Operators work on a high voltage tower in Jakarta, Indonesia, July 27, 2019. Photo: AFP via NurPhoto/ Andrew Gal

An August 4 power blackout across Indonesia’s West Java has raised new questions about why state-run utility Perusahaan Listrik Negara (PLN) continues to build new stations instead of upgrading the transmission network on the 28,400-megawatt (MW) Java-Bali grid.

Former PLN executives are also questioning whether over-stocking the company with moneymen and reducing the utility’s maintenance budget by an annual 10% over the past five years has been an advisable policy for such a strategic industry.

Bound by government pricing dictates and other problems, the cash-strapped state company may have been hit by a perfect storm on what started out as a quiet Sunday morning when several stations were reportedly off line and one of four circuits carrying power from East Java was under maintenance.

A disruption to one of the two circuits on the northern east-west transmission line in Central Java triggered a cascading series of system failures which affected almost every power station across West Java, but most crucially the 4,000MW coal-fired Suralaya complex on the northwest coast.

Jakarta lost all its power, stalling the newly-opened mass rail transit system, which is still without back-up facilities, and shutting down the Internet, television stations and phone services for up to 18 hours in some areas of the capital and surrounding West Java.

The additional loss of mobile banking, cashless payments and app-based transportation may have undermined public confidence in the government’s current drive to introduce “Industry 4.0”, which aims to fuse digitalization with traditional industrial processes.

Looking for answers that may not be known definitively for another two months, a stony-faced President Joko Widodo stalked into the PLN head office the morning after the blackout and told acting president-director Sripeni Inten Cahyani: “Please don’t let this happen again. Ever.”

President Joko Widodo made a house call to PLN after the August 4 blackout. Photo: Pinterest

Cayhani, an accountant, was unable to provide any satisfactory answers to the president’s questions, in particular why there did not appear to be any contingency planning that under normal circumstances should have quickly isolated the transmission problem.

The problems could run deeper. Former PLN chief executive Sofyan Basir, 61, was forced to resign last April after he was indicted in a corruption case linked to a US$900 million coal-fired power station in Sumatra, which has also implicated a former minister and a senior Golkar Party politician.

A similar transmission glitch near the West Java city of Cilegon in August 2005 tripped the six generating units at Suralaya and two of the eight units at the giant Paiton complex in East Java, which caused a seven-hour outage across most parts of Java and Bali.

Back then, however, PLN was engaged in a delicate balancing act, curtailing supply to industry and refusing new connections to private homes in a losing effort to maintain a tiny reserve on a grid that then had an installed capacity of only 18,500MW.

The previous major outage was in 1997, again because of a disruption in the 500 kilovolt (KV) high-voltage line from the Suralaya facility, which opened its first two units in 1984. In that case, PLN engineers managed to minimize the impact and keep some of the power plants on line.

Police claim the latest transmission failure may have been due to tall trees coming into contact with the high voltage 500KV line, but that would suggest PLN had allowed them to grow beyond the permitted clearance of nine meters.

Workers assemble cables at an extra-high voltage tower in Jakarta, February 16, 2018. Photo: NurPhoto via AFP Forum/Aditya Irawan

Even then, a short circuit should have been brief and had only a small impact relative to the electricity flowing in the greater network. Normal system protection should also have detected the short and tripped the nearest sub-station, south of the Central Java province capital of Semarang.

Experts are puzzled why staffers at the utility’s Gandul nerve center in south Jakarta, once known as the best and the brightest, were unable to head off the cascade effect. Transmission disruptions are not that uncommon, they say, but a total network failure is.

Protection protocols are a final defense against cascading events, with frequency load-shedding and voltage-load shedding techniques being brought into play to maintain the flow of power through the rest of the network during a major disturbance.

That means carefully bleeding off portions of the load from the system until a balance is reached between demand and generation; if the deficit persists, then the same protective measures must be tried again to achieve the required result.

As it was, the second circuit on the northern line was overwhelmed and with PLN carrying out maintenance on one of the two circuits on Java’s southern line, that too became overloaded and cut off all power from Paitan and Gresik, the two major stations in East Java.

With the load in the western network dropping below critical levels, and North Jakarta’s gas-fired Muara Tawar and Muara Karang stations, which constitute the so-called spinning reserve, both off-line as part of cost-saving measures, the power supply to 30 million customers collapsed.

The nation’s second largest state company in asset value, PLN has not only been under pressure to cut costs but also to get out of the capital-intensive generating business and focus on its main mission of supplying electricity to Indonesia’s far-flung population.

In 2000, newly-appointed PLN president director Kuntoro Mangkusubroto, a former mines and energy minister, had sought to formalize a policy, tentatively introduced during the Suharto era, in which PLN would concentrate on transmission and distribution and leave generation to private developers.

But although private companies are constitutionally forbidden from electricity distribution, Kuntoro was forced to abandon the initiative in the face of demonstrations by the 50,000-strong PLN workers union, fearful that such a move would lead to widespread layoffs.

Only three years ago, the Mines and Energy Ministry’s director-general for electricity and energy utilization, Jarman, told a national power congress: “In the years to come PLN should focus on transmission and distribution while leaving generation to developers.”

Under a 2015 regulation, independent private producers were to meet 25,000MW of Widodo’s 35,000MW expansion program. To no-one’s surprise, the program proved to be overly ambitious on all counts, currently reaching only 10% of its target.

A woman uses an oil lamp at her home without electricity in Pliken village, Pekalongan, Central Java, Indonesia, March 10, 2016. Photo AFP Forum via NurPhoto/Pradita Utana

Western investors and financial institutions no longer want to touch coal, which along with other fossil fuels still makes up about 80% of the nation’s energy mix and, to the concern of environmentalists, could go even higher over the next decade.

Moreover, Widodo has been reluctant to raise tariffs in an election year and the Ministry of Finance wants to contain subsidies; with the PLN balance sheet in disrepair, demands from independent producers for government guarantees have fallen on deaf ears.

Mines and Energy Minister Ignasius Jonan has already warned that Indonesia is unlikely to reach the target of renewables making up 23% of the energy mix by 2025, as set down after signing the 2015 Paris climate change agreement.

Last year, Indonesia launched two wind-power projects amounting to 145MW in Sulawesi, but even then renewables in the form of geothermal and hydro contribute to only 13% of electricity generation and there are few other such projects in the pipeline.

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