4TH INTERNATIONAL CONFERENCE ENERTECH 2009 ATHENS,, 23 242 OCTOBER 2009 COGENERATION OF HEAT & POWER (CHP) FROM MEDIUM ENTHALPY GEOTHERMAL FLUIDS M. FYTIKAS & M. PAPACHRISTOU
Medium Enthalpy Geothermal Potential in Greece Temperature = 90 150 150 C Utilisation: : CHP & Direct Use (heating, cooling, industrial and agricultural use, etc) Location: : Sedimentary basins of Northern Greece & North Central Aegean islands (Samothrace, Lesvos, Chios etc)
North Eastern Greece
Evros Basin Aristino (Alexandroupolis) geothermal field T>50ºC C at 200m and T>86ºC C at 360m Well AA-1: 72.3ºC C at 360m (geothermal gradient=160ºc/km) Well AA-1P: 51ºC C at 216m (geothermal gradient =180ºC/km) Well AA3: 86.8ºC C at 340m (geothermal gradient =210ºC/km) Flow rate : 150m 3 /h
Xanthi Komotini Basin Nea Kessani geothermal field The maximum temperature registered within the (relatively shallow) wells is 82 C. The main hot reservoir is located at shallow depth 150 400m with temperatures between 75 80 C. At 1000m temperature may reach up to 110 C
Nestos Basin Eratino Chrysoupolis Intense geothermal anomaly with gradient between 80 100 ºC/km. Temperatures of 60.9 ºC C at 430m and 69.7 ºC C at 530m were recorded in exploration boreholes Artesian flow rate 200 m 3 /h, 75oC from 700m deep well Temperature of 122 ºC C at 1377m were recorded in a exploration well (N 1P), average gradient 78ºC/km.
Strymonikos Gulf Akropotamos (Kavala) geothermal field AKP 1: Τ=83 C at 270 m; flow rate 150 m 3 /h AKP 3: Τ=90 C at 515 m; flow rate 200 m 3 /h AKP 4: Τ=48 C at 180 m; flow rate 40 m 3 /h 83 o C + CO 2 150 m 3 /h High Concentration of CO 2
Chios Samothrace Samothrace Lesvos 3 shallow exploration drillholes: (<120m): 80-100 100 C,, 150m 3 /h Geoth.field Polichnitos Nenita area: : 5 of the expl. Argennos wells reached at temp. up to 88 C Stypsi Napi Temperature ( C) 67 92 86 42 110
Balneotherapy Pools Heating panels Floor panels Hot water Absorption cooling Geothermal heat pumps Deicing Greenhouse heating Soil warming Fruit & vegetable drying Cleaning animal shelters Food processing Aquaculture Water desalination Biological mud digestion Oil recovery Wool cleaning Wood drying Salt extraction Paper & wood processing Balneotherapy, pools Space heating/cooling Agri-business uses Industrial uses Convectional power plants Bunary cycle plants 0 50 100 150 200 250 300 350 Temperature ( o C) The (modified) Lindal diagram, showing the possible use of geothermal fluids at different temperatures
Power Generation from Medium Enthalpy Geothermal Fluids Binary (or Organic Rankine) ) Cycle (ORC) power plants using fluids of 85-175 175 C (USA, Philippines, Hawaii islands, Portugal-Azores, Germany etc.)
Binary Power Plant in Hawaii 1990: The P.G.V. acquired the permit for a 60 MW power plant in Puna 1993: operation of a 30 MW plant It covers the 20% of the island needs 8 MW expansion The opposition of the inhabitants was very strong in the beginning (mostly for religious and environmental reasons) Today it is the most reliable power source Total reinjection of the fluids
Binary power plant in Mexico Mammoth Pacific binary power plants at the Casa Diablo (USA) geothermal field
Nevada-Blue Mountain California - East Mesa
Utah geothermal project with a series of small (250kW e ) binary modular units
Combined electric and direct geothermal cascade uses 120 o C 150 o C
Altheim (Austria) CHP System
Neustadt Glewe (Germany) CHP System 1995: District Heating (11MW th ) 2003: CHP (ORC 210kW e ) Temperature: 98 C
Geothermal power plant in Svarstengi (Iceland) & Blue Lagoon Spa resorts
Geothermal power plant in Wairakei (New Zealand). The geothermal fluids cascade to a shrimp farm pond
Industrial Applications of medium enthalpy geothermal energy Vegetable dehydration plant in Nevada: one well with 132 C, 113ton/day of dehydrated onions (May October), celery in March April and carrots from November to January. 75 employees all year round.
Tomato dehydration with geothermal energy in Neo Erasmio (Xanthi) Geothermal Fluid entry Geothermal Fluid Exit
Milos island (Greece). Proposed medium enthalpy (85 98oC) geothermal energy utilisation for power generation, desalination and other uses
Reykjavik 1932: Use of conventional fuels for heating Reykjavik today: Utilisation of geothermal energy for district heating 89% of the heating requirements in Iceland are covered by geothermal energy
Heat exchangers Distribution pumps Production well & Distribution networks
The first geothermal district heating system in USA
Geothermal greenhouses next to geothermal power plant in Gufudalur, Hveragerði (Iceland) Geothermal greenhouses in Idaho (USA)
Aquaculture installation at Vistonida Lake with low temperature (36oC) Possible final step in cascade utilisation of Geothermal Cogeneration
Heating of modern greenhouses with cogeneration (Greece)
Accelerated Growth of Asparagus with Geothermal Soil Heating (210.000m2 in Greece)
COGENERATION OF HEAT AND POWER (CHP) FROM MEDIUM ENTHALPY GEOTHERMAL FLUIDS EXPECTED TEMPERATURE: 150 ο C at 1600 1700 1700 m EXPECTED FLOWRATE: 50 kg/s (180m3/h) GEOTHERMAL CAPACITY: 25 MWt CONVERT TO ELECTRICITY: 4 MW e (binary cycle technology) RESIDUAL THERMAL CAPACITY: 21 MWt POWER PLANT COST 2 GEOTHERMAL WELLS + INSTALLATIONS 6.000.000 5.000.000 ANNUAL POWER PRODUCTION: 28.000 MWh/year (use factor 80%) INCOME FROM ELECTRICITY SALE: 2.24 240.000 ( ( 80/MWh MWh) GREENHOUSE HEATING: ca 260.000m 2 THERMAL ENERGY: 73.000 MWht/year ASPARAGUS SOIL HEATING: ca 600.000m 2 THERMAL ENERGY: 12.500 MWht/year TOTAL YEARLY INCOME INVESTMENT AMORTISATION APPROX. INCOME (vs( CHP Nat. Gas): 2.900.000/year APPROX. INCOME: 500.000/year 5.640.000/year < 2 YEARS
CONCLUSIONS According to world wide experience and examples, the ORC power generation projects can easily achieve economic viability when a heating segment is added to the utilisation grid. Heat and power cogeneration can result in significant cost savings and in the reduction of the payback period. The important medium enthalpy geothermal potential in sensitive areas of Greece, in combination with available and mature technology solutions, can contribute significantly to the development of local communities and improve national energy equilibrium Minimum to zero environmental impacts
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