fit into the Energy Strategy and Environmental Impacts Research Group's investigations into building energy and electricity networks. The evaluation of the data that can be extracted from the database is currently ongoing, and will result in complex analyses, aggregations, geostatistics and other reports that will help the work of the specialists. Additional plans include the spatial extension of the applied model to other Hungarian settlements.