IGD Greece 2002 Aristoteles University, Thessaloniki Possibilities for Heating and Cooling through Underground Thermal Energy Storage in the Mediterranean area Burkhard Sanner and Halime Paksoy Institute of Applied Geosciences Justus-Liebig-University, Giessen, Germany Chemistry Department Çukurova University, Adana, Turkey
Underground Thermal Energy Storage! Because of the climatic conditions around the Mediterranean sea and on the islands, cooling is the premier task of building thermal energy systems.! The systems used currently almost all depend on refrigeration cycles driven by electricity (compression chillers) or high-temperature heat (absorption chillers). The result is a tremendous need for energy just for space cooling.! In places where at times enough cold (winter air, rivers from mountains, etc.) exist, Underground Thermal Energy Storage is a very effective method to save energy.
Underground Thermal Energy Storage Aquifer Storage (ATES) Borehole Storage (BTES) Cavern Storage (CTES) Alternatives of Underground Thermal Energy Storage
BTES: Borehole Heat Exchanger Double-U-tube borehole heat exchanger (BHE), (Example of the type made by HAKA, Switzerland)
BTES: DFS, Langen Headquarter of the German Air Traffic Control, architects s concept Total area 57.800 m 2 Cooling output from BHE 340 kw Heating Output from HP 330 kw 154 Borehole Heat Exchangers (BHE), each 70 m deep
BTES: DFS, Langen 1000 800 600 Cooling with chillers Heat from District Heating Cooling with Borehole HX Heating with Heat Pump 400 200 0 200 400 600 800 1000 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Heating and cooling demand, data from simulation
BTES: DFS, Langen District Heating HEATING COOLING Borehole heat exchangers Chiller mechanical cooling free cooling Heat Pump Thermoceilings static Heating Air heating Pre-heating Ventilation air Pre-cooling Air cooling Cooling ceilings Schematic of the heating- and cooling concept
BTES: DFS, Langen Design: Determination of Ground Thermal Conductivity using Thermal Response Test Equipment on site in Langen (Photo: UBeG)
BTES: DFS, Langen Chinese delegation on the construction site 3 x 18 BHE (54) 0 5 10 m Placement of Borehole Heat Exchangers
BTES: DFS, Langen 900000 800000 700000 600000 Energy cost Maintenance cost Investment cost (LEO: Low Energy Office) 500000 400000 300000 200000 Annual total cost (after Seidinger et al., 2001) 100000 0 LEO DFS LEO without Borehole HX Standard WSO 95
BTES: Richard Stockton College, NJ, USA Large BTES in warmer climate close to the Atlantic seaside 400 BHE each 130 m deep Total >5 MW cooling output
BTES in Neckarsulm-Amorbach Buffer tank 100 m³ Heating plant Solar collectors 2.700 m² Underground Thermal Energy Storage, Loading by Solar Thermal Energy Auxiliary burner Duct heat store 20.000 m³ Heat distribution network Borehole Heat Exchanger Storage (BTES) graphic ITW, Uni Stuttgart
Pilot store 36 Boreholes 4.300 m³ 1997 2. Extension; 528 Boreholes 63.000 m³, 2001 1. Extension 168 Boreholes 20.000 m³ 1999 M13 M10 BTES in Neckarsulm-Amorbach M15 M09 M11 M18 M08 M12 M07 M06 M05 M04 M14 M17 M02 M03 M01 M16 Underground Thermal Energy Storage, Loading by Solar Thermal Energy
BTES in Neckarsulm-Amorbach Ground surface: 203 m above sea level -5 m -35 m -40 m ca. -68 m Marl Dolomite Marl Limestone Loess Quaternary Karn (Gipskeuper) Ladin (unt. Keuper) Ladin (Muschelkalk) Geological cross-section at the Neckarsulm BTES site Geology: - Mean underground thermal conductivity until 35 m depth λ = 2 W/m/K - Mean volumetric heat capacity of the ground c v = 3 MJ/m³K - Groundwater level is between 10 and 15 m below ground level - The layers with marls have very low hydraulic conductivity (k f 5 10-8 m/s). - The limestone below 70 m depth is a major drinking water reservoir of the area, thus it was not allowed to be tapped.
