Extension of Transmission Network Project
Environmental and Social Impact Assessment for Construction
of 500 “KSANI-STEPANTSMINDA” TRANSMISSION LINE
DRAFT TECHNICAL SUMMARY
Prepared by: Foundation World Experience for Georgia
March
2015
Tbilisi
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TITLE
PAGE
Project Title:
Extension of Transmission Network Project
Document Title:
Nontechnical Summary of Environmental and Social Impact
Assessment for Construction of 500 “KSANISTEPANTSMINDA” TRANSMISSION LINE
Prepared by:
Foundation World Experience for Georgia
Date Prepared:
March
Principle Authors
Medgar Chelidze; Irakli Kaviladze; Andrei Kandaurov;
Mariam Kimieridze;
WEG Project Manager
Medgar Chelidze;
Project Oversight
Client's Side:
2015
from
EnergoTrans
Mrs. Maya Gikoshvili
Deputy Director, EnergoTrans Ltd.
GSE
Mrs. Maya Pitskhelauri
Reporting & International Project Coordination
Department Manager
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ABBREVIATIONS
EBRD
European Bank for Reconstruction and Development
ESIA
Environmental and Social Impact Assessment
ESAP
Environmental
UNECE
United Nations Economic Commission for Europe
EU
European Union
GSE
JSC
GoG
Government
MoE
Ministry of Environmental Protection
NGO
Non-Governmental Organisation
SEP
Stakeholder Engagement Plan
and
“Georgian
Social
State
of
Action
Plan
Electrosystem”
Georgia
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TABLE OF CONTENTS
1.
Background Information
4
2.
Project Description
6
2.1
Overall Context
6
2.2
Current Project
6
2.3
Conductor selection
7
2.4
500 kV tower types
8
2.5
Substation Location in Georgia
9
2.6
OHL Basic Design
10
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1. Background Information
Georgian State Electrosystem JSC (hereinafter referred to as “the Client” or “GSE”), a 100%
state-run company providing transmission and dispatch services throughout the territory of
Georgia intends to construct the 500kV “Ksani-Stepantsminda” Transmission Line that will
serve the purpose of evacuation of power from the Dariali and Larsi HPPs being under
construction in Dariali ravine, Mtskheta-Mtianeti region as well as from other perspective
HPPs planned to be constructed in the area and connect such HPPs to the national grid.
The construction of a new 500kV “Ksani-Stepantsminda” power transmission line will:



ensure the connection of HPPs being under construction to the power grid;
contribute to the role of Georgia as of energy transit corridor in the North-South
direction;
improve the uninterrupted and reliable power supply to Mtskheta-Mtianeti region,
meeting the increasing demand of the region as a developing recreation and resort
area.
500kV “Ksani-Stepantsminda” Transmission Line (approximately 95km) will initially operate
under 110kV voltage and handle the surplus hydropower and ensure safe, efficient and highquality power supply operations. The line will be connected to110 kV S/S Kazbegi with the
extension of 110kV Dariali power transmission line. The corridor of the line is KsaniVedzatkhevi-Qartali highway crossing near Fasanauri-Tsinamkhari-Kitokhi-Gudamakari
Pass-Karkucha-Sno-Achkhoti. Pursuant to the geographic location of the region this corridor
is deemed to be of moderate complexity for the construction of 500kV power transmission
line. No sharp elevations variances of heights throughout the whole route is met.
An alternative arrangement near Ksani S/S is proposed in order to avoid the double crossing
of the 110 kV (green) and Kartli lines (yellow). It foresees a bay rearrangement by locating
the Kazbegi line (blue) between the existing 500 kV incomers (Figure 1).
The Client has approached the European Bank for Reconstruction and Development (EBRD)
and Kreditanstalt fuer Wiederaufbau (KfW) for financing of this new project (hereinafter “the
Project”).
In compliance with the EBRD, KfW and Georgian legislative requirements, it is necessary to
prepare environmental and social Impact assessment of the Project, and the Client seeks
consultant service in elaboration of this document.
