Address : KMO Building, Suite 901, Jl. Kyai Maja No. 1, Jakarta Selatan 12120
Phone : (021) 720-2770
Fax : (021) 720-7855
Email :

The Indonesian archipelago comprises of over 17,508 islands. Many of these are uninhabited and many others have no interconnected electricity systems. At present the only islands that are interconnected are Java- Bali and Java – Madura. This interconnected system is referred to by PLN as the ‘Java-Bali’ system. Electricity (and generation) systems on other islands are collectively referred to as the ‘Outer Islands.’

At present an interconnection between Sumatra (the largest island in the archipelago) and Java is under construction and more of this is described at ‘CONNUSA’s Experience at 500 kV’ section.

The transmission voltages on the Java-Bali system are 500 kV and 150 kV. On Sumatra the voltages are 275 kV and 150 kV although 500 kV is now under construction. On the remaining islands the highest voltage is 150 kV.

To coincide with the ‘First 10 000 MW Fast Track Program’ a total of some 1,800 km of overhead lines were due to be constructed. For the ‘Second 10 000 MW Fast Track Program’ this number is expected to approach 3,500 km.

PLN recently published their ’10 Year Long Term Development Plan’. This plan highlights a number of transmission initiatives which can be summarized as follows:

  • Major reinforcements to the existing 500 kV system on Java
  • A 500 kV overhead connection to Bali with onward 500 kV line to Denpasar
  • On Sumatra the introductions of a major East coast 500 kV interconnection from north to south of the Island
  • A 500 kV interconnection between Sumatra and Malaysia
  • Major 275 kV reinforcements to the existing 275 kV system on Sumatra
  • The introduction of 275 kV on the islands of Kalimantan and Sulawesi
  • A 275/150 kV interconnection between Kalimantan and Sarawak
  • Major 150 kV cross country links on the islands of Kalimantan and Sulawesi and localized interconnections on Papua

The very substantial and comprehensive experience of CONNUSA in the Design Engineering and Supervision of Construction for Transmission systems at voltages of 500 kV, 275 kV and 150 kV places the company in a strong and advantageous position to assist PLN in the implementation of the developments described above.


For the past twenty years, CONNUSA in association with international consultants has completed feasibility studies, engineering design, construction supervision and commissioning of:
  • Some 4,200 km of single and double circuit overhead lines
  • Construction of 17 new substations
  • Extensions to 38 existing substations

Full details of CONNUSA’s experience at 500 kV, 275 kV and 150 kV can be found in the following links:

  • Experience at 500 kV
  • Experience at 275 kV
  • Experience at 150 kV


KMO Building, Suite 901,
Jl. Kyai Maja No. 1,
Jakarta Selatan 12120

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Telp : (021) 720-2770
Fax : (021) 720-7855
Email :
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