SOLARGE

Wohnungsgenossenschaft "Karl-Marx" e. G.

Potsdam, Germany

Multi-family house | 200 sqm installation

 


Project summary · Technical description · Financing · Development · Downloads

Project Summary

Description

The presented residential building is a multi-storey-building of 11 floors, built in the typical tower block style of the 70‘s. In 2000 a comprehensive reconstruction was done including energy related measures like insulation of facade, basement ceilings and lobby as well as a windows modernisation. Furthermore the hole heating and hot water station was renewed. Today heat supply is effected by district heat from a combined heat and power generation and by the 222 sqm (gross area) large solar thermal plant for a certain share of the hot water demand.



 


Building

Type of building

Multi family house

Number of dwellings, floors

258 dwellings
11 floors

Year of construction

1974

Total effective area (heated)

15,522 m2

Hot tap water consumption (measured/estimated)

4,900 m3/a (measured)

Whole energy consumption for heating purpose after CSTS implementation

1,492,000 kWh/a


System engineering

Year of construction of CSTS

2000

Type of collectors

Flat plate collectors

Thermal power

not available

Aperture area of collectors*)

not available 

Buffer storage

9.75 m3

Hot tap water storage

2.25 m3

Total capacity of boilers with energy source

995 kW,
District heating

Type of hot tap water heating

Centralised

Type of heating system

Centralised


Costs

Total cost solar system

200,000 Euro

Cost of the CSTS/gross area of collectors

900 Euro/m2

Subsidies

./. %


Output

Output of solar heat**)

66,202 kWh/a

Reduction of final energy***)

88,270 kWh/a

CO2-emissions avoided

not available

Solar performance guarantee

No


*) Aperture area = light transmitting area of the front glass
**) measured, between storage and piping to taps (solar system output)
***) related to the measured output mentioned before

 

 


Mr. Bergemann, WG “Karl-Marx“ Potsdam e. G.:

Within the scope of the refurbishment of the building a complete modernisation of the heating system including central hot water generation was necessary. For that reason among others the possibilities of an integration of solar energy were analysed. Although hot water generation by a solar thermal system seemed to be a favourable option the implementation was a great task for the involved planners and manufacturers as well as for us as the building owner. It has to be pointed out that by time of the planning in 1998 large solar thermal systems for residential buildings were just rare realized so that there was just little experience background for the project.
From the point of view today we can draw a positive balance: The results regarding technical and economic performance meet all the foreseen levels.

 

 


Owner

Owner
Wohnungsgenossenschaft “Karl Marx“ Potsdam e.G.
Mr. Klaus Bergemann
Jagdhausstraße 27
D-14480 Potsdam, Germany
Phone: +49 331 6458-235
bergemann(at)wgkarlmarx.de
www.wgkarlmarx.de


Operator

see Owner

Top of page Project summary · Technical description · Financing · Development · Downloads

Technical description

 


Description of the CSTS

Year of construction of CSTS

2000

Thermal power

not available 

Gross area of collectors

222 m2

Aperture area of collectors

not available 

Type of collectors

Flat plate collector

Type of assembly

On flat roof

Orientation of collectors

South-West (+34°)

Inclination angle to horizon

45°

Freezing protection

Glycol

Overheating protection

not available

Operation mode

Low flow

Use of CSTS for

Hot tap water heating

Buffer storage

9.75 m3

Hot tap water storage

2.25 m3

Control of backup-system/CSTS

Separated control


Hot tap water system

Type of hot water heating

Centralised

Recirculation system

Yes

For decentralised systems:
The installation on the consumer site

./.

Size of storage for hot tap water

2.25 m3

Specification (if necessary)

./.


Space heating system

Type of heating system

Centralised

Number of boilers

1

Total capacity (power output) of boilers

995 kW

Capacity of each boiler (year of construction)

./.

Energy source

District heating
(from CHP)

Type of boiler system

./.


