GEOTHERMAL RESOURCES AND USE FOR HEATING IN EUROPE

Transcription

1 GEOTHERMAL RESOURCES AND USE FOR HEATING IN EUROPE Beata Kepinska POLISH ACADEMY OF SCIENCES MINERAL AND ENERGY ECONOMY RESEARCH INSTITUTE Krakow, POLAND Europe space heating..., UNU/GTP Workshop, Tianjin, China, May 2008

2 EUROPE - GEOTHERMAL CONDITIONS Heat flow: mw/m 2 higher values mw/m 2 in some regions Domination of geothermal water resources (low-enthalpy, T < 150 C) Paris B. Upper Rhine G. Larderello European Lowlands In. Carpathians Pannonian B. Alpine and other systems of S-Europe General distribution of main basins and geothermal resources in Europe (Antics and Sanner 2007) High-enthalpy resources (T > 150 C) : Iceland, Italy, Turkey, Greece, Azores, Main geothermal fields: - The Paris Basin, France - The Larderello region, Italy - The Pannonian Basin: Hungary, Slovakia.., - The Inner Carpathians: Poland, Slovakia - European Lowlands: Germany, Poland - Alpine and other systems of S-Europe: e.g. Bulgaria, Romania, Turkey Shallow geothermics heat of near-surface rocks an water (often T < 20ºC)

3 EUROPE - GEOTHERMAL USES, 2004 Continent Africa America Asia Europe Oceania Installed capacity MW t Direct uses Electricity generation Total production Installed capacity Total production GWh/a % MW e GWh/a % TOTAL Direct uses: 32 countries Europe dominates world top list of direct uses: Sweden (2), Iceland (4), Turkey (5), Hungary (7), Italy (8), Romania (14), Switzerland (15) Power generation: 8 states (6 based on H-E resources, Austria,Germany - L-E binary plants)

4 EUROPE TYPES OF DIRECT GEOTHERMAL USES (% used heat) Drying Industrial 0.1% uses 0.8% Aquacultures 6.20% Other 3.2% Space heating, 36.3% Bathing and swimming 35.5% Cooling 0.2% Heating greenhouses 17.7% Based on Antics and Sanner, 2007

5 EUROPE - ENERGY STRATEGY and RES Europe the largest energy importer in the world (~ 50% of energy needs) Average RES share: ~6% (0% Malta 39.8% Sweden) in 2005, 3 imperatives of EU energy strategy: - to ensure security of supply, - to ensure competitive energy prices, - to reduce the climate change impacts of the energy uses EU signed Kyoto Protocol (8% GHG drop below 1999 level in ) Key measures: Emissions trading scheme, 3 x 20 by 2020: - 20% energy consumption cut (energy efficiency), - 20% CO 2 emissions cut, - 20% RES (Directive on Promotion of RES - proposal, January 2008) Geothermal has prospective resources in several countries

6 EUROPE LEADERS IN GEOTHERMAL SPACE HEATING Space heating based on deep geothermal resources: Iceland space heating (over 98% of population), very extensive other direct uses, Turkey, France, Germany, Hungary, Italy, Romania, Other countries Space heating based on shallow geothermal resources heat pumps (GHP): Sweden the biggest geothermal heating by GHP, Switzerland, Austria, Germany, Gradual development in other countries Poland (Podhale Region) geothermal heating plant, 80-87ºC water (deep geothermal, 2 3 km), 300 TJ/a

7 EXPLOITATION OF GEOTHERMAL RESERVOIRS Exploitation of deep reservoirs Depths of the wells: max. 3 4 km Outflow water temperatures: max ºC TDS: g/dm 3 Reservoir rocks: sedimentary (carbonates, sandstones), volcanic, crystalline in same cases Wellhead Heat exchanger Exploitation in Production well Pump Injection well Closed systems: production and injection wells ( doublets, triplets ) Open systems: production wells ( singlets ) only. No injection cooled water disposed into surface water or used for other purposes Geothermal aquifer 1 geothermal aquifer 7 heat exchanger 2 production well 8 heating water pipeline 4 pump 9 geoth. water pipeline 5,11 wellhead 10 injection pump 6 filters 12 injection well

