The beginnings of the National Grid was slowly taking shape in 1964 when the Bangsar Power Station was connected to the Connaught Bridge Power Station, with the line subsequently extended to Malacca. By 1965, a plan was set to connect the electricity generating plants that were spread out all over the country. Plants identified to be linked were located at Paka in Terengganu, Temengor, Kenering, Bersia and Batang Padang in Perak, Connaught Bridge, Kapar and Serdang in Selangor, Cameron Highlands in Pahang, Perai in Penang, Port Dickson in Negeri Sembilan, Pergau in Kelantan, Pasir Gudang in Johor and in Malacca. The central area network with Connaught Bridge Power Station in Klang was the precursor of the energy grid; it also tapped into the Cameron Highlands Hydro scheme from the Sultan Yussuf Power Station, and was extended into a western network. Late in the 1980s, the loop was complete when Kota Bharu joined the grid.
Grid description
Transmission system
More than 420 transmission substations in the Peninsular Malaysia, with a total installed capacity of 105,305 MVA, are linked together by approximately 21,000 circuit-kilometers of overhead lines and underground cables operating at 132, 275 and 500 kilovolts. The 500 kV transmission system is the single largest transmission system to be ever developed in Malaysia. Begun in 1994, Phase 1 involved the design and construction of the 500kV overhead lines from Gurun, Kedah in the North along the west coast to Kapar, in the central region and from Pasir Gudang to Yong Peng in the south of Peninsular Malaysia. The total distance covered for the 500 kV transmission lines is 784 circuit-km and the 275 kV portion is 9,257 circuit-km as of February 2017. To cater for the new plant up of generators, namely 3,100 MW Janamanjung Power Plant in the west coast, 372 MW Ulu Jelai Hydro Electric Power Plant in the east coast, and 4,100 MW Tanjung Bin Power Plant in the south, the 500 kV transmission system was extended from Bukit Tarek to Yong Peng via interconnection allows for electricity of Ayer Tawar, Tapah, Bentong South and Lenggeng. The completion of this interconnection allows for electricity transmission to the load centre, which is located in the Klang Valley area of Peninsular Malaysia. A project involving laying a 730 km high-voltage direct current transmission line and a 670 km undersea cable for the 2,400-megawatt Bakun hydroelectric dam has been considered. This may connect all three of Malaysia's electric utility companies with state grids: Tenaga Nasional Berhad, Sarawak Energy Berhad and Sabah Electricity Sdn Bhd. Many of Sabah and Sarawak's generation plants are still not interconnected to a grid.
Power generation capacity connected to the Malaysian National Grid is 22,858 megawatt, with a maximum demand of 17,788 megawatt as of April 2016 according to Suruhanjaya Tenaga. The generation fuel mix in peninsular is 45.55% gas, 50.23% coal, 3.59% hydro and 0.63% from other forms of fuel.
Distribution level
Distribution lines of 66kV, 33 kV, 22 kV, 11 kV, 6.6 kV and 400/230 volt electricity distribution network connect to the National Grid via transmission substations will have their voltages stepped down by transformers.
On 13 January 2005 a power blackout on northern peninsular Malaysia occurred when a transmission line near Serendah, Selangor, had broken down. In response to this, the Central Area Reinforcement project was approved to ensure security of power supply to the Klang Valley.
On 22 April 2008 Sabah had the worst power outage since the commissioning of the east west power grid. Suspected vandals are believed to have removed steel pieces of a 132kV transmission tower that led to its collapse, triggering a major power blackout. An emergency temporary tower was to be built immediately but it also collapsed during construction killing a TNB personnel. On 1 May 2008, another tower collapsed due to missing structural members of the tower that were suspected of being stolen.