Type of operation

Operator of the CSTS system

Self-operation

CSTS monitoring

Yes (Output of solar heat, hot water consumption; regular meter reading by instructed caretaker, evaluation and reporting by own personal (building service engineer))

Data accessible via internet

No

Scientific monitoring & follow up

No

Maintenance contract

Yes (once a year)

Visualisation of the solar heat output

Yes, display in the lobby


Yield of CSTS plant

Output of solar heat

66,202 kWh/a

Origin of data

Measured

Measuring point

Between storage and piping to taps

Reduction of final energy

88,270 kWh/a

Origin of data

Measured

Solar performance guarantee

No


Heat consumption

Whole energy consumption for heating purposes after CSTS implementation

1,492,000 kWh/a

Origin of data

Measured

Energy used for heating of

Hot tap water heating, Space heating

Whole energy consumption for heating purposes before CSTS implementation

not available

Total tap water consumption

not available

Hot tap water consumption

4,900 m3/a

Hot tap water temperature

55 °C

Cold water temperature

10 °C

 

 


Summary

The solar thermal system consists of a 222 sqm collector field connected with a separated control unit and storages. The solar thermal energy is only used for hot water generation.


 


Planner

 


Installer



Producer

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Financing and investment

Introduction

The purchase of the system has been financed by soft loans and a 15% self financing. The total costs of all implemented modernisation measures (including CSTS) will be shared by the tenants within the legal ranges.


 


Financing of the CSTS

Form of financing

Purchase

Distribution in percentage

85 %


Costs of solar materials

Total cost of solar system

200,000 Euro


Detailed costs for

Collectors

not available

Elevation/mounting structure

not available

Storage, heat exchanger

not available

Back-up heater

not available

Control

not available

Installation

not available

Planning/Engineering

not available

Other

not available


Operation costs of heating system

Power cost for pumping

not available

Maintenance cost

not available

Monitoring cost

not available

Other operation cost

not available

Total operation cost

not available

or: Increase of the operation cost after CSTS implementation

not available

 

 

Special note for subsidy systems in the partner country

52% from soft loans of investment bank Brandenburg (ILB); 33% from soft loan of Reconstruction Loan Cooperation (Kreditanstalt für Wiederaufbau – KfW)
Name of program for soft loans:
- ILB: modernisation in existing stock
- KfW: program refurbishment of multi-storey buildings
(both closed)

 

 


Addresses

InvestitionsBank des Landes Brandenburg
Steinstraße 104–106
D-14480 Potsdam
Phone: +49 33 1660-0
Fax: +49 33 1660-1234
postbox(at)ilb.de
www.ilb.de

Federal Office of Economics
and Export Control (BAFA)
Frankfurter Straße 29–35
65760 Eschborn, Germany
Phone: +49 6196 908-0
Fax: +49 6196 908-800
www.bafa.de

KfW – Kreditanstalt für Wiederaufbau
Palmengartenstrasse 5–9
60325 Frankfurt am Main
Tel: +49 69 7431-0
Fax: +49 69 7431-2888
info(at)kfw.de

 

Top of page Project summary · Technical description · Financing · Development · Downloads

Development & experiences

Summary of experiences / Notices to the project performance

The experiences with the presented project underline that solar thermal systems are suitable for an implementation in large residential buildings. It was shown that technical and economical target values can be reached. As key factor for the implementation a good knowledge about consumption profile before installation of the CSTS has to be pointed out. A remote monitoring ensures an enduring functionality of the system.

 


Experiences management

Experienced problems or failures?

No (just little)

Found solutions to these problems or failures?

Yes


Financial effects / project performance

Project economically efficient?

No

Fiscal or other financial effects?

No

Effects on rental fees?

No


Experiences technical staff

Experienced problems or failures?

not available

Found solutions to these problems or failures?

not available

 

 


Addresses


 

Top of page Project summary · Technical description · Financing · Development · Downloads

Downloads

SOLARGE_goodpractice_de_karlmarx.pdf

this datasheet in printable PDF-format

2.3 M

WG-Karl-Marx_scheme_large.gif

the hydraulic scheme.

294 K