The Project is designed to meet all relevant Georgian requirements, the KfW's and EBRD’s
Environmental and Social Policy (ESP) of 2008’s and associated Performance Requirements
as well as best international practice. Performance Requirement 10 requires a Stakeholder1
Engagement Plan (also known as a public consultation and disclosure plan -- PCDP) should
be developed and implemented by the project proponents.
This Project is qualified as Category A under the EBRD's 2008 Environmental and Social
Policy (Policy). Thus, an environmental and social impact assessment (ESIA) is required.
The project proponents are: Georgian State Electrosystem JSC (“GSE”) and Energotrans
Ltd., The developer of the Project, “GSE” is a 100% state-run company providing
transmission and dispatch services throughout the territory of Georgia. Energotrans Ltd., a
fully owned subsidiary of GSE.
1
“Stakeholder” is a person, group or organization that is affected or can be affected by the environmental and/or social
consequences of a proposed project/activity; this includes individuals/groups/organizations that express interest in the
project/activity and in the participation to round tables and discussion meetings, and/or are able to influence the project’s
implementation and/or operations.
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JSC GSE has engaged Foundation World Experience for Georgia (WEG) for developing
Environmental and Social Impact Assessment related to the Project. The current document,
which has been developed by WEG at the early stage of ESIA process, describes the
general features of the existing natural and social environment and outlines major
environmental in relation with the Project.
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2. Project Description
2.1 Overall Context
Stage 1: Construction of the 500 kV OHL between the Ksani 500/220/110 kV S/S and a
new Stepantsminda 110 kV S/S
Operated initially at 110 kV, the OHL will serve mainly for connection of the regional HPPs
capacity now under development to the GSE transmission system evolving from Ksani. The line
length according to the preliminary route survey is 100km.
Stage 2: Construction of the 500 kV OHL between the new Stepantsminda 500kV S/S and
Mozdok 500kV S/S
Based on the available regional development data for demand and generation, the targeted
transmission capacity shall be minimum 400 MW for the operation at 110 kV and 1100 MW for
the operation at 500 kV.
The Ksani-Stepantsminda-Mozdok 500 kV OHL represents an essential element for the
economic use of the cross-border interconnection capacities already under construction,
especially those with Turkey and Armenia which might require for full utilization a significant
share from UPS should there be constraints on generation in Georgia. At the same time, the
Project enhances the security of the GSE system supply by better integration of the 500 kV
transmission network into the regional grid with the resulting increased immunity against internal
outages.
2.2 Current Project
The present Scoping Report and related ESIA are focused on the first stage sub-project:
Construction of the 500 kV OHL between the Ksani 500/220/110 kV S/S and a new
Stepantsminda 110 kV S/S.
The Stepantsminda substation is located on a flat hill top about 1750 m above sea level, close
to Stepantsminda town. The Ksani substation area is located on a flat hill top about 550 m
above sea level near the town of Ksani.
The proposed 500 kV transmission line starts from the Ksani SIS near Tbilisi and goes North up
to the future Stepantsminda SIS. With a length about 100km, the 500 kV line will reach an
altitude of about 2500m.
An alternative arrangement near Ksani SIS is proposed in order to avoid the double
crossing of the 110 kV (green) and Kartli lines (yellow). It foresees a bay rearrangement by
locating the Kazbegi line (blue) between the existing 500 kV incomers.
OHL construction can be rated as difficult for approximately 30% of the line length, due to the
high altitude and narrow corridors in the Kazbegi mountainous area. For approximately 10% of
the line length, the study recommended using catenary suspension instead of towers, for both
new SOOkV and existing 110 kV OHLs. Since this corridor is exposed to avalanches, floods
and landslides, this solution lowers the risks of construction and operation of the Iine and has
already been successfully used around the world in construction areas of similar difficulty,
among others for the Kavkazonia SOOkV OHL.
