Transcript Unbundling of NEA - PTC India Limited

STATUS OF TRANSMISSION LINE
AND EXPANSION PLAN IN NEPAL
S. Rajbhandari
Components of Power System
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Electrical power system mainly consist of three
systems or components:
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Generating system
Transmission system
Distribution system
Generating system consists of generating stations
or power houses where stored in various forms
(examples: water at height, heat energy in coal or
oil or nuclear energy in the atoms of fissionable
fuels) are converted into electrical energy.
Components of Power System contd.
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Transmission system transmits electrical
energy in bulk, generally from generating
stations to the primary substations.
Distribution system is the system from
which electrical energy is distributed to
various consumers such as domestic,
commercial, industrial, non commercial etc.
NEA Transmission System
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Grid (INPS) extends from east to west, ie.,
Anarmani- Mahendranagar
Major hydro stations connected to the grid.
GSS Capacity: 1310 MVA
132 kV line length: 2076 cct Km
66 kV line length: 586 cct Km
NEA Transmission System contd.
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Principal voltage of grid system is 132 kV.
Majority of the lines constructed with
double circuit, except for Bardghat-Hetauda
section
Constructed with conductor BEAR and
DUCK except for Bardghat-Hetauda and
Bharatpur-Pokhara
Single Line Diagram of INPS
Single Line diagram, INPS
I
Modi
Trishuli
MMRS
Lamosangu
KGA
Jhim
M/ nagar
Dubi Anarmani
Lamai
Butwal
Tanakpur
Bhrtpr
Htd
Chapur Dhalke Lahan
Parwanipur
Birgunj
India
Integrated Nepal Power System
(INPS) Map
(NOT TO SCALE)
Why Transmission System Expansion ?
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To provide greater reliability and capacity
To increase the ability to distribute
available power to meet existing and future
demands
To meet NEA’s contractual obligation for
transmission with various power producers
To increase NEA’s ability to import/export
power
Transmission Development
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Before 1985:
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No systematic planning carried out.
Transmission expansion mainly by ED, tandem of new
HEP.
Major transmission Projects (about 800 km)
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Trishuli – Balaju – Hetauda – Birgunj
Sunkoshi – Patan
Gandak – Bharatpur – Hetauda
Devighat – Chabel
Bardghat – Butwal - Kohalpur
Hetauda – Dhalkebar
Bharatpur – Pokhara
Suichatar – KL2 - Hetauda
Transmission Development contd.
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Period Between 1985 - 1992
Transmission network planning started in 80s.
NEA Act implemented for effective monopoly
NEA Prepared and updated its corporate plan
Long term demand forecasting
LCGEP
TSMP
Distr. Plan
Transmission Development, 85-92
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NEA LCGEP, TSMP & DEP treated as
national plans.
NEA responsible for phased
implementation Grid interconnection
domestic or interdepartmental affair.
Major Transmission Projects during the period
(approx.500km) :
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Dhalkebar – Duhabi – Anarmani
Kohalpur – Mahendranagar
Balaju – Marshyangdi - Bharatpur
Transmission Development after 1992
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Period after 1992:
New Electricity Act; Hydropower Development
Policy
IPPs have access to generation;
NEA the grid owner and IPPs the grid user for
existing grid.
Absence of national Grid code led many issues
related to grid planning, expansion, operation,
interconnection to remain as grey areas.
Grid Interconnection no more interdepartmental
issue
Transmission Development after 1992
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NEA faced four problems:
 What level of generation development to be
considered/planned for transmission expansion?
IPPs have license throughout country.
 Which expansion to be given priority?
 What performance standards to be adopted for
expansion planning?
 Source of funding. Where does the money will
come from for transmission expansion?
Mismatched Triangle
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NEA, IPPs and Government bodies
NEA
Government bodies
MOWR
WECS
DOED
Roles and
Responsibilities as per
NEA Act
IPPs
Roles / responsibilities
As per Electricity Act
Monopoly operation
Forced to single buyer
Missing
Roles
Responsibilities
Functionalities
Structures
Single buyer market
Transmission Development after 1992
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IPPs are awarded license wherever they apply for and
wish to develop power projects where they have
license for.