BTES in Neckarsulm-Amorbach Temperatures in the ground (center), after data from ITW, Stuttgart Temperature [ C] 60 55 50 45 40 35 30 25 20 15 10 0 m=top of store=3 m below ground surface M24 (10m) M32 (0m) M34 (10m) M145 (20m) M146 (30m) M147 (32m) M148 (35m) M149 (40m) 1.1.99 2.5.99 31.8.99 30.12.99 29.4.00 28.8.00 28.12.00 28.4.01 27.8.01
ATES: Principle of a cycling store winter ATES (cycling) summer aquifer aquifer warm well cold well warm well cold well Loading and unloading operation of a cyclic ATES
ATES: SAS, Solna Schematic of ATES plant for SAS headquarters, Solna, Sweden Ventilation air HP glycol circuit Heat exchanger (heating, winter) DHW Building cooling water circuit Heat exchanger (cooling, summer) cold well (2-12 C) Summer Winter warm well (8-15 C) Aquifer (esker)
ATES in Rostock-Brinckmannshöhe 0 5 10 15 20 25 30 35 40 45 [ C] 50 5 depth [m] 10 15 20 25 30 35 aquifer 01.01.01 01.02.01 01.03.01 01.04.01 02.05.01 02.06.01 02.07.01 02.08.01 02.09.01 02.10.01 02.11.01 Underground Thermal Energy Storage, Loading by Solar Thermal Energy Typical temperature behaviour within the aquifer (summer 2001; after data from ITW, Univ. Stuttgart)
ATES in Turkey: Supermarket Yonca, Mersin Supermarket Yonca, Mersin, in late fall 2001
ATES in Turkey: Supermarket Yonca, Mersin Number of wells 2 Depth of wells Distance between the wells Type of aquifer: Flowrate Cooling load 100 m 81 m sandstone 4 l/s (14.4 m 3 /h) 2401.5 kwh/day Basic data for ATES in Supermarket Yonca, Mersin System is working satisfactorily, but has owerflow problems in both wells. Problem should be fixed by the end of this season
World-wide ATES examples Name City Cooling output (kw) Cold source Year CERA Bank Leuven, B 1000 cooling tower 1996 Scarborough Center Toronto, Can 1500 HP, cooling tower 1984 Carleton University Ottawa, Can 2500 HP 1988 Perscombinatie Amsterdam, NL 450 cooling tower 1987 Groene Hart Hospital Gouda, NL 1100 ventilation air preheating 1992 IBM office Zoetermeer, NL 900 cooling tower 1993 Jaarbeurs Utrecht, NL 2700 ventilation air preheating 1993 Stadhuis Den Haag, NL 3300 cooling tower 1994 Rijksmuseum Amsterdam, NL 900 cooling tower 1994 Schiphol airport Amsterdam, NL 2400 cooling tower 1995 SAS Frösundavik Solna, S 2000 HP, ventilation air pre-heating 1987 Triangeln Malmö, S 1500 HP 1990
ATES for the Parliament: Deutscher Bundestag, Berlin graphic GTN Heat- and Cold Storage, heat source waste heat from Combined Heat- and Power-Generation (CHP) during summertime
ATES for the Parliament: Deutscher Bundestag, Berlin Alsenblock Absorption HP Luisenblock Alsenblock Luisenblock Heat-powerco-generation Heat-powerco-generation Reichstagsgebäude Absorption HP Reichstagsgebäude Dorothenblöcke Dorothenblöcke Heating- and Cooling-Network for the Parliament Buildings Heat storage Cold storage
ATES for the Parliament: Deutscher Bundestag, Berlin Biodiesel Heating- and Cooling- Network for the Parliament Buildings Wärme Strom Kraft-Wärme- Kopplung Kältespeicher ca. 60 m unter GOK Energy demand of the Parliament buildings (from planning) Rupelton (Aquitard) Electricity: 8.600 kw Heat: 12.500 kw Cold: 6.200 kw Wärmespeicher >300 m unter GOK
Underground Thermal Energy Storage Cold sources and opportunities in the Mediterranean! The main cold source can be the ambient air in cold winter nights, as e.g. shown for a project in Egypt (Abbas et al., 1996; Abbas, 1998), in both alternatives! In certain locations, streams from the mountains bring cold water in winter and spring and can be used as cold sources. An ATES project based on water from Seyhan river was studied for the new extension of the academic hospital of Çukurova University in Adana, Turkey.
Conclusions! Studies have shown that UTES systems for cooling can be applied in the Mediterranean area! Within a collaborative project of the IEA, a study on the UTES potential in Turkey was prepared (Annex 8 of the Energy Conservation through Energy Storage Implementing Agreement)! From the experience in other areas, and from the Turkish potential study it can be concluded that the relevant geological conditions for UTES systems can be found frequently around the Mediterranean Sea, and also that for most underground situations a suitable UTES option (ATES, BTES, hybrid) can be adapted.