The country's electricity sector has grown over the past years although not as fast as the leapfrogging increase in demand for power. In the past five years, power production of the state electricity company PT Perusahaan Listrik Negara (PLN) as the power procurement agency totaled 133,109 GWh in 2006, up to 160,786.21 GWh in 2010.
Meanwhile, the country's power requirement has increased 7% a year on the average. Shortages in power supply both in Java and other islands have caused frequent blackouts especially outside Java. The government has taken a big step to cope with the problem by launching crash program building power plants with a total capacity of 10,000 megawatts. The program succeeded in reducing blackouts notably in Java. According to plan, new power plants with a total capacity of 2,400 MW were to be completed in 2010 bringing the additional capacity to 4,300 MW from the coal-fired power plants on stream by that year to be built under the program.
However, PLN and its contractors found difficulties in meeting the target in 2010. Completion of a number of power generating projects were delayed such as PLTU Labuan Units 2, PLTU Rembang (Units 1 and 2), and PLTU Indramayu Units 1.
The country's electricity generation in the country is hampered by problem in supply of fuel especially coal and gas. With the soaring prices of oil, PLN has increased the use of coal and gas as the main fuels. However, gas supply is also a problem although the country is known to be one of the world's largest producers of gas In 2010, there were problems in gas supplies from Kalila to the PLTGU Teluk Lembu, from PGN to PLTGU Muara Tawar and PLTGU Talang Duku, from Pertamina to PLTGU Belawan and from SEMCO to PLTGU Semberah, forcing PLN to use more oil fuels.
In 2010, PLN has a total installed capacity of 26,895 MW. The largest in capacity is from coal-fired power plants (PLTU) with a total capacity of 9,452 MW, followed by steam and gas power plants (PLTGU) contributing 6,951 MW to PLN's total capacity, hydropower plants (PLTA) accounting for 3,523 MW of the total capacity , etc. PLN has 5,541 power generating units with diesel power plant (PLTD) contributing the largest number of 4,637 units or 83.7%, followed by PLTA 381 units (6.9%), PLTG 178 units (3.2%), PLTU 161 units (2.9%) , etc.
With the country's economy expanding 6%-7% annually in the past several years, as against power production growth of only 6.28% new power plants are needed to increase the capacity to prevent shortage in supply that will hamper the economic development. Demand for electricity is expected to grow faster with the economic growth especially industrial growth and growing population.
In the past several years, there are many hurdles delaying implementation of power generating projects notably shortage of gas supply to fuel the facilities. Many power plants after having their fuel converted from oil to gas have to use the expensive oil fuel again.
In a bid to cope with shortage of power supplies, in 2006 the government launched what is called crash program to build coal-fired power plants with a total capacity of 10,000 MW. A number of new power plants were already operational in 2009 under the first program. The rest are to be completed by 2011.
The energy and mineral resources minister has said Indonesia still needs 35,000 MW of electric energy 35.000 MW until 2015. In order to forestall electricity crisis, PLN has launched a program to boost investment in power generating plants using renewable fuel. Independent Power Producer (IPP) is also urged to speed up implementation of their power projects.
Management of electric power systems in Indonesia
In line with the Law no 15/1985, PLN is the authority in the electricity sector. The state company is responsible for the procurement of electricity in the country. Electricity systems in the country are divided into a number of interconnections areas - Java-Bali system, Southern Sumatra systems (Riau, West Sumatra, Jambi, South Sumatra and part of Riau), Northern Sumatra systems (North Sumatra and Aceh). Other areas have no interconnections systems yet.
Java-Bali electricity systems
Java-Bali system is the largest electricity system in Indonesia supporting by a number of large power generating plants and load centers on the islands of Java, Madura and Bali. These systems have a number of power plants with a total capacity of. 22,236 MW connected with extra high voltage transmission lines of up to 500KV and high voltage transmission lines of 150 KV and 70 KV.