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Fig. 1 MAP of the Project Transmission Line
2.3 Conductor selection
Considering the above design figures and Consultant's experience with the 500 kV Gardabani Akhaltzikbe line, it is proposed to adopt for the OHL 500kY Stepantsminda Dariali- Larsi Russian the following conductor types:
- AC-400/93 mm2 in sections up to altitudes of 2000 m
- AC-300/204 mm2 in sections above 2000 m
Considering the required line transfer capacities, the line shall be equipped in Sections I, 2,
3 and 5 with triple bundle ACSR type AC-400/93 conductor suitable for 500 kY nominal voltage.
In Section 4 and in all other sections where the spans exceed 800 m, the line shall
be equipped with triple bundle AC-300/204 conductors.
Depending on the Stage of the Project, the rated design capacity of the Kazbegi line under
consideration of a minimum power factor of 0.95 and a Transmission Reliability Margin will be
254 MW in Stage 1 and 1155 MW in Stage 2 under reference conditions. These capacities are
in line with the defined trading scenarios in Chapter 3 and the power system analysis
investigation.
The standard towers are designed to withstand the loads of two ground wires, i.e. one C7070 mm2 standard galvanized and one OPGW-70 mm2
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In Section 4 and for spans over 800 m the ground wires shall be of C-95 mm2 or C-120 mm2
standard galvanized types, respectively OPGW-95 mm2 or OPGW-120 mm2 types. According
to local construction experience, the ground wires are insulated by two insulators and partly
connected to earth wire peaks to minimize the induced currents and ultimately the losses.
Because this approach is not possible for OPGW's, both ground wires shall be installed using
tower-bonded sets.
2.4 500 kV tower types
Recommended tower types for single circuit sections
The tower types for the Kazbegi line (Georgian section) could be the standardized towers
already in use for 500 kV GSE OHLs. However, for the Ksani - Stepantsminda 500 kV
OHL it is proposed to adopt a Riumka shaped tower types (see fig. below) in accordance with
the European design practice for technical reasons detailed below. It is mentioned that the
Riumka geometry was the preferred choice also for the Georgia Turkey 400kV OHL
interconnection and for the Kavkasioni 500 kV line between Murjava and Jvari 220 kV
substation.
Since tower weights are not very different from the corresponding existing structures, the
benefits of the proposed type shape are:
- easy transportation and erection
- easy civil works for foundations, due to the "in situ" casting which avoids higher
stresses at the tower-foundation interfaces caused by manufacturing tolerances
and the difficult transport of pre-casted foundations
- economic design using Body Extensions and Leg Extensions to obtain towers
heights from -6 . .. +15m, with one meter increment.
To fulfill the design conditions it is proposed to adopt the tower families listed below.
Normal structures, to be used in Sections I, 2, 3 and 5, featuring:
- Wind pressure
100 daN/mm2
Ice depots
20 mm thickness
- Suspension structure
- Angle-tension structure for low line angles
0° ... 30°
- Angle-tension structure for medium line angles
30° ... 60°
- Angle-tension structure for high line angles
60° ... 90° and Dead End
Special structures, to be used in Section 4 and in line sections with spans longer than
800m of Sections I , 2, 3 and 5, featuring:
- Wind pressure
156 daN/mm2
- Ice depots
40 mm thickness
Heavy suspension structure
- Heavy angle-tension structure for line angles
30° ... 60°
The towers shall be equipped with composite insulator types, easy to be transported and
maintained in mountain areas.
Combined 500kV & 110 kV towers
For the Stepantsminda to the Russian border, in case that the existing line route will be
relocated, it is proposed to adopt a Hexagon shaped tower family. The towers shall be equipped
on one side with a 500 kV circuit and on the other side with the relocated 110 kV line circuit.
Catenaries for shared 500kV & 110 kV OHL sections
In areas with avalanches or with big crevasses the catenary suspension shall be adopted, as
exemplified in Figure.3. Catenaries were already applied for the Kavkasionia 500 kY
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line with very good results. Positive experience with this type of suspension is also available
from other countries, as detailed in the Inception Report of for this project.
