Presentation on theme: "Interconnection of the Cycladic islands of Syros, Tinos, Mykonos, Paros and Naxos to the Mainland System via submarine cables A. Koronides, S. Efstathiou."— Presentation transcript:
1 Interconnection of the Cycladic islands of Syros, Tinos, Mykonos, Paros and Naxos to the Mainland System via submarine cablesA. Koronides, S. Efstathiou G. Koutzoukos, N. Boulaxis
2 BackgroundThe Interconnection of the Northern Cycladic Islands has been considered as early as the early 90‘s because of:Rapid growth of their consumption (development due to tourism)Building new Generating Capacity was always very difficult due to environmental constraints (all existing in proximity to the main towns)High operating cost using diesel and heavy fuel
4 Evolution of Demand Evolution of Energy demand (1980-2004) 2005Evolution of Peak load ( )Year of connection of Andros-Tinos to the Mainland
5 Load Forecast Forecasted Energy demand (2005-2025) Forecasted Peaks ( )
6 Possible additional capacity Local Generation[MW]1020304050607080901520 (30)116854342412.3AndrosSyrosMykonosParosCurrent capacityPlanned ExpansionPossible additional capacity
7 Initial Interconnection Plan Introduced in the late 80’s to be implemented in early 90’s :weak interconnection to the Mainland by single cableOHL on the islands and submarine cables between them (shortest distances)development of new geothermal power plant in MilosForeseen implementation in two phases:Phase A: interconnection of Andros,Tinos, Mykonos and Syros to the MainlandPhase B: expansion of the connection to Milos (reaching the Geothermal Field) and installation of Geothermal Power Plant in Milos
9 What has been done (1/2) By the end of the 90´ were installed the cables (mid 90’s ) :Main System – AndrosAndros – TinosTinos – SyrosTinos – Mykonosthe OHL over Andros (late 90’s)
10 What has been done (2/2) In the meantime : Local Reaction against construction of OHL (150kV, 66kV) on the islands has escalatedalsoLocal Reaction against Geothermal plant in Milos startedHowever, a new interconnection plan was prepared
12 Revision of Initial Plan (2001) Expansion of the Interconnection to Paros and NaxosRevised plan for installation of new “big scale” thermal station in NaxosExpectations to overcome local reactionsSitting of thermal station in Naxos considered possible
13 Court Decisions (2001-2004) Local Reactions Escalated State Council Decision was issued against construction of new High Voltage Lines on the IslandsSitting of new thermal stations almost impossibleNevertheless in 2003 the construction of an AIS in Andros was completed
14 New Design ( )Facing said facts, a more “pragmatic” design was doneNo new OHL over the islandsNo new thermal stations on the islandsUse of existing thermal plants only as cold reserve - No thermal Production on the islandsPossibility to exploit significant wind capacity (installation of W/F)
15 Final Plan (2005) Existing 150kV OHL New 150kV OHL Existing 150kV submarine cableNew 150kV submarine cableExisting 66kV cableExisting 150kV substationNew 150kV substationExisting PS
16 Pros and Cons of the Interconnection Secure power supply of the Islands (from the mainland interconnected grid)Long-term solution – no new local generation every 2-3 yearsSubstitution of power (Diesel) from existing local PS (gradual decommissioning) with power from the Interconnected System Economic and Environmental benefitsIncrease of wind power penetration on the interconnected islandsPossible future extension of the Interconnection to the Southern Cycladic Island (further exploitation of considerable wind and geothermal potential of the islands)More economical than feeding the islands by diesel stations in the long runConsConsiderable initial investment cost:submarine cablesadvanced interconnection technology (DC with VSC, GIS substations,)Long amortization periodUse of new innovative, but not sufficiently proven technologies (long XLPE* submarine cables, DC control in abnormal situations e.t.c).* XLPE cables have low MVAR/km than OIC (1,5 vs 2,5)
17 Technical Description 4 new GIS Substations 150/20kV in Syros, Mykonos, Paros and NaxosSubmarine Interconnection of above substations (cables 1×3phase / AC / XLPE / 150kV / 200MVΑ):Syros - Mykonos 36kmSyros - Paros 50kmParos - Naxos 16kmNaxos - Mykonos 40kmSyros - Andros 32kmReactive compensation (reactors) of the cables is requiredSubmarine Interconnection of Syros to the Mainland (Lavrion EHV Substation). Two alternative technologies:D.C. Interconnection:Submarine D.C. interconnection Lavrion - Syros ~100km 250ΜW (2+1 cables)An AC/DC converter station at each end of the interconnection (-50/+150ΜVA)A.C. Interconnection:Submarine A.C. interconnection Lavrion - Syros ~110km 250ΜW (2×3phase / AC / XLPE / 150kV / 200MVΑ).One stop at Kythnos for junction and reactive compensation with SVC in Syros ~ +/- 150 MVAR
