Shallow Geothermal Energy in Germany

Transcription

1 Shallow Geothermal Energy in Germany market situation, best practise, future potential, trends Dipl.-Geol. Rüdiger Grimm

2 Company o o o o o o consulting for shallow geothermal energy since 2007 (1,200 projects) design of borehole Heat Exchanger (BHE) fields simulation of underground conditions geothermal testing: o o Thermal Response Test Temperature-Log site management and inspection monitoring of completed sites o

3 The Market in Germany

4 Anteile Luft & Erde

5 Size of heat pumps

6 Comparing Bundesländer

7 Staufen, II Kongres PORT PC - Warszawa

8 The official version

9 Planning the BHE-design Basement for successful projects

10 Starting with 5 key-points 1. Geothermal applications always involve higher investment. 2. We recompensate the cost by having lower operational costs in the following years. 3. Amortization time is the main deciding factor for or against geothermal usage. 4. The key to high efficiency in operation is planning by experienced professionals. 5. To determine the geothermal conditions, we have to estimate/evaluate the parameters or realize test work.

11 Project Phases (7 Steps) 1. Determining Energy Requirements 2. Underground Assessment 3. Evaluating the Feasibility 4. Planning the Site 6. Installation 5. Carrying out Sample Tests 7. Monitoring

12 VDI 4640, Blatt 2, Tabelle 2 Untergrund spez. Entzugsleistung für 1800 h für 2400 h Allgemeine Richtwerte: Schlechter Untergrund (l <1,5 W/m/K) 25W/m 20 W/m Normales Festgestein und wassergesättigtes Sediment (l =1,5-3,0 W/m/K) 65 W/m 50 W/m 50 W/m cannot be found here! Festgestein mit l > 3,0 W/m/K 84 W/m 70 W/m Einzelne Gesteine: Kies, Sand trocken <25 W/m <20 W/m Kies, Sand wasserführend W/m W/m Ton, Lehm feucht W/m W/m Kalkstein (massiv) W/m W/m Sandstein W/m W/m Saure Magmatite (z.b. Granit) W/m W/m Basische Magmatite (z.b. Basalt) W/m W/m Gneis W/m W/m Starker Grundwasserfluss in Sand/Kies für Einzelanlagen W/m

13 Myth: 50 W/m This standard value comes from VDI 4640 and is mistakenly used internationally W/m is a unit of geothermal power Relevant for design is the unit kwh/yr 10 kw x h/yr is not equal to 10 kw x h/yr W/m is only a preliminary unit for a single house Relevant for a standard building Energy demand varies throughout the year even if the power remains the same The rocks have (very) different physical properties Thermal Conductivity (Factor of up to 4) and prevalence of ground water (Factor of up 6)

14 Maps of geothermal potential Quellen: SMUL

15 Multi layer systems

16 Thermo-hydrodynamic Simulation

17 Multifamiliar Houses Freiberg Typical example for renovation

18 MFH Talstraße 5, 7 & 9 in Freiberg 885 m² living space 12 flats 40 residents 90 kwh/m²*a projected heat demand Building Costs: 1.36 M. Cost/m 2 : 7.10 /m² Heating cost/m 2 : /m² 6 boreholes m separate buffer storage 18

19 Age of residencial buildings 30 million old buildings 1 millions of them with energetical restoration 46% older than 35 years

20 Initial Situation Architect's estimation 3 x 25 kw = 75 kw = 50 W/m x 1,500 m = 15 x 100 m 89, % Safety Factor = 98,000 7,2% of total cost Heat calculation by engineer 48 kw without hot water 39 Persons x 0,3 kw = 12 kw Total heat demand: kwh/yr heating kwh/yr hot water

21 Geothermal Pre-Design Preliminary geothermal energy study Gneiss Thermal Conductivity: 2,9 W/m,K Range of EED database: 1,9 4,0 W/m,K Underground temperature: Freiberg (EED database): 7,7 C Result of EED analysis: 6 x 140 m = 840 m Cost estimation: 55,000 Recommendation for pilot BHE for test work Further EED calculations based on test results Cost Outline

22 Temperatur [ C] Volumenstrom [l/min] Thermal Response Test (TRT) Pilot drilling and BHE installation Depth of the borehole same size as future hole BHE location is important as it will be integrated into the future field Thermal Response Test gives important design-parameters: Thermal Conductivity Borehole resistance Underground temperature 72 hour test period Vorlauftemperatur Rücklauftemperatur Lufttemperatur Volumenstrom II Kongres PORT PC - Warszawa Zeit [h]

23 Temperatur [ C] Volumenstrom [l/min] Data and Results Vorlauftemperatur Rücklauftemperatur Außentemperatur Volumenstrom Zeit [h] Ergebnisse des Thermal Response Tests mittlere ungestörte Untergrundtemperatur T mittel 10,74 C gruond surface temperature T ground 9,69 C effektive Wärmeleitfähigkeit λ* 3,43 W/m,K thermischer Bohrlochwiderstand R b 0,085 K/W/m Sondenlänge (berechnet aus TRT) l TRT 120 m

