Friedrichstraße 133

Berlin-Mitte, Germany

Multi-family house | 22 sqm installation



The assessment deals with a solar thermal system to be installed on a Wilhelminian style building in the very centre of Berlin. The building has been renovated (roof, heating system) beginning in autumn 2007.
The investor was informed and motivated for solar thermal during the Berlin SOLARGE campaign.
The building is suitable for a solar thermal plant – the collectors may be integrated on the south orientated roof of the side building. Two systems (hot water generation and combined system) have been compared from technical an economical point of view.
The proposed system for hot water generation reaches economical feasibility and is likely to be implemented.



Type of building

Multi-family house

Number of dwellings, floors

20 dwellings + office area

Year of construction


Total effective area (heated)

2,500 m2

Hot tap water consumption

ca. 402 m3/a
(1,100 l/d)

Whole energy consumption for heating purpose (present situation)

not available

Proposed CSTS (main variant)

Type of collectors

Flat plate collectors

Thermal power

14.1 kWtherm.

Aperture area of collectors*)

20.14 m2

Buffer storage

2.0 m3

Hot tap water storage

0.7 m3

Total capacity of boilers

180 kW

Type of hot tap water heating


Type of heating system


Estimated Costs

Total cost solar system

16,000 Euro

Cost of the CSTS/gross area of collectors

730 Euro/m2

Available Subsidies

32 %

Predicted System Output

Output of solar heat

9,440 kWh/a

Reduction of final energy

ca. 13,340 kWh/a
(1,334 m3 gas / a)

CO2-emissions avoided

3 t CO2/a

*) Aperture area = light transmitting area of the front glass


Proposed System Scheme



Friedrich Meiser / Berlin-Kontor

Assessment by

Berliner Energieagentur GmbH



This assessment summary (English)

371 K


Detailed assessment report, 18 pages (German)

429 K