Geothermal Energy Storage

Transcription

1 Geothermal Energy Storage SedHeat Workshop, UTAH March Maurice Dusseault University of Waterloo

2 Energy Storage Everyone talks about batteries, but Cost, space, environmental impacts Let s consider the issue of long-term energy storage at a large scale OPTIONS: Pumped hydro very well understood and used Compressed Air Energy Storage in salt caverns (or porous reservoirs) understood, but not used Geothermal heat storage used in shallow geothermal, but not at a significant scale

3 Where Will Energy Come From? Issues: Regularity Energy storage Vibrations Transmission Location Visual impact

4 Where Will Energy Come From? Issues: Regularity, weather Energy storage Panel area needed Transmission Location

5 Pumped Hydro Sir Adam Beck Niagara-on-the-Lake

6 Compressed Air Energy Storage wind power sun power Heat storage grid CA CA turbine m CA storage Salt cavern, saline aquifer CAES Approach

7 Hydro & CAES The conditions in most of Canada are not suitable for these two options Pumped hydro needs a large reservoir, good vertical drop, excess power being generated nearby during low use phases CAES needs salt caverns or a suitable porous reservoir absent over 85% of Canada Geothermal heat storage??

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9 Geothermal System Elements 1 Water lagoon 2 Pump house 3 Heat exchanger 4 Turbine hall 5 Production well 6 Injection well 7 Hot water to district heating 8 Porous sediments 9 Observation well 10 Crystalline bedrock Geothermie_Prinzip.svg: *Geothermie_Prinzip01.jpg: "Siemens Pressebild" From Wikipedia

10 Geothermal North Project Deep geothermal energy extraction from warm dry rock Co-generation: some electricity, some heat Ideal for cold climate communities Holes with new drilling developments Hydraulic fracturing to link wells Environmentally sustainable, resilient, suitable for mining camps and communities Energy for military and sovereignty issues

11 Geothermal Energy in Canada?? Geological Survey of Canada

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13 Naturally Fractured Rocks eb347a30d847.jpg

14 Enhanced Rock Mass Flow Capacity σ hmin

15 Aperture Opening, Shear Dilation

16 Enhanced Conductivity Zone

17 Deep EGS Enhanced Geothermal Systems EGS The Major Issues Cost of deep drilling to access heat because of a low geothermal gradient Fluids from depth cannot be disposed of into rivers or lakes (must be recirculated ) Scaling of pipes in the primary loop must be managed Access to a large enough volume of rock is needed to make it viable Must be at least 20 MW project scale Steady, reliable, no-c, small footprint

18 The EGS Concept From Wikipedia 1 Water lagoon 2 Pump house 3 Heat exchanger 4 Turbine hall 5 Production well 6 Injection well 7 Hot H 2 O to district heating 8 Porous sediments 9 Observation well 10 Crystalline bedrock What V is needed? Geothermie_Prinzip.svg: *Geothermie_Prinzip01.jpg: "Siemens Pressebild"

19 To Implement EGS Has to be deep enough to access elevated temperatures for power + heat In most of Canada, this means depths greater than 4 km Wells must be drilled economically As wide apart as feasible Hydraulically fractured for communication and a binary circulation system used District heating is the major application Minimum MW??

20 Strada Energy Geothermal drilling Claims up to 25 m/hr in granite at 1 km depth Double drill pipe, reverse circulation Espoo geothermal project 7 km deep 40 MW capacity

21 Finland OTA-1 drill site concept 7 km Heat

22 7 km Deep Drilling Rig

23 7 km deep 40 MW granite

24 m Interwell Communication m surface casing cement production casing 3 7 km wellbores overburden rocks hot dry rock reservoir hydraulic fracture stages