24 Detailed Plan Reduction of total drilling 6 x 107 m = 640 m Comparing: m (Architect) 840 m (Pre-design) Optimization of field Considering hydraulic conditions Cost estimation: II Kongres PORT PC - Warszawa

25 COP / SPF

26 Public Display

27 Berufskolleg Mitte Duisburg largest project of shallow geothermal use in Germany

28 The building

29 Object data 2,600 students daily 55,900 m² User: Municipality of Duisburg PPP for 25 years (heating, cooling, domestic hot water, electricity ) operated by GOLDBECK PPP GmbH DGNB-certified (German standard for green buildings ) Investment: 73.8 Mill. 180 BHE (110 to 130 mts each) 21,600 mts 1.9 MW heating & 1.0 MW cooling

30 Top 10 Germany (2011)

31 Involved partners Costumer Planner Driller Heat pump

32 Grundlast [MWh] Grundlast [MWh] BHE-design (detail 1: temperatures) JAN FEB MÄR APR MAI JUN JUL AUG SEP OKT NOV DEZ JAN gfedcb gfedcb gfedcb gfedcb gfedcb WW Grundlast Heizen Grundlast Kühlen Grundlast gesamt Grundlast Erdseite JAN FEB MÄR APR MAI JUN JUL AUG SEP OKT NOV DEZ JAN gfedc gfedcb gfedcb gfedcb gfedcb WW Grundlast Heizen Grundlast Kühlen Grundlast gesamt Grundlast Erdseite standard load specific load gfedcb gfedcb gfedcb gfedcb Min. bei Spitzenlast Max. bei Spitzenlast Min. bei Grundlast Max. bei Grundlast Jahr

33 BHE-design (detail 2: deviation)

34 BHE-design (detail 3 model) FEFLOW boundary conditions licensing requirement coordination with geolocal survay influence to the neighborhood old mining temperature field groundwater dynamics in the upper aquifer

35 BHE-design (detail 4 configuration) 180 BHE under the building 15 subfields 12 BHE each Depth from 110 mts to 130 mts within one subfield similar connection legth (pressure loss per subfield: 6 mts) one central manifold

36 Drilling

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38 Heatpump concept KWT Kälte- Wärmetechnik AG

39 KWT Kälte- Wärmetechnik AG Heating HP1 heat power [0/38 C]: 529 kw input power: 125 kw COP: 4,2 HP2 HP3 heat power [0/38 C]: 529 kw input power: 125 kw COP: 4,2 heat power [0/38 C]: 529 kw input power: 125 kw COP: 4,2 HP4 heat power [13/60 C]: 311 kw input power: 226 kw COP: 3,6

40 KWT Kälte- Wärmetechnik AG Passive cooling HP1 HP2 HP3 HP4

41 KWT Kälte- Wärmetechnik AG Active cooling HP1 cooling power [13/32 C]: 776 kw input power: 109 kw COP: 7,1 HP2 HP3 HP4 cooling power [13/32 C]: 262 kw input power: 44 kw COP: 5,9

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44 Monitoring

45 Conclusions 1. Each large geothermal-based building is a unique case. 2. It requires interdisciplinary cooperation and continuous variations of the modelling parameters (building AND underground). 3. In the first years of operation, geothermal systems can almost be optimized and the system efficiency can be increased. 4. The implementation of a monitoring system is a basic requirement for this. 5. Probably there is a size limit for shallow geothermal applications (due to hydraulic borders and their economic consequences in the operating costs).

46 Special solutions Some examples

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48 Projektübersicht 7 manifolds radial drilling 5,000 drilling meters special probes: coaxial 48

49 Kornhaus Freiberg General: historic public building (library) in the old town centre of Freiberg bivalent system: gas and geothermal 2 HP (45 kw each) Drilling/Hydraulic: 205 m Pilot-BHE for TRT (= deepest BHE in Saxony) Single-U-Probe 40 x 3,7 mm Turbocollector MUOVITECH 2014: 9 BHE á 205 m

50 Situation in Germany 2013 With yearly 20,000 new built units Germany is the main market for shallow geothermal use in Europe. But the numbers are slowly decreasing (legal aspects, energy prize). There are strong regional differences between the States based on the federal system and the interpretation of the Water- and Mining-Law. Those differences are caused on Public presence of some bad practise examples geological conditions of the underground conflicts with groundwater uses We can observe a wide discussion about legal aspects, certification, drilling quality, innovative materials, site-controlling, risc ensurance.

51 Situation in Germany 2013 The system-efficency and successfull planning is not in the main focus. For the design of BHE the underground parameters has an important role because of the investment costs. There is a wide range of planning-tools (maps, TRT, T-Log, modelling software). The required additional costs ensure accuracy and optimal costs relation between investment and efficiency. Field Tests are state-of-the-art. Besides the conventional results (Thermal Conductivity, Temperature), we can obtain additional information. Main future fields will be the restoration of residence buildings and commercial uses of heating & cooling.

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