Solar-Energy Surface Potential 2005
The central work step for the assessment of the Berlin building stock involved the comparison of the typology of the twenty urban-space types with varying solar urban potential, with the section types of the land-use maps of the Berlin City and Environment Information System (ISU). The goal was to check the specific delimitation criteria of the urban-space types for commonality with the the ISU section types. These criteria include:
- Building age
- Building use
- Shape, orientation and design of roofs and façades
- Value in terms of architectural culture (protection of historical monuments), and
- Urban density.
With the aid of high-resolution and geo-referenced aerial photography, an urban-space type was assigned to the ISU section type for every built-up area. For this purpose, the twenty nationally-defined urban-space types were reduced to the seventeen types relevant for Berlin. The result was the creation of an urban-space type/ section type assignment table, which however, in many cases required the multiple assignment of a section type to the appropriate urban-space type (cf. Table 2).
The characteristics significant for the determination of solar-power-surface potential, particularly the available roof and façade surfaces, could in most cases be adequately ascertained from aerial photography. This was also the method used for the specific determination of urban-space types for which there was multiple assignment to ISU section types, according to the Table.
The list of the seventeen urban-space types of building stock relevant for Berlin has been supplemented by four additional categories for planned construction projects (Urban-Space Types 18 -21). However, the areas delimited accordingly on the map should only be seen as indications, since the respective projects were at different stages of planning, and their further development was not foreseeable. Generally, the advantage of projects is their possibility of tying strategies for the use of solar or other regenerative energies into the planning process at an early stage, which may greatly increase their possibilities of realization.
In order to take the district-heating-supplied areas in Berlin into account, the Map 08.01 Building Heating Supply Areas was consulted. The purpose was to include an additional criterion particularly for the conclusive evaluation of Berlin’s overall potential contribution in solar-thermal energy and photovoltaics, respectively, to the future energy supply of the city. If a construction area is already provided with district heating, this approach will permit summertime heating and cooling requirements to be met by this system. In these cases, roof and façade areas suitable for the active solar technology should be considered primarily as potential solar-power sources.