IPPs expect NEA to provide evacuation/
interconnection where they want.
Their proposals for power evacuation include:
 either to break the existing trunk lines for
interconnection
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or new transmission line to be constructed by
NEA.
Transmission Development after 1992
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NEA refuses:
 interconnection that harm grid security
 to add transmission capacity due to lack of
funds.
Rigid stands taken by both NEA & IPPs helped to
create bottlenecks or congestion.
Ultimately very little transmission expansion
realized. Such expansions include (approx. 345
km):
Transmission Development after 1992
Khimti – Lamosangu – Bhaktapur ( NEA)
 Lekhnath – Kaligandaki – Butwal (NEA)
 Chilime – Trisuli (NEA)
 Pathlaiya – Parwanipur (NEA)
 Bhotekoshi – Lamosangu (Private)
 Indrawati – Paanchkhal (Private)
 Jhimruk – Lamahi (Private)
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Current Situation
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The conflicting interests created
transmission bottlenecks.
Transmission congestion in many sections
of the INPS.
NEA transmission plan focuses on meeting
its internal demand and limited export.
The TSMP envisages a 220 kV backbone
for the purpose.
INPS
Western Area
KGA
Modi
MMRS
Pokh
Lekh
MRS
Jhim
Damau
M/ nagar
Lamai
Tanakpur
Butwal
Bard
Kawasoti
Htd
Bhrtpr
INPS
Central and East
Trishuli
Lamosangu
MRS
Dubi Anarmani
Htd
Bharatpur
Chapur Dhalke Lahan
Parwanipur
Birgunj
India
Transmission Line Reinforcement Plan
S. No.
Transmission lines
Proposed year
Status
1
Birgunj Corridor 132 kV
2006/07
abandoned
2
Butwal Sunauli 132 kV
2007/08
abandoned
2007/08
Under const.
2007/08
Under const.
2007/08
Planned
Thankot-Chapagaon-Bhaktapur 132 kV
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4
5
Khimti Dhalkebar 220 kV
Kohalpur-Lamahi-Shivpur-Butwal and Khimti
Dhalkebar second circuit stringing
6
Hetauda-Bardghat 220 kV
2009/10
Under const. (HetBharatpur)
7
Bardghat-Butwal 220 kV
2011/12
Planned
8
Hetauda-Thankot 220 kV
2011/12
Planned
2011/12
Planned
Bharatpur-Hetauda 220 kV second circuit stringing
9
Transmission Lines Planned/Proposed
for Power Evacuation
S. No.
Transmission lines
Proposed year
Status
1
MiddleMarsyangdi-Marsyangdi 132 kV
2006/07
Completed
2
Kul III-Hetauda 132 kV
2008/09
abandoned
3
Upper Modi-Modi Khola 132 kV
2009/10
Planned
4
Madi I-Lekhnath 132 kV
2009/10
Planned
5
Chamelia-Ataria 132 kV
2010/11
Planned
6
Mewa -Tamor 132 kV
2010/11
Planned
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Hewa-Kabeli 132 kV
2010/11
Planned
8
Lower Modi-Modi 132 kV
2010/11
Planned
9
Sanjen-Chilime 132 kV
2010/11
Planned
Upper Mars-Middle Mars 132 kV
2011/12
Planned
10
Transmission Lines Planned/Proposed
for Power Evacuation contd.