Transmission networks having extra high voltage of 500 KV have linked all power plants in Java with transmission networks along the northern coats of the island and are supported by transmission networks in the southern part of the island. The Java-Bali Interconnection system is operated by PLN Penyaluran (distribution) and load regulator center Pusat Pengatur Beban (PLNP3B) Java Bali.
All power plants in Java are put under PLN's subsidiaries - PT Indonesia Power and PT Pembangkit Jawa Bali (PT PJB)
PT. Indonesia Power has 8 power generating business units Suryalaya (3,400 MW), Priok (1,248.08 MW), Semarang (1,469.16 MW), Perak (864.08 MW), Bali (427.63 MW), Kamojang (375 MW), Mrica (306.44 MW), and Saguling (797.35 MW).
The Suralaya business units operate 7 units of coal-fired power plants (PLTU) including Units 1 to 4 each with a capacity 400 MW and units 5 to 7 with a capacity of 600 MW each bringing the total capacity of the business unit to 3,400 MW.
PT Pembangkitan Jawa-Bali (PJB) was established in 1995. PJB has 10 power generating units with installed capacity of 9,007.14 MW and assets valued at Rp 41.5 trillion. It has 2,203 workers. PJB has grown to become a world class electric energy producer in capacity, quality and effectiveness and services that meet the international standards. It units include PLTGU Gresik (2,259.18 MW), Muara Karang (1,208.58 MW), Paiton (800 MW), Paiton Baru (660 MW), Muara Tawar (920 MW), Cirata (1,008 MW), Brantas (281.38 MW), Indramayu (990 MW), Rembang (630 MW) and Pacitan (250 MW).
Sumatra's electric power systems integrated
With the completion of a 150-kV transmission line between Rantau Prapat-Kota Pinang-Bagan Batu 102 km long in July 2007 the electricity systems in northern Sumatra have been connected by a subsystem with the central and southern Sumatra's systems.
The electricity systems of the central-southern Sumatra will supply power up to 70 MW to the northern systems. The central-southern systems have a surplus of around 100 MW at day time.
With the connection between the northern and central-southern systems in Sumatra, the 150 kV high voltage transmission systems (SUTTI) are connected between Bandar Lampung and Banda Aceh, spanning a distance of 3,000 kilometers. The distribution of power in Sumatra, therefore, has improved.
The transmission of power through a 150kV transmission line from Kota Panjang Riau to Kota Pinang Rantau Prapat covers quite a long distance of 400 km. The transmission of the energy is not easy because the distance as the distance has effect on the voltage that when it reaches the northern Sumatra the voltage is only 70kV left.
Therefore, the Sumatra interconnection has not solved all problem of deficit in supply in the northern part of Sumatra.
Electricity systems in other islands
Interconnections in Kalimantan cover Central and South Kalimantan. Connection between South and East Kalimantan is still in the process. In long term target, there will be interconnections between West and East Kalimantan that one region could support other provinces when there is deficit in one region such as because of maintenance or other causes.
The electricity system in West Kalimantan is left behind in development. Currently Pontianak, the provincial city, is building a circular network that if any problem in one transmission line, power could be supplied from other transmission lines in the loop. Similar system is planned for other areas in West Kalimantan before interconnections are built in Kalimantan.
In East Kalimantan, there are a number of electricity systems. The largest is the Mahakam system covering Samarinda, Balikpapan, and Tenggarong, the municipal city of Kutai Kartanegara.
Apart from the Mahakam system, PLN has electricity networks of Bontang-Sangatta in the northern part of that province, the Melak system and Kota Bangun system for area around Kutai Barat and Kutai Kartanegara, and the Petung and Tanah Grogot systems serving customers in southern part of East Kalimantan. The largest the Mahakam system has 330,000 subscribers using 171.5 MW of electric power. The gas and steam powered electric plant of PLTGU Tanjung Batu is one of six power generating plants supporting the Mahakam systems supplying 180 MW for subscribers. Five other power generating units are diesel power plants.
