Enviro News Asia, Jakarta – The intensity of climate-related disasters in Indonesia continues to rise, with National Disaster Management Agency (BNPB) data showing that around 90 percent of disasters in the country over the past five years have been hydrometeorological in nature. The impact is increasingly visible in the national electricity transmission network, where infrastructure damage and power outages have followed in their wake.
In May and June 2025, several regions across Sumatra experienced large-scale power outages. The Institute for Essential Services Reform (IESR) views the incident as a warning that climate change risks to the power system need to be taken seriously to avoid undermining the reliability of an energy supply that underpins economic growth.
IESR Energy System Transformation Director Deon Arinaldo said the resilience of the power system can no longer be measured solely by its ability to deliver reliable and affordable electricity. The system must also withstand physical disruptions caused by extreme weather and climate change.
“We need to drive change in the operation, planning, and management of the power system. Climate change risks must be anticipated, not only for the power system but also for other infrastructure,” Deon said during the first session of IESR’s webinar series on the vulnerability of power assets to climate change impacts, titled “Unpacking the Causes of Sumatra Island’s Blackout.”
TU Delft doctoral candidate Hariadi Aji explained that climate change affects power systems through two main mechanisms: stress and shock. Stress occurs when rising temperatures degrade the performance of power plants and transmission networks, as higher temperatures reduce generation capacity even as electricity demand rises due to increased air conditioning use. Shock, meanwhile, stems from extreme weather events such as floods, landslides, and strong winds that can damage power infrastructure and disrupt the power system.
Hariadi said Indonesia needs to strengthen its grid resilience, the power system’s ability to withstand and recover from climate change impacts. Using an overlay method combining PLN’s power asset data, his research found that rising temperatures reduce generator efficiency, lowering effective generation capacity to around 96 percent, a loss of roughly three to four percent. The largest declines were found in gas-fired power plants, followed by coal-fired plants.
To analyze shock risk, the research combined the locations of power plants, substations, and transmission networks with BNPB’s flood and landslide vulnerability maps. The results showed that most regions across Sumatra, including Aceh, West Sumatra, Bengkulu, Lampung, North Sumatra, Riau, Jambi, and South Sumatra, face a high level of vulnerability to hydrometeorological disasters.
Hariadi said this condition needs to be anticipated through stronger climate-based contingency planning.
“We must ensure energy supply remains reliable, strengthen infrastructure, and build organizational capacity. Operators, regulators, electricity providers, and all stakeholders must be able to anticipate climate change risks and build a more resilient power system,” he said. (*)