25 300 m 300 m 300 m 00) ec.00) JOB TITLE :. (*10^3) Well UDEC (Version Offsets 5.00) UDEC and (Version 5.00) Stresses LEGEND LEGEND 9-Mar :02:53 cycle JOB TITLE 2988:. time = 2.563E-01 sec flow UDEC time (Version = 2.563E ) sec joints with FN or SN = 0.0 boundary plot LEGEND JOB TITLE :. 12-Mar :36:24 cycle JOB TITLE 2988:. time = 2.563E-01 sec flow UDEC time = (Version 2.563E ) sec joints with FN or SN = 0.0 boundary plot LEGEND Simul-frac# (*10^3) Simul-frac# (*10^3) (*10^3) Simul-frac# ) sec.0 s xx =30 MPa 11-Mar :31:04 cycle 2688 time JOB = TITLE 2.305E-01 :. sec flow s yy time =15 = MPa 2.305E-01 sec joints UDEC with FN (Version or SN = ) boundary plot 13-Mar :00:22 cycle 2688 time JOB = TITLE 2.305E-01 :. sec flow time = 2.305E-01 sec joints UDEC with FN (Version or SN = ) boundary plot (*10^3) (*10^3) LEGEND LEGEND c Inc. USA s xx =30 MPa s xx =30 MPa 11-Mar :50:51 cycle 2238 time = 1.919E-01 sec sflow time = 1.919E-01 sec yy =20 MPa joints with FN or SN = 0.0 boundary plot Itasca Consulting Group, Inc. Minneapolis, Minnesota USA Itasca Consulting Group, Inc. Minneapolis, Minnesota USA (*10^2) (*10^2) (*10^2) s yy =30 MPa 12-Mar :33:50 cycle 2238 time = 1.919E-01 sec flow time = 1.919E-01 sec joints with FN or SN = 0.0 boundary plot , Inc. USA Itasca Consulting Group, Inc. Minneapolis, Minnesota USA 300 m Itasca Consulting Group, Inc. Minneapolis, Minnesota USA 300 m (*10^2) (*10^2) (*10^2) m

26 not just power Developing Geothermal Energy mostly district heating. Hydraulically fractured region

27 The Binary EGS Cycle Special low ΔT turbine nger.wordpress.com/tag/e nhanced-geothermalsystems/ Fractured region

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29 Energy Storage & EGS Is it possible to store energy in a geothermal system? The only feasible means seems to be storing energy as heat From where? Here is a concept to be studied Solar energy can be stored as heat And if the time scale is annual, there are definite economic advantages in Canada

30 Parabolic reflector Solar Energy Photovoltaic solar panels are 10-15% efficient (will improve somewhat) Thermal collection can be 70-75% efficient, T > 200 C The problem is: Where do we store the thermal energy? Absorber Tubes Focal point Parabolic reflectors

31 Operate EGS in Reverse! From Wikipedia 1 Water lagoon 2 Pump house 3 Heat exchanger 4 Turbine hall 5 Production well 6 Injection well 7 Hot H 2 O to district heating 8 Porous sediments 9 Observation well 10 Crystalline bedrock Geothermie_Prinzip.svg: *Geothermie_Prinzip01.jpg: "Siemens Pressebild"

32 Deep Geothermal Heat Storage GEOTHERMAL From Wikipedia SOLAR Absorber Tubes Parabolic reflectors 26-Mar-2014 Deep reservoir 0.5 km 3 IIT-B Focal point Parabolic reflector 34

33 Geothermal - EGS It may be commercially viable, given recent developments, to exploit deep hard rock geothermal systems to Provide reliable consistent energy (power+ heat) Give the possibility of annual-scale heat storage Such a project would be at a scale amenable for communities in the north Space heat + power for all buildings Special things: e.g. greenhouses + bio-leds But the assessments and modeling remain to be done

34 Geomechanics Issues THM coupling in jointed rock masses Highly non-linear joint conductivity Conductive-convective heat transport Strong density effects if SC-CO 2 used (positive ) Channeling through dilated fractures Induced seismicity predictions No good link between MS and RM Incapable of predicting P(Mmax), recurrence Monitoring MS monitoring is not good enough Deformation monitoring is needed for geomechanics Fibre optics, tiltmeters, LIDAR (surface)?

35 Thermoelasticity & Channelling ΔT Δσ Δp massive nonlinearities Natural fractures

36 Example of s Redistribution s v, section A-A s v A s must be always constant s gain s loss B s gain T s h A zone A of -T* *-DT causes -DV B DT s h, B-B

37 Hybrid Coupled Simulations The rest-of-the-world T-p influence zone This volume is handled using special boundary elements that reduce degrees of freedom by a factor of 3 to 5 Reservoir Finite element bricks DD surface elements World = km 3 Reservoir = km 3 T-p zone = 1-5 km 3 39 of 18 Coarsely meshed T-p zone Finely meshed reservoir

38 Surface Heave from ΔT & Δp 320 mm +Δz Surface heave Δz above a SAGD project Surface heaves cannot be explained by ΔT & Δp alone: there must be shear dilation taking place. Therefore, there are massive changes in the reservoir properties k, C c,,

39 Environmental Rock Mechanics Thanks to SedHeat Organizers