Indonesia’s blackouts reignite debate over coal-dependent energy transition

JAKARTA — Calls are mounting for Indonesia to accelerate its energy transition after widespread blackouts struck Java and Sumatra in recent weeks, exposing what analysts say are deep vulnerabilities in a power system that remains highly centralized and heavily dependent on coal.

In late May, large parts of Sumatra lost electricity after a transmission line in Jambi failed. Just days later, a separate outage disrupted power across parts of Java, Indonesia’s most populous island and economic center. While officials initially pointed to technical problems, state utility PLN later said constrained coal supplies had contributed to the Java outage.

For energy analysts, the outages underscore a broader structural problem.

“The dependence on a centralized, coal-dominated electricity system is a threat to energy supply security,” said Fabby Tumiwa, executive director of the Institute for Essential Services Reform (IESR).

To reduce the risk of more widespread outages, analysts at the Institute for Energy Economics and Financial Analysis (IEEFA), a U.S.-based think tank, said Indonesia should accelerate the      deployment of decentralized renewable energy, particularly rooftop solar combined with battery energy storage systems (BESS).

“For Indonesia, an archipelago of thousands of islands, rooftop solar combined with battery energy storage systems offers a viable alternative to diesel power, which can be costly and challenging to supply,” IEEFA researchers Mutya Yustika and Randi Bachtiar wrote in a recent analysis.

Unlike fossil fuels, they noted, solar power is not vulnerable to fuel supply disruptions or price volatility. Because rooftop systems can be installed on homes, businesses and industrial facilities, they can also help maintain critical operations when centralized grids fail.

Yet, despite repeated pledges to cut emissions and expand renewable energy, Indonesia’s transition away from fossil fuels has been slow.

Environmental groups say the disconnect is particularly evident on Java, where some of the country’s oldest coal-fired power plants continue operating under policies intended to support the energy transition.

Java remains Indonesia’s coal heartland

Home to around 158 million people, Java is not only the center of Indonesia’s electricity demand but also the country’s largest concentration of coal-fired power generation.

A recent peer-reviewed study published in Total Environment Advances found that the Java-Bali region accounts for 61% of carbon dioxide and fine particulate (PM2.5) emissions from Indonesia’s operating coal fleet. The researchers identified six coal-fired power plants on Java as priority candidates for early retirement because together they generate nearly one-third of the country’s coal-sector CO₂ emissions and PM2.5 pollution. Retiring those six plants could eliminate an estimated 93.5 million metric tons of CO₂ emissions and 33,583 metric tons of PM2.5 emissions annually.

Despite that, environmental groups say government policy continues to extend the operating lives of many aging coal plants through measures such as biomass co-firing and carbon capture and storage (CCS), rather than replacing them with renewable energy.

Indonesia ratified the Paris Agreement in 2016 and has pledged to reach net-zero emissions by 2060 or sooner.

But Fabby of IESR argues that the government is pursuing what he describes as an “energy addition” strategy — adding renewable energy capacity while allowing coal plants to remain online — instead of replacing fossil fuels altogether.

“The government often says that to decarbonize we don’t need to eliminate fossil fuels, but simply use technology so we can continue using our abundant fossil fuel resources,” he said. “So maintaining this infrastructure is still considered necessary by policymakers.”

Government officials acknowledge many of these structural challenges; although, they emphasize different solutions.

Harris, secretary of renewable energy at the Ministry of Energy and Mineral Resources, said electricity demand remains heavily concentrated on Java, accounting for 60-70% of national consumption, while much of the country’s renewable energy potential lies outside the island.

To address that imbalance, he said the government is preparing long-term plans to strengthen inter-island electricity interconnections linking Java with Sumatra and Kalimantan.

For communities living around many of Java’s coal plants, the Indonesian Forum for the Environment (Walhi), the country’s largest environmental group, says that approach has meant continued exposure to air pollution, while new transition policies create additional environmental pressures elsewhere.

Nowhere is that more apparent, the group says, than at the Paiton coal-fired power complex in East Java.

