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INTERNATIONAL SUMMER SCHOOLon Direct Application of Geothermal Energy

Under the auspice of theDivision of Earth Sciences

GEOTHERMAL ENERGY IN MACEDONIA, STATE-OF-THE-ARTAND PERSPECTIVES

Mirjana Gorgieva1; Kiril Popovski2; Dusko Gorgiev3;

1 St.Ciryl & Methodius University, Faculty of Science and Mathematics, Gazi baba bb, 1000 Skopjemiragor@iunona.pmf.ukim.edu.mk

2 St.Kliment Ohridski University, Faculty of Technical Sciences, Ivo Ribar Lola bb, 7000 Bitolaisskiril@sonet.com.mk

3 Domis, Mito Hazivasilev Jasmin 20/3, 1000 Skopjedomis@unet.com.mk

Fig.1. Map of MacedoniaABSTRACT

The geothermal zone spread in Mace-donia is associated with geothermal manif-estations (mainly hot springs and wells withtemperature from 20-790C) at more than 50localities.

It is believed that only low temperaturefields exist. Almost all hydrogeothermal sys-tems are related to an ancient subduction

zone of Jurassic age, along the Rodopianmass and Dinarides known as Vardar tecto-nic unit. The most important hydrogeother-mal systems are in the Skopje valley, Ko-chany valley, Strumica valley, Gevgelia val-ley, and Kozuf Mountain and Kratovo-Zletovo volcanic area.

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1. Q-sediments;; 2.Pg;Ng-send, clay; 3. Pg;Ng-tuff; 4. Pg-Ng-dacite and andesite; 5.T-marbeled lime-stone; 6 J-gabros.; 7. J-peridotites; 8. K-flycsh 9. Pz-granites 10. Pz-slates and other metamorphic rocks 11. Pc- marbles; 12. Pc-gneisses

GEOLOGICAL MAP OF MACEDONIA

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ZEMAKPhone-Fax: + 389 (091) 119 686 - Cellular: + 389 (070) 262 044 - E-mail: isskiri@soros.org.mk

Mira gorgievaEftim MicevskiKiril PopovskiSkopje, 2000

Fig.2. Geological map of Macedonia

GEOLOGICAL FRAMEWORK ANDTECTONIC SETTING OF MACEDONIA

In the territory of Macedonia rocks ofdifferent age occur, starting from Precam-brian to Quaternary. Almost all lithologicaltypes are represented. The oldest, Precam-brian rocks, con-sist of gneiss, micaschists,marble and orthome-tamorphites. The rocksof Paleozoic age mostly belong to the typeof green schists, and the Mesozoic ones arerepresented by marble limestones, acid,basic and ultrabasic magmatic rocks.

The Tertiary sediments consist of flyschand lacustrine sediments, sandstones, lime-stones, clays and sands.

With respect to the structural relationsthe territory of Macedonia can be dividedinto six geotectonic units: The Cukali-Krastazone, West Macedonian zone, Pelagonianhorst anticlinorium, Vardar zone, Serbo-Macedonian massif and the Kraisthidezone, Fig.1. This tectonic setting is basedon actual terrain and geological data withoutusing geotectonic hypothesis (Arsovski,

1998). First four tectonic units are parts ofDinarides, Serbo-Masedonian mass is partof Rodops and the Kraisthide zone is part ofKarpato-Balkanides distinguished on theBalkan peninsula as geotectonic units offirst stage.

GEOTHERMAL BACKGROUND

The territory of the Republic of Ma-cedonia belongs to the Alpine-Himalayanzone, with the Alpine subzone having nocontemporary volcanic activity. This partstarts from Hungary, across Serbia, Mace-donia and north Greece and stretches toTurkey. Several geothermal regions havebeen distinguished including the Macedo-nian region, which is connected to the Var-dar tectonic unit. This region shows positivegeothermal anomaly hosting differentgeothermal systems, Fig.3. The hydrogeothermal systems, at themoment, are the only systems that areworth investigation and exploitation.

