by Flavia D. Frederick

Introduction 

ASEAN’s energy demand continues to surge alongside its transition toward renewable energy (RE). Yet fossil fuels remain dominant, accounting for over 70% of total supply in 2022. Hydropower leads renewable generation at 19.5%, far surpassing solar and wind. This heavy reliance on water-dependent energy sources creates growing vulnerabilities as climate change intensifies drought conditions, particularly in Mekong countries like Vietnam, Laos, and Cambodia where most major dams operate. With plans to expand regional hydropower capacity, these risks require immediate attention to safeguard energy security. 

The RE landscape is evolving, with solar and wind projects projected to grow by 93% and 70% respectively in the coming years. However, hydropower, solar, and wind are all sensitive to climate extremes. El Niño events regularly trigger droughts across Southeast Asia, with cascading effects on power systems. Vietnam’s 2023 blackouts, caused by plunging hydropower reservoir levels, underscored these risks. Thailand also faced power shortages when reduced river flows curtailed electricity imports from Laos. 

Drought affects more than just hydropower. It disrupts the entire energy system. Thermal power plants lose efficiency due to limited cooling water. Wind generation declines as wind speeds drop. Biomass production suffers from lower crop yields. Solar output also decreases during extreme heat. These combined pressures threaten to slow ASEAN’s energy transition. The situation is worsened by upstream dam  construction in China, which reduces Mekong river flow to downstream countries even during the rainy seasons, intensifying the impact during dry years. With droughts becoming more frequent and severe, ASEAN must diversify its energy sources, improve grid flexibility, and include climate risk in energy planning 

Drought’s Cascading Impacts on ASEAN’s Energy Systems 

Droughts are often driven by the prolonged rainfall shortages and rising temperatures that accelerate evaporation. The 2023-2024 El Niño, for example, brought record heat while reducing hydropower output by 21 TWh compared to 2022, despite 500 MW of new capacity being added. These natural stresses are amplified by deforestation and upstream water management, which further disrupt the water cycle. 

Recent events reveal how quickly droughts can derail energy systems. Vietnam’s 2023 power crisis forced widespread blackouts and industrial shutdowns due to hydropower shortages, costing USD 1.4 billion in lost productivity. Public lighting was cuts in an effort to conserve power. In 2011, Indonesia’s two largest hydropower plants lost 40% of capacity during a drought, resulting in over USD 50 million in losses. In Cambodia, drought in 2019-2020 disrupted 41% of the country’s power generation, forcing the country to adopt coal as a stopgap measure. Laos, facing low Mekong levels, was forced to reduce electricity exports to Thailand by 30%, disrupting regional energy supply chains. 

Some drought trigger compounding impacts. On Indonesia’s Java-Bali grid, reduced hydropower output often coincides with increased lightning activity. Between 2011-2017, 107 lightning incidents damaged critical transmission equipment. This dual threat leaves the system vulnerable to supply and infrastructure failures, pushing utilities to rely more heavily on coal. 

Building Climate-Resilient Energy Pathways 

To adapt to growing climate risks, ASEAN could consider climate-proofing its energy systems. Especially as it advances plans for the ASEAN Power Grid (APG). With key cross-border connections like the Laos-Thailand-Malaysia-Singapore Power Integration Project (LTMS-PIP) and several future links relying heavily on hydropower, drought already limits operations. Thailand, for instance, has scaled back electricity imports, signalling a need for more resilient planning.  

One potential pathway is diversification. Reducing reliance on hydropower may involve scaling up hybrid systems that combine solar, wind, and battery storage. While solar and wind currently account for 4.2% of ASEAN’s electricity generation, experiences from other regions can offer useful insights. For example, in 2023, Brazil where hydropower for supplies 60% of electricity added 36 TWh of wind and solar. In the United States, California deployed 5 GW of battery storage to manage drought-related hydropower losses, stabilizing the grid during peak demand. Though specific approaches may vary depending on national contexts like grid capacity and load profiles, these examples show viable pathways to integrate renewables and boost resilience. 

In addition, integrating climate resilience into grid development could help ensure long-term system stability. As ASEAN invests in cross-border infrastructure, aligning these investments with each member state’s broader decarbonization goals is essential – not only to meet emission reduction targets, but also to avoid stranded assets and ensure system adaptability into a low carbon future. Traditional centralized grids may struggle to accommodate the rising share of VRE and the increasing incidence of climate-induced disruptions. In this context, enhancing grid flexibility will be key to managing variability and ensuring reliability. Technologies like Distributed Energy Resources (DERs) can support this shift. Europe’s Virtual Power Plants  demonstrate how aggregating decentralized assets can improve grid stability, while ASEAN’s emerging initiatives such as Malaysia’s community rooftop solar projects  offer local models to build on.  

Strengthening regional governance may also help address rising transboundary risks. This is particularly relevant in the Mekong region, where upstream developments especially in China, which controls half of the river’s flow have already caused disruptions in downstream countries. Without mechanisms to manage upstream impacts, nations along the river remain vulnerable to sudden changes in water availability, especially during drought. The APG framework could consider including protocols for climate risk management and coordinated responses to water availability. Likewise, cross-border power agreements, particularly those involving hydropower, might incorporate climate-related risks to ensure more equitable and predictable regional cooperation.  

Lastly, reinforcing data and knowledge infrastructure could support more proactive decision-making. ASEAN might consider developing a regional observatory or enhance existing mechanisms to monitor climate and energy data, improving drought forecasting and early response. Strategic investments in research and development could prioritize drought-resilient technologies and robust data systems that promote effective knowledge sharing across the region. 

Conclusion:  

The recurring droughts across ASEAN serve as a wake-up call, not to abandon the clean energy transition, but to rethink and strengthen it. From Vietnam’s blackouts to Laos’ export cuts, the region’s energy systems are already under climate stress. As climate extremes become more frequent and severe, the risks to energy security will only grow. Rather than slowing the transition to clean energy, these shocks should accelerate efforts to diversity the energy mix and strengthen mechanisms for climate adaptation such as accounting for water variability, improving drought forecasting, and building more flexible grids. ASEAN’s sustainable future depends on building smarter, stronger systems that can deliver power even through the dry seasons.