8 Exploitation of shallow resources Heat energy extracted from shallow water/ground through heat pumps Significant development e.g. in Sweden, Switzerland, Germany, Austria Very prospective line of geothermal use 1 kwh electric energy to drive compressor gives ca. 2 4 kwh thermal energy ENHANCED GEOTHERMAL SYSTEMS /HOT DRY ROCK Deep (3-5 km) hot (>150 C) rocks devoid of waters: Horizontal collector - low heat source for heat pump Artificial fracturing of rocks, injecting water through the wells. Heated water/steam (to >100 C) is pumped out and used for power generation and/or for heating. Instead of injecting water a bore-hole heat exchanger can be used to extract rocks heat. R&D projects in France, Germany, Switzerland. Artur Karczmarczyk (PI 06/2003) Vertical collector (bore-hole) low heat source for heat pump

9 SPACE HEATING SYSTEMS IN EUROPE SELECTED EXAMPLES

10 FRANCE Two main areas of geothermal exploitation for heating: Paris Basin The Paris Basin (carbonate reservoir) The Aquitane Basin (sandstone reservoir) Aquitane B. Geothermal waters exploited in closed systems of km wells France a leading country in geothermal heating in Europe. Good example to follow.

11 Space heating in Paris Basin 34 geothermal heating plants Based on well doublets/triplets drilled in MWt installed capacity Gas-cogeneration in same cases 1, 000 GWh/a - supply 150,000 equivalent dwellings (70 m 3 each) Savings 500,000 tonnes of CO 2 Geothermal heating plants in the Paris Basin, France (source: BRGM)

12 W ANGERS TOURS ORLEANS (PARI S) MEAUX MELUN REIMS VERDUN METZ 0m 1000 Cr T J2 Cr J3 J 3 T isotherm60c 0 0m 2000 J Stratigraphicboundaries isotherm10c 0 A sketch cross-section through the Paris Basin showing the location of Dogger geothermal aquifer The Paris Basin: Aquifer: limestones (Dogger- Middle Jurassic) Outflow water temperatures: 60-80ºC TDS: 5-35 g/dm 3, gases (H 2 S), Cl-Na water types Corrosive waters ( need for injection of spent water back into the aquifer) ) Geothermal doublet, Paris Basin

13 1 Production well 2 Submersible pump 3 Injection pump 4 Injection well 5 Heat exchanger 6 Peak gas boiler 7 Heating network to / from receivers 8 Sub-station at heat receiver 9 Geothermal aquifer (Dogger) The Paris Basin, France main parts of geothermal heating systems (source: BRGM)

14 French geothermal space heating story peaking period of development (following the 1 st oil crisis): 74 plants on-line: 54 in Paris Basin, 15 in Aquitaine and 5 in other regions decrease in development: Drop in energy prices, technical difficulties (scaling, corrosion, colmatation) projects to solve economical and technical problems: (well rehabilitation, inhibitors, soft acidizing - long-term preventive methods for mitigating or avoiding corrosion and scaling) - the stability of geothermal systems operation was achieved From optimising geothermal heating networks and connecting new clients Today - 61 plants on-line, 34 in the Paris Basin, Some new wells being drilled growing interest of local municipalities (eg. Orly/Paris) France - good technologies, legislation and economic conditions facilitating long term geothermal plants operation and investments (e.g. The Guarantee Fund to minimise the risk connected with drilling the 1 st well and worsening exploitation parameters with time)

15 Germany geothermal heating based on deep and shallow resources Great dynamics of development >140 direct use installations (177 MWt) space heating, greenhouses, spas Several heating plants based on deep aquifers: - N-Germany (sandstones) - S-Germany /Munich area (carbonates) - Upper Rhine Graben Main parameters: - Depths of wells: to km - Water temperatures ºC - TDS variable: <1-220 g/dm 3 - Flowrates variable: max m 3 /h - Thermal capacities variable: MW t 15 projects planned for (some on-line in 2008) Shallow geothermal, 2007: Heat pumps: > 30,000 installations (> 400 MWt, >2,200 TJ/a)