18 Basic Economic and Technical assumptions Basic economic assumptions (in 2005 prices)Inflation3%Rate of fuel price variation above Inflation2%Cost of FuelDiesel410 €/t*Heavy oil190 €/tCost of Energy from Interconnected System54 €/MWhCost of Energy from local PS80 €/ΜWhO&M cost of old local PS96.03 €/KW&yearO&M cost of expansion of existing local PS38.41 €/KW&yearInvestment Cost (after taxes)7%-9%Basic technical assumptions (in 2004 prices)CO2 emissions8-20 €/ton CO2Efficiency of new PS (diesel)42%Investment Cost (new PS)1100 €/KW&yearCost of Expansion of old PS825 €/KW&yearΠηγή: ΔΕΗ/ΔΣΠ* Price in €/lt
19 Comparative Cost Analysis (estimates with 2005 prices in MEuros) Cost Component [MW]Final SolutionExpansion of existing PSNo further interconnectionLeast Cost Approach*Investment Cost170 ~230133.03101.26Cost of Fuel (Diesel)**472.74Cost of Energy from Interconnected System38061.62380.72CO2 emissions 011.86Fixed O&M Costs10 ~ 7549.5348.62Total Cost728.77*530.6* new OHL over the islands, submarine cables between the islands, connection with new cables and lines to the north** New prices increase 40%new oil prices
21 A.C. Solution Lavrion EHV 400kV ~ Transformer 400/150kVANDROS150kV150kV~1×9MVAr1×18MVAr1×18MVAr1×16MVArMYKONOS150kV150kV XLPE AC2×3ph/280MVA110km150kV XLPE AC1×3 200MVA32kmJunction point in the island of Kythnos1×18MVAr1×9MVAr2×18MVAr(junction at Kythnos)1×16MVAr1×16MVAr150kV XLPE AC1×3 200MVA36km1×18MVAr150kV XLPE AC1×3 200MVA40km1×18MVAr1×18MVAr1×16MVAr~1×18MVAr1×18MVAr1×16MVAr1×9MVAr150kV XLPE AC1×3 200MVA50km150kV XLPE AC1×3 200MVA16kmSVC-50/+150MVAr1×9MVArSYROS150kV1×16MVAr1×9MVAr1×9MVArPAROS150kV1×16MVAr~
22 Conclusions 1/5Expansion of the Network (Overhead Lines) Faces huge local ReactionGeneralized use of Cables is not realistic:Huge CostTechnical Problems (reactive capacitance)Use of Cables in the mainland is restricted to very specific cases involving heavily populated areas
23 Conclusions 2/5The Cycladic Islands are the closest islands of the Aegean Archipelago to the mainland.They represent a significant load with high rate of increase.Development of local generating units is associated with high operational cost and practical difficulties to find new locations.A submarine “cable” connection to the mainland is the only “pragmatic” solution.
24 Conclusions 3/5The least cost solution, would involve several overhead HV lines on islands and new ~70km in the mainland in EviaNew OHL on the Islands would “insult” dramatically the aesthetically sensitive landscape of the islands and was denied by the State CouncilLicensing of new long OHL in Evia considered impossible
25 Conclusions 4/5 Solution Chosen : Long Submarine Connection of the central island of Syros to the Lavrio production center in the mainland and,DC converters and cables orAC XLPE Cables and junction in island in about half distance plus SVC in SyrosConnection to other Islands by AC XLPE cables
26 Conclusions 5/5 Solution Chosen Has high initial investment cost But is economically feasible in the long runIs environmentally friendly, therefore is pragmaticAllows installation of Wind Power up to about the peak load of the islands (otherwise very limited)Is acceptable by the local communities
27 Other interesting cases experienced by HTSO (1/4) CorfuSouth Evia
28 Other interesting cases experienced by HTSO (2/4) In the Island of Corfu a second 150 kV submarine cable was planned to satisfy the reliability needs for the island (N-1 criterion )Total length ~ 17 km submarineTo ease the local reaction the 3 km OHL line on the island was designed as underground cableNevertheless the project faces big delays since reaction appeared requesting transferring of the local Substation (existing for many decades) to a new location and use of GIS technology.
29 Other interesting cases experienced by HTSO (3/4) A new Connection of Evia to the mainland was designed to support Wind EnergyInitially least distance submarine cable solution was chosen (~17 km OHL and ~8 km submarine cable)It was rejected and replaced by a solution with~ 20 km submarine cable and 2 km underground cable through a small townRecently, local reaction appeared against the underground cable through the town.
30 Other interesting cases experienced by HTSO (4/4) Lesson Learned :Use of cables,Although is expected to be acceptable by the local societiesmight bring new reaction andfurther requests.