In the Republic of Macedonia there are18 geothermal fields with more than 50

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thermal springs, boreholes and wells withhot water. These discharge almost 1.400 l/swater flow with temperature of 20-79 0C.Some of this water is used for heating ho-tels and greenhouses, some for balneologypurposes and some discharge without beingused.

The hot waters in Macedonia are mostlyhydrocarbonate according to their dominantani-on, and mixed with equal presence of

Na, Ca and Mg. The dissolved mineralsrange from 0.5 to 3.7 g/l.

All thermal waters in Macedonia are ofmeteoric origin. Heat source is the regionalheat flow, in the Vardar zone is about 100mW/m2 and crust thickness 32 km.

GEOTHERMAL FIELDS IN MACEDONIA

There are 18 localities where geother-mal fields occur and geothermal energy is inuse for different proposes, Table 1. Themost known areas are listed below.

Fig.3. Map of regional tectonic setting ofMacedonia (Arsovski, 1998) with maingeothermal (low temperature) areas

Kochani valley

The main characteristics of the Kochanivalley geothermal system are: presence oftwo geothermal fields, Podlog and Istibanja,without hydraulic connection between them;a primary reservoir is build by Precambriangneiss and Paleozoic carbonated schists;

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the highest measured temperature in Ma-cedonia of 790C obtained by drilling; thepredicted maximum reservoir temperatureabout 1000C. The Kochani geothermal sys-tem is the best investigated system in Ma-cedonia. There are more than 25 boreholesand wells with depths of 100-1.170 m.

The usage of thermal waters in Kochanivalley is given in Table 1.

Strumica valley

There is one geothermal field in theStrumica valley, Bansko in the village Ban-sko.The main characteristics of this fieldare: the recharge and discharge zone occurin the same lithological formation-granites;there are springs and bore-holes withdifferent temperature at small distances;maximum measured temperature is 730C;the predicted maximum temperature is1200C (Gorgieva, 1989); the reservoir in thegranites lies under thick Tertiary sediments.Bansko geothermal system has not beenexamined in detail apart the drilling ofseveral boreholes with depths of 100-600m.Thermal water is use for greenhouse andheating, Table 1.

Gevgelia valley

There are two geothermal fields in theGev-gelia valley: Negorci spa andSmokvica.The discharge zone in bothgeothermal fields are fault zones in Jurassicdiabases and spilites. Although these twofields are separated by several km there isno hydraulic connection bet-ween them,despite intensive pumping of ther-malwaters. The maximum temperature is 540C,and the predicted reservoir temperature is75-1000C. The geothermal system in theGevgelia valley has been well studied by 15boreholes with depths between 100-800 m.

Thermal wa-ters are used as listed in theTable 1.

Skopje valley

There are two geothermal fields in theSko-pje valley: Volkovo and Katlanovo spa.There is no hydraulic connection betweenthem. The main characteristics of theSkopje hydrogeo-thermal system are:maximum measured temperature of 54.4 0Cand predicted reservoir temperature, bychemical geothermometers, of 80-1150C(Gorgieva, 1989); the primary reser-voircomposed of Precambrian and Paleozoicmarbles; big masses of travertine depositedduring Pliocene and Quaternary periodalong the valley margins. There are onlyfive borholes with depths of 86m inKatlanovo spa, 186 and 350 m in Volkovoand 1.654 and 2.000 m in the middle part ofthe valley. The last two boreholes arewithout geothermal anomaly and thermalwaters because of their locations in Tertiarysediments with thickness up to 3.800 m.

PERSPECTIVES FOR GEOTHERMALFIELDS IN MACEDONIA

Even with a long tradition in geothermalenergy use for greenhouses heatingMacedonia doesn't have organized stateapproach to this economy sector. Theperspective in Macedo-nian geothermalfields depends of foreign in-vestment. Thereis action in Katlanovo spa to introducegeothermal heating in the buildings andmodernization of the spa capacities. TheWorld Bank pre-feasibility study resultedwith positive economical justification of theneces-sary investments. Few years agothere were investments from AustrianGovernment applied in geothermal fieldIstibanja and Podlog.