16 Germany - geothermal heating, cont. Neustadt Glewe, N-Germany: heating plant based on deep sandstone reservoir: In operation since 1995 Total thermal capacity MW t : 6 MW t geoth MW t gas boilers Depth of aquifer Lithology Reservoir temperature Number of wells Distance between wells Water flow rate Injectivity Wellhead temperature TDS Chemical composition m Sandstones 98ºC (2223m) 2 (1 production, 1 injection) m 183 m 3 265m ºC 220 g/dm 3 Main ions: Na and Cl ca. 10% of gas: CO 2, N,CH 4. From 2003: binary power generation (0.3 MW e ), Organic Rankine Cycle ORC

17 Injection pressure (bar) Problems during exploitation: 1. Corrosion and scaling due to high TDS and gas content: Limitation: Specific materials applied: glass-fibre tubes, resin-lined steel tube parts Inertisation by nitrogen loading to the systems during operation breaks 2. Increase of the injection pressure during exploitation: The soft acidizing method implemented (1999) - the injectivity index considerably increased and the injection pressure dropped significantly State before soft acidizing State after soft acidizing Water flowrate (m³/h) Initial state

18 METHODS OF COOLED GEOTHERMAL WATER DISPOSAL FROM HEATING SYSTEMS INJECTION, NO INJECTION Reservoir rocks Example Method of exploitati on TDS, g/dm 3 Wellhead temperatureº C Way of cooled water disposal Carbonates Sandstones Paris Basin France Podhale region Poland Neustadt-Glewe Germany Mszczonow Poland Slomniki Poland Doublets Injection Doublets Injection Doublet Injection Singlet No injection, Cooled water for drinking Singlet No injection, Cooled water for drinking Majority of systems geothermal water after heat extraction injected back to reservoir (to mantain pressure, volume of water and long-term sustainable exploitation) Same cases - spent water not injected but applied for other needs, e.g. pools or balneotherapy (most common), cooled water used for drinking (TDS<1g/dm 3 )

19 ECOLOGICAL BENEFITS OF GEOTHERMAL HEATING m g/m³ 40,0 35,0 35,1 32,6 32,4 35,1 Start of gas-fired Peak Load Plant 30,0 25,0 20,0 28,0 23,6 17,8 32,6 m g/m³ av. SO ,0 Example the Podhale project, Poland, 2007: 15,0 10,0 5,0 0,0 15,2 13,0 11,9 10, Limitation of SO 2 emissions thanks to geothermal space heating introduction in Zakopane (main city, population 30,000, 3 mln tourists/a): 10 3 T CO 2 Average annual SO 2 concentrations (average yearly drop by 40-50%) Before 1998 coal-based heating 1998/1999 Gas Peak Load launched 35,0 30,0 25,0 20,0 15,0 10,0 5,0 0,0 4,9 5,2 12,7 18,9 22,1 23,5 24,6 25,2 29,3 2001/2002 1st geothermal heating season in Zakopane Connections underway (2008) Year Yearly CO 2 limitations thanks to geothermal heating

20 SHALLOW GEOTHERMAL RESOURCES Geothermal heat pumps Switzerland Switzerland geothermal direct uses, 2006 (L. Rybach & R. Minder, 2007) Type of use Installed capacity, MW t Annual energy use, TJ/y Heat pumps with BHE Groundwater-based HP Geostructures, tunnel waters (HP) Deep aquifers for district heating Spa, wellness facilities TOTAL Heat pumps share 85% 75% Switzerland a prominent world rank in installing and running GHP 2006 over 1000 km shallow wells drilled for BHE (!) Constant increase in installations of new GHP CO 2 reduction ca. 400,000 tons /y

21 UNDERGROUND MINES POTENTIAL GEOTHERMAL HEAT RESERVOIRS Warm water pumped out from coal mine, Poland Mines that have extracted fossil fuels in the past can produce clean and renewable geothermal energy Temperatures of water in mines (coal, ores) reach up to o C at depths of km Heat contained in water pumped out from abandoned coal mines is used via heat pumps based installations e.g. in Canada, Germany, Scotland Next coal and ore mines in Europe, e.g. Netherlands, Germany, Poland - R&D and implementation projects EU-funded Minewater project: warm water from abandoned coal mine will be soon used for heating in Herleen, Netherlands

