The Tenth International Conference on Thermal Energy Storage 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. Bartels GTN Geothermie Neubrandenburg GmbH, Seestrasse 7A, 17033 Neubrandenburg, Germany gtn@gtn-online.de
Geothermal heating plant and lowtemperature network (12 MW, 80 C/45 C) Gas and steam cogeneration plant (77 MW electrical, 90 MW thermal) and high-temperature network (200 MW, 130 C / 60 C) District heat supply by the Neubrandenburg public utilities
heat demand, MWh/h 120 100 80 60 40 20 heat production on maximum load shifting of heat shifting of heat heat production on minimum load surplus heat in summer Jan Feb Jun Jul Aug Dec 0 0:00 4:00 8:00 12:00 16:00 20:00 0:00 Characteristics of the heat demand of Neubrandenburg
Principle of functioning summer charging winter discharging
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 µm 2 2.8 µm 2 Parameters of the geothermal resource
warm well cold well ATES at Neubrandenburg 200 300 400 500 600 700 800 900 10 fibre glass 5 1/2 fibre glass pump 7 liner hanger reducer 10 x 6 5/8 with cone 9 5/8 13 3/4 9 5/8 annulus protective fluid 6 5/8 fibre glass 7 fibre glass Well construction 1000 1100 1200 1300 1285 m 7 liner hanger Hettangian 4 1/2 screen Upper Postera gravel pack 1270 m 7 liner 1400
summer high temperature network low temperature network cold well warm well Functionchart of the aquifer heat store
winter high temperature network low temperature network cold well warm well Functionchart of the aquifer heat store
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 Discharged heat 12,000 MWh/year 8,800 MWh/year Operational parameters of the aquifer heat store (acc. to design)
3,000 heat, MWh/month 2,000 1,000 heat from boiler plant heat from cogeneration plant heat store 0 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Coverage of the heat demand in the course of the year
50% 49.7% heat from cogeneration plant heat from boiler plant Percentage demand coverage by the individual heat producers (without the store)
3% 48% 49% heat store heat from cogeneration plant heat from boiler plant Percentage demand coverage by the individual heat producers (acc. to design)
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 20: Start-up of the first regular heat discharging process November 20: Start-up of the first heat discharging process
90 First period 80 temperature [ C] 70 60 50 40 30 D 04 J F M A M J J A S O N D J 06 F 06 M 06 Temperatures in the first regular year of charging
heating capacity out of the aquifer (+), into the aquifer (-) [MW) 4 3 2 1 0-1 -2-3 -4-5 First period D 04 J F M A M J J A S O N D J 06 F 06 M 06 Heating capacity in the first regular year of charging
0 heat from and into the aquifer [MWh] -2000-4000 -6000-8000 -10000-12000 -14000-16000 charging 14.225 MWh discharging 6.430 MWh A M J J A S O N D J 06 F 06 M 06 Store behaviour in the first regular cycle of operation (cumulative)
heating capacity [kw] 7.000 6.000 5.000 4.000 3.000 2.000 charging heat store direct heating excess heat from cogeneration plant total network heat demand 1.000 0 12:00 16:00 20:00 00:00 04:00 08:00 12:00 Excess heat and its use on. and 06.11.20
temperature [ C] 100 95 90 85 80 75 70 65 60 55 50 45 40 cooling down network heating up store 12:00 16:00 20:00 00:00 04:00 08:00 12:00 T feeding flow T return flow T injection T production District heating network and charged heat temperatures on. and 06.11.20
heating capacity [kw] 7.000 6.000 5.000 4.000 3.000 2.000 conventional afterheating discharging heat store total network heat demand 1.000 0 12:00 16:00 20:00 00:00 04:00 08:00 12:00 Heat demand coverage on 23. and 24.01.2006
temperature [ C] 90 85 80 75 70 65 60 55 heating up network cooling down store T feeding flow T flow - store T return flow T production T injection 50 45 40 12:00 16:00 20:00 00:00 04:00 08:00 12:00 District heating network and discharged heat temperatures on 23. and 24.01.2006
0,4% 44% 56% heat store heat from cogeneration plant heat from boiler plant 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.