Condition of power generating plants
In the five year period ending in 2010, PLN's installed capacity grew 2% per year on the average. In 2006, PLN's installed capacity totaled 24,846 MW, up to 26,895 MW.
According to the general plan of development of electricity 2010, there will be additional capacity of 6,248 MW from new plants bringing the total installed capacity of PLN to 32,388 MW in 2011.
The largest in capacity in 2010 were PLTU with capacity totaling 9,452 MW, followed by PLTGU 6,952 MW, PLTA 3,523 MW, PLTD 3,268 MW and PLTG 3,224 MW.
Installed capacity of PLN in the Java-Bali systems grew to 18,534.27 MW in 2009. Additional capacity came from the Unit I of PLTU Labuan in Banten with a capacity of 300 MW, the Unit II of PLTU Indramayu in West Java with a capacity of 330 MW.
Meanwhile, in other systems, additional capacity came from a number of new power plants such as in Kalimantan increasing the capacity of the systems outside Java-Bali to 7,102.43 MW in 2009.
Development of power plants
Number of power plants
The number of power generating plants has continued to increase to keep pace with growing requirement. In the five year period ending in 2010, the number of power plants rose from 5,039 units in 2006 to 5,541 units in 2010.
In March 2010, PLTU nit staring operation was PLTU Suralaya with a capacity of 625 MW, followed by the Unit I of PLTU Indramayu and the Unit 2 of PLTU Rembang in June that year. In December, 2010, PLTU Paitons with a capacity of 600 MW and Units 2 and 3 of PLTU Indramayu came on line.
PLTD is the largest in number totaling 4,637 units making up 83.7% of the total number of power generating plants, followed by PLTA totaling 381 units (6.9%), PLTG 178 units (3.2%), PLTU 161 units (2.9%), PLTGU 119 units (2.1%), PLTMG 43 units (0.8%) and PLT Bayu 3 units (0.05%).
Condition of Transmission Systems
The following table shows the capacity of distribution voltage regulators and distribution facility of the Java-Bali system in the past five years.
The capacity of voltage regulators of 70/20 KV has remained almost unchanged as 150 kV transmission networks are used more widely instead of 70 kV transmission networks.
In the past five years the length of 70 kV transmission lines has continued to decline with the replacement with ones of 150 kV which is higher in quality.
The balance in capacity between power plants and Transformer (IBT) and distribution transformers by voltage - 500, 150 and 70 kV in the past five years in shown in the following table.
Transmission and distribution systems outside the Java-Bali interconnections have improved in the past five years notably in Sumatra, Kalimantan, and Sulawesi with the completion of a number of transmission projects. Other systems such as in Nusa Tenggara, Maluku, and Papua, however, have no transmission line yet.
Growth of electric power sector
Production of electricity up 6.28% per year
PLN's production of electricity including from its own power plants and power bought from Independent Power Producer (IPP) grew 6.28% per year on the average in the past five years.
In 2006, power production was recorded at 133,109 GWh, up to 169,786.21 GWh in 2010. The highest growth was recorded in 2010 when power production rose 8.28% from the previous year. Power production from diesel power generators rented to cope with short term problem in shortage of power supply contributed to the increase in power production in 2010.
PLN's program of renting power generators is a short term strategy to meet power requirement in certain areas.
In 2011, there are a number of such steps taken by PLN including renting PLTU from private investors mainly outside Java. PLN provides location coal fuel and transmission lines for the rented PLTU. The private investor provides power generator and operates it. PLN will buy he power produced by the generator.
Sales of electric power up 6.96% per year
Sales of electric power in Indonesia has increased 6.96% a year on the average in the past five years to follow the progress made in the country's economic development..
In 2006, sales totaled 121,609.84 Giga Watt hours (GWh), - up to 147,297 GWh in 2010. The increase followed growing number of subscribers. In 2010, the number of PLN's subscribers rose by 2,317,702 to 42.4 million. The increase in sales was also attributable to improved economic condition.
In the first half of 2011, PLN sets power sales target at 76,867.53 GWh. ...