Fig.2. Riumka tower type for the Kavkasioni 500 kV line
Fig.3 Catenaries suspension for the Kavkasionia 500 kV line
2.5 Substation Location in Georgia
The project region is located in the middle and northern part of Georgia near to Tbilisi (30km
West ofTbilisi) and the border to Russian border close to Kazbegi mountains.
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Approximate road distances are:
- Tbilisi - Ksani :::: 30 km
- Tbilisi - Stepantsminda :::: 130 km
- Stepantsminda - Russian Border :::: 15 km
With the exception ofa short distance in Ksani and Stepantsminda, the road connections are
suitable for transport of heavy goods.
Stepantsminda substation area is located on a flat hill top at about 1000 m above sea level,
close to the Stepantsminda town . The Ksani substation area is located on a flat hill top at about
300m a.s .l. near the Ksani town.
Stepantsminda Substation
Two options for the connection of the transmission line from Ksani to Stepantsminda and
interconnection with Dariali Hydro Power Plant SIS are under review:
- Connection of the line at the Kazbegi 110 kV substation owned by Energopro, which
needs engineering and coordination for substation rearrangements and equipment
upgrades (GSE proposal)
Insertion of the new Stepantsminda 110 kV SIS in the Gadauri line as recommended by
Fichtner in Feasibility Study.
The construction stages of the Stepantsminda SIS depend of course of the adopted solution
for the temporary 110 kV operation of the Ksani OHL and if a fully fledged 110 kV
Stepantsminda busbar will be required.
Ksani Substation
For connecting the OHL Stepantsminda a rearrangement of 500 kV bays was proposed(refer to
chapter 2). The Ksani SIS works shall be carried out in two stages, coordinated with the ongoing rehabilitation of the substation.
Stage 1
Installation of overspan from 500kY OHL Stepantsminda gantry to the A T4 transformer
gantry
Installation of bypass from 500kY switchyard to 110 kY switchyard (four existing towers
can be used and five new towers shall be installed)
Installation of a gantry in the II OkY switchyard for incoming bypass
- •Installation of one llOkY switching bay
Stage 2
Removal of overspan from 500kY OHL Stepantsminda gantry to AT4 transformer gantry
- Removal of bypass from 500kY switchyard to II OkY switchyard
Installation of one (1) 500k Y switching bay
- Connection ofOHL Stepantsminda to the 500kY switchyard
2.6 OHL Basic Design
In terms of transfer capacity, the Feasibility Study proposed different 500kV conductor types
suitable to line sections with normal or special construction difficulty levels, enabling a
throughput of minimum of 1100 MW under rated site condition. This design capacity was
validated by the power system analysis considering the vertical peak load of the GSE system
within the planning horizon onto the regional trade scenarios, making full use of the crossborder HYDC BtB transfer capacity in operation or committed.
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Considering the construction and access difficulties, the study proposed to use single structure
European types of towers due to:
 easy transportation and erection
 "in situ" foundation casting which avoids higher stresses of the steel tower structure
caused by manufacturing tolerances or transport of pre-casted foundations
 economic design using body and leg extensions
The extension of the Ksani 500 kV and 110kV switchgears is not a critical issue but requires a
careful coordination with on-going substation rehabilitation, especially if the study proposal to
rearrange the 500 kV bay sequence in order to minimize outgoing OHL line crossings is
adopted. There are no technical or time schedule difficulties foreseeable for construction of the
new Stepantsminda S/S which is located in a flat area with good access roads and can make
use of the well proven GSE standard transmission substation design.
Implementation Schedule
The scheduled completion of the Georgian section of the line up to Stepantsminda S/S is by the
end of 2016, coincident with commissioning of the new Dariali HPP. While being ambitious, the
line construction schedule is technically feasible assuming parallel working of line construction
teams, quick construction route approval and work permitting procedures and upgrade of
access roads in the mountainous sections as far as possible in the pre-construction phase.
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