East Java

The Paiton power complex in Probolinggo is among Indonesia’s largest coal-fired power stations and supplies roughly 60% of East Java’s electricity demand.

It is also one of the country’s strongest candidates for early retirement.

The Total Environment Advances study identified Paiton-1 and Paiton-2 among the six highest-priority coal plants for retirement nationwide based on age, carbon emissions, particulate pollution and impacts on surrounding populations. Together with the older PLN-operated unit, the three plants emit nearly 29 million metric tons of CO₂ annually.

Based on those findings, the authors concluded that retiring Paiton would deliver some of Indonesia’s largest reductions in carbon emissions and particulate pollution.

Yet, rather than fully decommissioning the complex, the government seems to be exploring ways to extend its operational life.

Retirement planning for Paiton is underway. The Energy and Mineral Resources Ministry said in 2025 that one long-term option under consideration is converting the site into a nuclear power plant.

In the meantime, the government has begun introducing biomass co-firing. In 2023, Paiton started replacing about 5% of its coal with biomass in several generating units. Officials have said they aim to gradually increase the biomass share, while also studying the use of carbon capture and storage technology to further reduce emissions.

Walhi East Java argues that these measures risk turning the energy transition into a mechanism for extending the life of coal plants rather than replacing them.

“This transforms forests into homogeneous monocultures,” said Pradipta Indra Ariono, director of Walhi East Java.

Compared with natural forests, monoculture energy plantations support far fewer species, store less carbon, and are generally more vulnerable to drought and fire, he said.

Walhi says at least three companies supply sawdust for Paiton’s co-firing program. According to the organization, the companies source biomass from Bondowoso, Situbondo, Jember and Lumajang, where growing demand for wood fuel is increasingly tying local landscapes to the power plant’s supply chain.

The group argues that expansion of biomass production into community forests and social forestry areas could create new ecological and social pressures, while leaving unresolved questions about labor protection, biomass pricing and the environmental impacts of large-scale raw material extraction.

PLN says biomass co-firing at Paiton reduces carbon dioxide emissions by around 471,500 metric tons annually.

Walhi does not dispute that burning biomass reduces coal consumption, but argues that the emissions accounting is incomplete because it focuses only on combustion at the power plant.

Every stage of the biomass supply chain — from clearing land and planting energy crops to harvesting, drying and transporting the fuel — also generates emissions, the organization says.

The group also points to potential air quality impacts.

While biomass replaces a small portion of coal, it still produces particulate pollution. Walhi cites research showing that biomass co-firing can increase emissions of PM10, particles small enough to enter the respiratory system, even when overall emissions remain within Indonesia’s regulatory standards.

Earlier this year, Walhi East Java conducted two weeks of air-quality monitoring in villages surrounding the Paiton complex. The organization said concentrations of PM10 and PM2.5 repeatedly reached unhealthy levels, particularly late at night, with pollution detected as far as 10 kilometers (6 miles) from the power station.

Residents interviewed during the monitoring described recurring respiratory illnesses, while farmers reported coal dust settling on tobacco leaves and reducing crop yields, according to Walhi.

Pradipta said the impacts also extend offshore.

According to Walhi, pollution and coal barge traffic have damaged coral reefs and reduced fish catches, forcing some fishers to travel farther out to sea at higher cost and greater risk.

“Some have eventually stopped fishing altogether, becoming fish pond laborers or daily workers around the power plant,” Pradipta said.

Banten

Walhi says the pattern is not unique to East Java.

In Banten, home to the 4,000-megawatt Suralaya power complex, the organization argues that aging coal plants continue to operate even as they are promoted as part of Indonesia’s energy transition.

The same academic study ranked Suralaya as Indonesia’s highest-priority coal plant for early retirement because of its age, emissions and pollution burden.

The researchers estimated that the complex alone emits more than 28 million metric tons of carbon dioxide annually, making it the country’s largest single source of emissions from coal-fired electricity generation.

Yet, most of the electricity generated at Suralaya is transmitted to Jakarta and West Java, while communities around the plant continue to bear the environmental costs, Walhi said.

