Mapping of solar potential involves assessing solar irradiation and identifying suitable locations for the installation of solar thermal collectors and photovoltaic systems. For solar thermal, mapping focuses on areas that can be effectively connected to district heating networks — such as rooftops of public buildings or nearby open land suitable for large collector fields. For PV, the analysis concentrates on roof surfaces and other available areas with optimal orientation and minimal shading, supporting electricity production for heat pumps and other auxiliary systems. The estimated potential is based on solar radiation intensity, technical feasibility and the proximity to local heat demand or network infrastructure. Mapping the potential for renewable integration in a district heating system is typically performed by regional agencies, research institutes, or consultants using standardized European methodologies. (see also IEA DHC, Annex TS5 – Methodologies for Renewable Energy Source Potential Assessment, 2023)
The technically feasible potential for solar thermal supported DH networks (open space solar thermal energy) was assessed in RES-AT-2040 based on Geosphere Austria's 100×100 m solar cadastre (GIS data) applying the following methodology:
- Identification of suitable areas (suitable land uses minus protected areas),
- Identification of areas in the vicinity of heating network areas (exclusion of areas outside economically viable distances),
- Evaluation and classification of the remaining suitable areas according to the annual area-related irradiation; Yield calculation per suitable area using regression models for the estimation of solar thermal yields from the local global radiation on the solar collector modules.
According to RES-AT-2040 the majority of the suitable areas identified are sufficient to achieve feasible coverage ratios for heating networks. Thus, using less than 15 % of suitable areas for open space solar thermal plants in municipalities is usually sufficient to cover up to 25 % of the (DH system) heating demand with solar thermal energy.