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Table 1. State-of-the-art of the geothermal energy use in Macedonia

GEOTHERMALLOCATION

GEOTHERMALFIELD

APPLICATION HEAT POWERTOTAL GEOTHERMKW KW

HEATINGINSTALLATION

Istibanja Greenhouse heating(6.0 ha)

17.500 2.350 Aerial steel pipesKochanivalley

Podlog Greenhouse heating(12.0 ha)Rice drying,Paper industry,Space heating

40.700

1.6003.200650

20.500

1.6003.200650

Aerial steel pipesSquare finned pipersheat exchanger(water/air)Plate heat exchangerAl and Fe radiators

Strumicavalley

BanskoGreenhouse heating(2.9 ha)Greenhouse heating(600sq.m)Plastichousesheating (3.0 ha)Space heatingSanitary warm waterpreparationSwimming poolheatingBalneology

9.000

150

3.000

1.560700

350

9.000

150

3.000

1.560700

350

Aerial steel pipes andsurface steel pipesCorrugated PP pipeson surface+fan jet airheatingSoil heating

Al radiatorsPlate heat exchanger+warm wateraccumulatorPlate heat exchanger

Smokvica Greenhouse heating(22.5 ha)Plastichousesheating (10.0 ha)

65.500

10.000

11.750

10.000

Aerial steel pipes +corrugated PP pipeson surfaceCorrugated PP pipeson surface

Gevgeliavalley

Negorcispa

Space heatingBalneology

250 250 Steel radiators

Volkovo Gasses exploitat.Bottling

Skopjevalley

Katlanovospa Balneology

Kumanovo Proevcispa

Bottling

Stip Kezovicaspa

Balneology

Debarskaspa

BalneologyDebar

Kosovrastispa

Balneology

Strnovec no useKratovo-Zletovo Povisica bottling

Topli dol bottlingMrezicko bottling

Kozufmountain

Toplik no useTOTAL 62,46 ha greenhouses 82.560 kw

Space heating (5 units)Paper industry (1 complete)

Sanitary warm water preparation (2 units)Rice drying (1 unit)

Swimming pool heating (1 unit)Balneology ( 8 spas)

Bottling mineral water (5 projects)Gases exploitation (1 unit)

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REFERENCES

Arsovski M. (1997). Tektonika naMakedonija,Stip,306pp

Bilibajkic P and all. (1963). Geofizicka ispitivanjaSkopske kotline-gravimetrija. Report Zavodza geoloska i geofizicka istrazivanja,Beograd. 80pp

Fridleifsson I.B (1986) Geothermal resources;present status and future potential in theworld energy supply, 13 Congress of theWorld Energy Conference, Cannes, France

Gorgieva M. (1989). Chemical geothermometers

and mineral equilibria of some hot waters inYugoslavia. Report UNU GeothermalTraining Programme, Reykjavik, 61pp

Gorgieva M. (1998) Summary of fundamentalsfor evaluation of the geothermal potential ofthe Vardar zone and Serbo-Macedonianmass in the territory of the Republic ofMacedonia, Macedoni-an/U.S.A scientificproject: Evaluation of reserves and tecnicalfeasibility of geothermal energy inMacedonia, Skopje. pp 63-110

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GREENHOUSE COMPLEX COMPLEX OF SMALL SOFTPLASTICS COVEREDGREENHOUSES

SANITARY WARMWATER FOR OTHER HOTELS

HOTELCAR SAMUIL

COMPLEX OF SMALL SOFTPLASTICS COVEREDGREENHOUSES

Centralheating

Tap warm water

Peak-up boiler

Swimming pool

PUMP STATION55 l/s70ºC

25 l/s 5 l/s 25 l/s

35-40ºC

25-30ºC

35ºC 15ºC

70ºC

70ºC

70ºC

70ºC

50ºC

50ºC

35-50ºC50-70ºC

35-50ºC

35-50ºC

25-28ºC

65ºC

45ºC

90ºC70ºC

15ºC

45ºC

Fig.4. Scheme of the geothermal system Bansko (Popovski, 2002)