TWO-YEAR EXPERIENCE IN THE OPERATION OF AN AQUIFER THERMAL ENERGY STORE BASED ON SURPLUS HEAT ARISING FROM A GAS AND STEAM COGENERATION PLANT

AT NEUBRANDENBURG / NE GERMANY

F. Kabus, G. Möllmann, F. Hoffmann and J. BartelsGTN Geothermie Neubrandenburg GmbH, Seestrasse 7A,

17033 Neubrandenburg, Germanygtn@gtn-online.de

The Tenth International Conference on Thermal Energy Storage

Geothermal heating plant and low-temperaturenetwork(12 MW, 80°C/45°C)

Gas and steamcogeneration plant (77 MW electrical, 90 MW thermal) and high-temperaturenetwork (200 MW, 130°C / 60°C)

ATES at Neubrandenburg

District heat supply by the Neubrandenburg public utilities

0

20

40

60

80

100

120

0:00 4:00 8:00 12:00 16:00 20:00 0:00

heat

dem

and,

MW

h/h

JanFebJunJulAugDec

surplus heat in summer

shifting of heat

ATES at Neubrandenburg

Characteristics of the heat demand of Neubrandenburg

heat production on maximum load

heat production on minimum load

shifting of heat

Principle of functioning

ATES at Neubrandenburg

summercharging

winterdischarging

• Geological formation Upper Postera sandstone

• Depth 1,228 m – 1,268 m

• Reservoirtemperature 55 °C

• Mineralisation 135 g/l

• Porosity 26.6 %

• Permeability 0.94 µm2 – 2.8 µm2

ATES at Neubrandenburg

Parameters of the geothermal resource

Well construction

ATES at Neubrandenburg

200

300

400

500

600

700

800

900

1000

1200

1300

1100

1400

13 3/4“

5 1/2“ fibre glasspump

9 5/8“

1285 m

4 1/2“ screen

gravel pack

10“ fibre glass

6 5/8“ fibre glass

annulusprotective fluid

Hettangian

Upper Postera

1270 m

7“ fibre glass

7“ liner hanger

warm well cold well

7“ liner hanger

7“ liner

reducer 10” x 6 5/8”with cone 9 5/8”

cold well warm well

high temperature network

low temperature network

cold well warm well

high temperature network

low temperature network

summer

Functionchart of the aquifer heat store

ATES at Neubrandenburg

cold well warm well

high temperature network

low temperature network

winter

cold well warm well

high temperature network

low temperature network

Functionchart of the aquifer heat store

ATES at Neubrandenburg

• Number of wells 2

• Internal distance 1,300 m

• Production and injection flow rate 100 m³/h

• Injection temperature 80 °C

• Discharging temperature (5th year) 78 °C – 72 °C

• Charged heat 12,000 MWh/year

• Discharged heat 8,800 MWh/year

ATES at Neubrandenburg

Operational parameters of the aquifer heat store (acc. to design)

ATES at Neubrandenburg

0

1,000

2,000

3,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

heat

, MW

h/m

onth

heat from boiler plant

heat from cogeneration plant

heat store

Coverage of the heat demand in the course of the year

49.7%

50%

heat from cogeneration plant

heat from boiler plant

Percentage demand coverage by the individual heat producers(without the store)

ATES at Neubrandenburg

49%

3%

48%

heat store

heat from cogeneration plant

heat from boiler plant

Percentage demand coverage by the individual heat producers(acc. to design)

ATES at Neubrandenburg

ATES at Neubrandenburg

“Cold” well head

ATES at Neubrandenburg

Heat exchanger between district heat supply network and intermediate loop

ATES at Neubrandenburg

March 2004:

Start-up of the first heat charging process (Probebetrieb)

December 2004:

Start-up of the first heat discharging process (Probebetrieb)

March 2005:

Start-up of the first regular heat discharging process

November 2005:

Start-up of the first heat discharging process

Temperatures in the first regular year of charging

ATES at Neubrandenburg

30

40

50

60

70

80

90

D04

J05

F05

M05

A05

M05

J05

J05

A05

S05

O05

N05

D05

J06

F06

M06

tem

pera

ture

[°C

]

First period

Heating capacity in the first regular year of charging

ATES at Neubrandenburg

-5

-4

-3

-2

-1

0

1

2

3

4

D04

J05

F05

M05

A05

M05

J05

J05

A05

S05

O05

N05

D05

J06

F06

M06

heat

ing

capa

city

out

of t

he a

quife

r (+)

, in

to th

e aq

uife

r (-)

[MW

)

First period

Store behaviour in the first regular cycle of operation (cumulative)

ATES at Neubrandenburg

-16000

-14000

-12000

-10000

-8000

-6000

-4000

-2000

0

A 05 M 05 J 05 J 05 A 05 S 05 O 05 N 05 D 05 J 06 F 06 M 06

heat

from

and

into

the

aqui

fer [

MW

h]

charging14.225 MWh

discharging6.430 MWh

Excess heat and its use on 05. and 06.11.2005

ATES at Neubrandenburg

0

1.000

2.000

3.000

4.000

5.000

6.000

7.000

12:00 16:00 20:00 00:00 04:00 08:00 12:00

heat

ing

capa

city

[kW

]

charging heat store

direct heating

excess heat fromcogeneration planttotal network heatdemand

District heating network and charged heat temperatureson 05. and 06.11.2005

ATES at Neubrandenburg

404550556065707580859095

100

12:00 16:00 20:00 00:00 04:00 08:00 12:00

tem

pera

ture

[°C

]

T feeding flow

T return flow

T injection

T production

cooling down

network

heating up store

Heat demand coverage on 23. and 24.01.2006

ATES at Neubrandenburg

0

1.000

2.000

3.000

4.000

5.000

6.000

7.000

12:00 16:00 20:00 00:00 04:00 08:00 12:00

heat

ing

capa

city

[kW

]

conventional after-heating

discharging heatstore

total network heatdemand

District heating network and discharged heat temperatureson 23. and 24.01.2006

ATES at Neubrandenburg

40

45

50

55

60

65

70

75

80

85

90

12:00 16:00 20:00 00:00 04:00 08:00 12:00

tem

pera

ture

[°C

]

T feeding flow

T flow - store

T return flow

T production

T injection

heating up network

cooling down store

56%

0,4%

44%

heat store

heat from cogeneration plant

heat from boiler plant

ATES at Neubrandenburg

Percentage demand coverage by the individual heat producers(first period)

This work was financially supported by the Federal Ministry of Economics and Technology of Germany, project no. 0329838B. The authors gratefully acknowledge this support.

ATES at Neubrandenburg