S. No.
Transmission lines
Proposed year
Status
11
Kabeli-Duhabi 132 kV
2011/12
Planned
12
Upper Tamakosi-Khimti 220 kV
2012/13
Planned
13
Tamor-Kabeli 132 kV
2013/14
Planned
14
Kankai-Duhabi 132 kV
2013/14
Planned
15
Upper Karnali-Kohalpur 132 kV
2013/14
Planned
16
Upper Seti-Bharatpur 220 kV
2013/14
Planned
17
West Seti-Ataria 132 kV
2014/15
Planned
18
Likhu-Khimti 132 kV
2017/18
Planned
19
Rahughat-Pokhara 132 kV
2017/18
Planned
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Dudh Kosi-Dhalkebar 220 kV
2018/19
Planned
21
Andhi khola-Butwal 132 kV
2020/21
Planned
22
Lamosanghu-Singati 132 kV T/L
Planned
Planning Dilemma
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For what capacity to plan the transmission
network? Who can expand transmission when
nobody knows what is required? For 83000 MW /
42000 MW? Or for 3200 MW for 2025/26?
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Planning horizon?
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Operational planning of one year.
Medium term 1 to 5 years
Long term more than 5 years
Where does the money come from if NEA is to
satisfy IPPs’ demand?
Over investment: low network utilization
Planning Dilemma contd.
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Under investment: limit the use of renewable,
increase congestion
A transmission system should have ample margin
to allow for contingencies and should deal with
the uncertainties of long range forecasts.
A properly designed transmission system provides
a good distribution of power flows by avoiding
excessive geographic concentrations of generating
sources or transmission paths.
Planning Dilemma contd.
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Performance standards provide the basis for
determining whether system response to the
contingency tests is acceptable. What limits/
values to be adopted for these performance
standards: thermal, voltage, relay, stability and
short circuit.
The maintenance is another issue. An economic
network or maintain economy in the life cycle.
What contingency levels to be followed? N-1, N-2
or N-3?
Planning Dilemma contd.
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Multiple contingency events include the loss of:
A tower-line with three or more circuits
All transmission lines on a common right-of-way
Any transmission station including associated
generation
All generating units at a power plant
A transmission line or transformer when another
transmission line or transformer is out
of service
Development Options and Issues
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Generation and Transmission expansion case of chicken
or egg story.
For unhindered development of transmission network,
Develop networks on the basis of investment, ownership
and purpose :
 INPS owned by Central Transmission Utility (CTU)
 Commercial or merchant lines of private companies
 Cross border lines connected to INPS
 Dedicated cross border lines
Development Options and Issues
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Issue is who will, when and how plan
expansion, approve, implement and own it
and operate transmission systems
concerning above models.
Investment for speedy growth is another
issue.
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Government should invest in transmission.
Economic feasibility instead of financial feasibility
Development Options and Issues
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Shall we have a Central Transmission Utility (CTU)?
If we have a CTU then shall we have more than one
domestic transmission operators?
How shall we attract private investment in transmission?
How to fix wheeling charges: MW Miles, capacity
booked or postage stamp
Shall we issue transmission licenses anywhere,
everywhere like generation licenses?
Development Options and Issues
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For what capacity shall we develop our network :
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Shall we have separate domestic and export networks?
Or allow domestic network for sole export plants?
What will be interface of domestic and export network,
AC Synchronous or HVDC back to back?
How shall we export internal surplus through domestic
network?
 NEA as net integrator and nodal agency?
 Generators themselves? (Use of CTU network)
 Trading companies (Use of CTU network)
Transmission System for Future
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Plan for a long horizon.
North South River basin plans:
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Kosi Basin
Gandak basin
Karnali-Mahakali Basin
Southern East West Trunk Line
Mid Hill East West Trunk Line
Export System
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Overall INPS Scheme
Trishuli
(Courtesy: S.S. Bhat)
Modi
Lamki
Damauli
Kathmandu
Khimti
Bharatpur Hetauda
Butwal
Duhabi
Dhalkebar
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Basin Transmission Plan
(Courtesy: S.S. Bhat)
90~120 km
Mid hill
trunk
line
Southern
Trunk line
MPP to Trunk Line : 30~40 km
SPP to SPP or MPP: 30~60 km
Mini PP to Mini PP or SPP or MPP : 20~30 km
We are pulling North South lines for each P/S
Mini Pooling Point
Sub Pooling Point
Main Pooling Point
Thank You