22 FUTURE PROSPECTS OF GEOTHERMAL HEATING Progress in existing and in new technologies and types of uses: - improved and innovative methods in exploration, technologies, materials, - construction of new district heating networks, - improvement of existing networks and plants, Heating systems integrated with other RES and fossil fuels, co-generation plants (heat + some electricity), Increase in efficiency and technologies in heat pumps (shallow geothermal), The progress in geothermal heating shall be also facilitated by better legal and economical measures at the levels both at the European Union and particular European countries.

23 CLOSING REMARKS Numerous space heating systems based both on deep and shallow geothermal resources have been successfully operated in Europe, The variety of reservoir conditions and methods of exploitation proves the variety of ways in which geothermal energy can be used for space heating, Space heating will remain number 1 among geothermal uses in Europe, The continent has collected many experiences, achieved significant positive results, owns modern and reliable technologies, These make Europe a good example to follow as far as geothermal heating is concerned.

24 Geothermal Spring of Chopin, Poland THANK YOU VERY MUCH FOR THE ATTENTION

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26 GEOTHERMAL IN ENERGY POLICIES, EU, cont. The Kistelek Declaration, 2005 to promote wider geothermal use for heating in Europe. Adopted by geothermal experts. Points out good geothermal resources (waters) which can provide considerable share in heating sector. Necessary better legislation and economic systems to ease geothermal use. Support of geothermal research, R&D, projects i.e. donations or subventions provided by the national and EU public sources devoted for RES sector, Environmental protection, etc. Guarantee Funds in some states (France, Germany) to limit the risks of drilling 1st geothermal well or of worsening exploitation parameters EU-Framework Programmes: 7 th FP for for R&D in many fields of science and economics. Important theme: Energy RES (geothermal) Although not treated as a number 1 among RES by politicians and decision makers, geothermal energy can, and should, achieve a significant share in many local energy markets

27 Exploitation of deep reservoirs Problems related to sedimentary reservoirs exploitation: Productivity and injectivity changes Colmatation, plugging of near-hole zone, sanding-up Scaling, corrosion, etc. Methods fora successive treatment and maintenance implemented in several countries: France - carbonate reservoirs Germany sandstone reservoirs

28 Problems: 1. Corrosion and scaling due to high TDS and water composition Limitation: Specific materials applied: glass-fiber tubes, resin-lined steel tube parts Inertisation by nitrogen loading to the systems during operation breaks 2. Increase of the injection pressure during exploitation Caused by sedimentation of solid particles on the filter section of injection well (mostly acid-soluble iron hydroxides and aragonite) The soft acidizing method implemented (1999): Highly-diluted HCl added to lower the ph (to 2 3 ph) of injected geothermal water: For 2 days, ca. 4 m 3 of 15% HCl was systematically added to injected geothermal water (total water volume was 1600 m 3 ) Result - the injectivity index was considerably increased, and the injection pressure dropped significantly

29 UNDERGROUND COAL MINES AS POTENTIAL GEOTHERMAL HEAT RESERVOIRS Mines that have extracted fossil fuels in the past can produce clean and renewable geothermal energy Temperatures of water in flooded mines reach o C at depths of km Heat contained in water pumped out from abandoned coal mines is used via heat pumps based installations e.g. in Canada, Germany, Scotland Sketch of water reservoir in the mine workings after extraction of coal seam (marked as a black layer) and caving in of the roof. Arrows q mark heat inflow Next coal and ore mines in Europe, e.g. Netherlands, Germany, Poland - are subjects of reservoir studies and implementation projects (EU-funded Minewater project: warm water from mine will be used for heating system in the town)

