Solar District Heating with Seasonal Thermal Energy Storage in Germany

(1)

Steinbeis

Research Institute

for Solar and

Sustainable

Thermal

Energy Systems

www.solites.de

Solar District Heating with

Seasonal Thermal Energy Storage

in Germany

(2)

(3)

Steinbeis Research Institute for Solar and Sustainable Thermal Energy Systems www.solites.de

Solar District Heating with Seasonal Thermal Energy Storage

• Introduction

• National research programmes

(4)

Solites - Steinbeis Research Institute for Solar and Sustainable

Thermal Energy Systems

• Concept- and project development of sustainable energy supply systems

(heat, cold and electricity, high reduction of CO

₂

-emissions)

• Comprehensive energy concepts for buildings

(adjustment of architectural concept, thermal insulation, building services and RES)

• Advisor to different ministries and international organisations (IEA/ OECD, EU, GER)

(R&D for large scale solar thermal systems, STES and RES)

• Surveyor for large scale solar thermal systems with STES

• Chairman of the German experts group on seasonal thermal energy Storage

• Member of several international experts groups

(R&D for large scale solar thermal systems, STES and RES)

Member of the Steinbeis Foundation:

• turnover in 2010 over 100 Mio Euro

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Background of scientific R+D

• 1992 – 2003:

Solarthermie-2000

– Part 3

part 3: Central Solar Heating Plants with Seasonal Storage (CSHPSS)

• Development of seasonal storage concepts

• Realisation of eight pilot plants

• 2004 - 2008:

Solarthermie2000plus

one central point: Seasonal Thermal Energy Storage (STES) for:

• solar

• waste heat

• cooling

• combined heating & cooling

• CHP, biomass

• etc.

• Since 2009:

R+D programme for solar thermal systems and storages

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System concept of a central solar heating plant with seasonal storage

Solar collectors

Seasonal

thermal energy storage (STES)

Central heating

plant

District heating

network

Solar

_network

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CSHPSS in Hamburg, 1996

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Solar fractions of solar thermal systems

He

at

amo

un

t

Solar irradiation

Total heat

demand

Central Solar Heating Plant with

Seasonal Storage

Domestic hot water system (100 % solar in summer)

Combisystem (hot water and space heating)

Jan

Feb

Mar

Apr

May

June July

Aug

Sep

Oct

Nov Dec

7 – 10 %

Solar fraction:

15 – 20 %

~ 50 %

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Seasonal Thermal Energy Storage (STES) – Concepts

Pit thermal energy storage (PTES)

(60 to 80 kWh/m³)

Borehole thermal energy storage (BTES)

Aquifer thermal energy storage (ATES)

(30 to 40 kWh/m³)

Tank thermal energy storage (TTES)

(60 to 80 kWh/m³)

(15 to 30 kWh/m³)

Pit thermal energy storage (PTES)

(60 to 80 kWh/m³)

Borehole thermal energy storage (BTES)

Aquifer thermal energy storage (ATES)

(30 to 40 kWh/m³)

Tank thermal energy storage (TTES)

(60 to 80 kWh/m³)

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Hamburg (1996)

3.000 m² FPC

4.500 m³

Tank

Friedrichshafen

(1996)

4.050 m² FPC

12.000 m³

Tank

Neckarsulm (1997)

5.300 m² FPC

63.300 m³

BTES

Steinfurt (1998)

510 m² FPC

1.500 m³

Pit

Rostock (2000)

1.000 m² FPC

20.000 m³

ATES

Hannover (2000)

1.350 m² FPC

2.750 m³

Tank

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Chemnitz, 1st CS

(2000)

540 m² VTC

8.000 m³

Pit

Munich (2007)

2.900 m² FPC

5.700 m³

Tank

Eggenstein (2008)

1.600 m² FPC

4.500 m³

Pit

Attenkirchen (2002)

800 m² FPC

500 + 9.350 m³

Tank + BTES

Crailsheim (2008)

5.300 m² FPC

100 m³ + 480 m³

Buffer Tanks

37.500 m³

BTES

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The CSHPSS in Munich: installation of solar collectors, 2007

Start of operation: 2007

24.800 m² heated area (2.300 MWh/a)

2.900 m² solar collectors

5.700 m³ tank

Solar fraction: 47 %*

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Site plan

heat transfer substations

in buildings

buildings without

solar collectors

thermal

energy

storage

solar network

_{local heat distribution network}

central

heating

plant

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The CSHPSS in Crailsheim

service area:

260 apartments, school, gym.

heat demand: 4.100 MWh/year

solar collectors: 7.300 m² (aperture)

buffer storage: 100 + 480 m³ (water tank)

STES:

37.500 m³ (BTES)

el. heat pump: 530 kW

solar fraction:

50 % (design)

solar heat cost: 19 Euro-Cent/kWh

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Solar collector fields in Crailsheim

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Investment cost of seasonal thermal energy storages

0

50

100

150

200

250

300

350

400

450

500

100 1,000

10,000

100,000

In

v

e

s

tm

e

nt

c

os

t p

e

r m

³ wate

r e

qu

iv

a

le

nt

[€

/m

³]

Storage volume in water equivalent [m³]

realised

study

Tanks

Pits

BTES

ATES

Neckarsulm (1. phase) Rottweil Stuttgart Hamburg (HW) Friedrichshafen (HW) Berlin-Biesdorf Potsdam Chemnitz (K/W) Rostock Steinfurt (K/W) Bielefeld Hanover Ilmenau Kettmann-hausen Crailsheim Aquifer Munich Crailsheim Aquifer Eggenstein

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Outlook: R&D-targets for STES

• Materials and wall constructions for combined thermal and pressure stress

(>100 C water / steam)

• Two fields of developments:

• Large scale storages above 1.000 m³

• Buffer storages between 100 und 500 m³.

• Improved reliability of storages

• Multi-functionality (heat sources, long-term / short-term etc.)

• Optimisation on total system level

• Comprehensive design and realisation process

Target 2020: The first technologies of seasonal thermal energy storage

for high solar fractions and excess heat storage

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Contact and Support

Coordinator:

Solites

Steinbeis Research Institute for Solar and Sustainable

Thermal Energy Systems

Dipl.- Ing. Thomas Pauschinger

pauschinger@solites.de

Supported by:

The sole responsibility for the content of this document lies with the authors. It does not necessarily reflect the opinion of the funding authorities. The funding authorities are not responsible for any use that may be made of the information contained therein.