The organization said about 41,000 households in Banten still lack adequate electricity access despite the province’s role as one of Indonesia’s largest electricity producers. It also cited concerns over exposure to PM2.5, sulfur dioxide and nitrogen oxides, contamination from fly ash and bottom ash, and declining fish catches linked to thermal discharges into coastal waters.

A 2023 study by the Centre for Research on Energy and Clean Air (CREA) estimated that air pollution from the Suralaya power complex results in an annual loss of 1,470 lives and health-related damages totaling $1.04 billion.

For Walhi, Suralaya illustrates what it describes as an “energy injustice,” in which energy-producing communities shoulder pollution, while much of the electricity is consumed elsewhere.

Walhi says similar concerns are emerging elsewhere on the island.

In Central Java, the organization argues that biomass co-firing risks creating the same land-use conflicts seen around Paiton, while some geothermal developments have also generated environmental disputes.

Rather than opposing renewable energy itself, Walhi says the cases show that projects marketed as clean energy can still create social and ecological costs if they are developed without meaningful community participation.

Harris acknowledged that renewable energy projects have also faced community resistance in several regions, saying the government regards public acceptance as one of the country’s biggest energy-transition challenges.

Calls for change

The blackouts that plunged parts of Java and Sumatra into darkness have added urgency to calls for Indonesia to rethink not only how it generates electricity, but also how the power system is designed.

Following the outages, both IEEFA and IESR urged the government to review regulations that they say have slowed the expansion of rooftop solar.

Current regulations allocate 3,037 megawatts of new rooftop solar capacity through 2034. Household installations also cannot export surplus electricity to the grid, reducing the economic incentive for consumers to install solar panels.

“This combination of high upfront costs and regulatory obstacles has limited household participation in rooftop solar adoption,” Mutya and Randi wrote. “As a result, rooftop solar remains inaccessible to many households despite its potential to improve energy resilience and reduce electricity costs.”

For IEEFA, the recent blackouts illustrate why Indonesia should move away from relying on a small number of large power stations.

Blackouts are more than an inconvenience, the researchers noted. They disrupt hospitals, industries, businesses and public services, with economic losses from major outages estimated to reach trillions of rupiah.

“These impacts highlight the importance of improving system reliability and resilience,” Mutya and Randi wrote.

Fabby said the outages should serve as a reminder that energy transition is not simply about adding more renewable energy to the grid.

Instead, he said, Indonesia needs to gradually replace aging fossil fuel infrastructure with cleaner sources, while making the electricity system more resilient and flexible.

For Walhi, however, the debate extends beyond technology.

The organization argues that replacing coal with renewable energy will not, by itself, create a just transition if new projects continue to shift environmental burdens onto forests, farmland and coastal communities.

That, Walhi says, is precisely what is happening in parts of Java today.

In East Java, communities are being encouraged to grow biomass to keep aging coal plants operating. In Banten, residents living near one of Southeast Asia’s largest coal-fired power complexes continue to bear the health and environmental costs, while much of the electricity generated is transmitted elsewhere.

Rather than viewing the transition simply as a change in fuel, Walhi argues it should also change who benefits from the energy system and who bears its costs.

As Indonesia races to decarbonize its electricity sector, the debate is increasingly shifting from whether the country should transition away from coal to what kind of transition it wants to build and how it will be funded.

Citation

Fadiilah, D., & Dye, A. (2026). Early retirement of coal-fired power plants in Indonesia: A comprehensive analysis of emissions (from Sentinel 5p and HYSPLIT) and population impact. Total Environment Advances, 200145. doi: 10.1016/j.teadva.2026.200145

Banner image: Chimneys of Suralaya coal power plant in Banten loom over a hill where a boy plays. Image by AP Photos/Dita Alangkara.

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Cite this article

Hans Nicholas Jong (2026). Indonesia’s blackouts reignite debate over coal-dependent energy transition. Mongabay Conservation news. DOI: https://doi.org/10.66709/news-322168

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