30 EUROPE GEOTHERMAL CONDITIONS Europe: temperatures at the depth of 1km (Geothermal Atlas of Europe, 2002)

31 toheat receivers BAŃSKA IG-1 BIAŁY DUNAJEC PAN-1 [m] 0 Main Geothermal Heat Exchanges Station 500 injection well 1000 production well geothermal aquiferl [m] 1500 METHOD OF GEOTHERMAL WATER EXPLOITATION AND HEAT EXTRACTION Closed system of geothermal water exploitation : 1 production and 1 injection well 2 plate heat exchangers Capacity 4 MW t, ca. 30 TJ/y Production m 3 /h of C water Heat supply to 195 houses and cascaded uses Geothermal doublet working in , PAS MEERI Since 2001: 2 production and 2 injection wells. Heat exchangers station (target 60 MW t ) Max. production 670 m 3 /h of C water

32 . The practical use of underground mines heat has not entered the application stage yet. Among the main obstacles are problems with restructuring the coal industry branch Proposal of practical implementation - the use of warm water pumped out from selected coal mine for stenothermal fish farming (African catfish): Parameters of water pumped out of the mine: - Flowrate m 3 /h - Temperature - ca. 20ºC Fish farm sited near the shaft, with which water is pumped out to the surface Heat recovered through heat pumps Yearly production could reach over 110 tons of fish Installation could be constructed within less than 10 months It would be profitable, and the simple payback period was estimated for 5 years

33 Thermal energy extracted from the brine can be used: Directly - floor heating, swimming pools, soil heating cultures Indirectly - through the heat pumps for space heating and tap water Potential heat consumers should be located close to the energy source (diapires). Such situation exists in several places where moderate local heating systems can be developed Before starting thermal energy production from a specific diapir, economic feasibility analysis has to be made The subject to be continued

34 SALT DIAPIRES POTENTIAL FUTURE GEOTHERMAL HEAT SOURCES Cr Q T T P J 80ºC 50ºC A cross-section through Poland showing the salt domes (diapires) penetrating younger rocks Salt diapires specific tectonic structures formed by pushing plastic Permian saline formations upward to the surface owing to the pressure of a few kilometre layer of younger sedimentary rocks (from Triassic to Quaternary) Roots of diapires - 5 to 8 kilometres b.s.l. Roofs (gypsium caps) some hundred some dozen metres from the surface

35 Thermal properties of salts and salt structures Thermal gradients and conductivities within salt dome and surrounding rocks J 0,6 1,0 Tr+Q P 0,8-3,8 2,9 6,4 2,9 Tr+Q P 4 5 J High thermal conductivity: 6-7 W/mK, 2-3 higher than neighbouring rocks (limestones, sandstones, siltstones) Diapires form natural positive thermal anomalies and migration paths - thermal bridges ( chimneys ) - facilitating heat transfer from greatest depths to the surface Poland - salt is extracted by leaching - temperature of pumped brine on the surface C Brine is a carrier both of mineral substance (salt) and geothermal heat Heat extracted from brine can be used for heating (heat pumps), swimming pools, soil heating cultures J

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37 Geothermal doublets operating in the Paris Basin, 2008 Years of drilling Number of doublets working Number of doublets working Vertical wells, depths, m Deviated wells, Depths, m Water flowrate, m 3 /h Wellhead temperatures, ºC Method of production Remarks production 40-60ºC injection Submersible pumps Artesian Gascogeneration in same cases The stability of geothermal systems operation was achieved thanks to introduction of effective preventive methods aimed at mitigating and avoiding well damages, corrosion and scaling thus to maintain production and injectivity indices. The methods elaborated and successfully implemented - the soft acidizing and injecting the inhibitors. They can be also applied in other sedimentary systems.

38 CONTENTS EUROPE GEOLOGICAL AND GEOTHERMAL CONDITIONS GEOTHERMAL USES, 2004 GEOTHERMAL IN ENERGY POLICIES METHODS AND TRENDS OF GEOTHERMAL EXPLOITATION AND USE EXPLOITATION OF GEOTHERMAL SYSTEMS - MAIN OPTIONS DEEP RESOURCES IN SEDIMENTARY FORMATIONS France, Germany SHALLOW GEOTHERMAL RESOURCES Switzerland, Poland CONCLUSIONS