Solar cadastre NRW: Potential data Roof surface solar thermal

The NRW solar cadastre was developed on the basis of nationally available high-resolution laser scanning data (data source: Country NRW). Every year, a part of NRWs is reflyed, usually on a 5-year cycle. From the laser scan data, a comprehensive digital surface model (DOM) was created in a resolution of 0.5 meters by 0.5 meters for roof area analysis. The dataset contains the year of flight for each roof area. For the potential analysis of the roof surfaces, all roof areas in North Rhine-Westphalia could be determined by interlinking these data with a map of all building outlines. In turn, the roof surfaces were disassembled into homogeneous sub-areas, each of which has a uniform inclination and orientation and can therefore be proved equally for solar modules. Due to the high resolution of the digital surface model and the dismantling into homogeneous sub-areas, small-scale roof elements such as chimneys, dormitories, woods and other interrupting structures could be identified. Using radiation data from the German Weather Service, the solar radiation as well as its percentage shading was calculated for the whole of NRW – taking into account the daily and seasonal changes in radiation. Shading can be caused by trees, adjoining buildings, roof structures or terrain elevations. Severely shaded areas as well as too small areas were taken out of the further calculation as unsuitable. Subsequently, a variety of parameters could be calculated for each roof area that can be documented with modules, such as the usable module area, the installable power and the potential heat yield. Structural factors such as the condition and statics of the roof or building or the properties of the subsoil cannot be recorded on this data basis. For this purpose, a separate professional examination is required in detail. This dataset contains the results of this analysis. The dataset includes the roof areas classified as suitable for solar thermal in North Rhine-Westphalia. The suitability was assessed on the basis of the following criteria: Roof areas suitable for solar thermal use have a radiation energy of 800 kilowatt hours per square meter per year. For the use of thermal systems, a minimum area size of five square metres was used for inclined roofs. Flat roofs shall have at least 12.5 square meters for solar thermal use when changing the modules.