Southeast Asia’s clean energy future may depend as much on governance as technology, with a new report arguing that stronger regional coordination is needed to unlock cross-border subsea power cable projects and accelerate renewable energy integration across ASEAN.

In a report released on June 19, energy think tank Ember said subsea power cables could help connect the region’s unevenly distributed renewable energy resources, improve energy security, lower electricity system costs, and support growing power demand driven by economic growth, electrification, data centers, and artificial intelligence infrastructure.

Despite the technology being commercially proven, Ember said governance challenges remain the main obstacle to wider deployment of cross-border subsea interconnections in Southeast Asia.

“The challenge of cross-border subsea interconnection in ASEAN is increasingly institutional rather than purely technical,” the report said.

According to Ember, Southeast Asia possesses abundant renewable energy resources, but these are concentrated in different locations. Hydropower resources are largely found in the Mekong subregion, while other countries hold significant solar, geothermal, and emerging offshore wind potential.

Subsea power cables could allow these resources to be shared across borders, enabling countries to tap cleaner and potentially lower-cost electricity supplies while strengthening regional energy security.

The report noted that the ASEAN Interconnector Masterplan Study III identified 18 new and existing interconnectors needed to more than double the region’s interconnection capacity from the current 7.7 gigawatts by 2040.

For the Philippines, which already relies on subsea transmission technology to connect major island grids, the findings underscore the potential role of undersea infrastructure in future regional electricity trade.

“The Philippines, for example, has long used HVDC interconnections to link its major island grids, demonstrating that subsea transmission technologies are doable in the region,” Ember said.

The report highlighted the Lao PDR–Thailand–Malaysia–Singapore Power Integration Project (LTMS-PIP) as a milestone for regional electricity trading, showing that multilateral power exchanges are technically feasible and could be expanded through future subsea links.

However, Ember warned that ASEAN’s current planning and regulatory frameworks may not be sufficient for larger and more complex interconnection projects.

The think tank identified three key areas requiring stronger regional coordination: planning and project prioritization, cost allocation and benefit sharing, and maritime governance.

On planning, Ember said ASEAN lacks a dedicated mechanism for continuously evaluating and prioritizing interconnection projects based on regional system needs.

“ASEAN currently lacks a dedicated mechanism for the continuous assessment and prioritisation of cross-border interconnection projects,” the report said.

The group also called for more structured approaches to allocating costs and benefits across participating countries, particularly as future projects become more capital-intensive and involve multiple jurisdictions.

In addition, the report stressed the importance of marine spatial planning as subsea cables compete for space with shipping lanes, fisheries, telecommunications infrastructure, and other maritime activities.

Drawing lessons from Europe, which operates one of the world’s most advanced cross-border electricity interconnection networks, Ember said ASEAN should strengthen existing institutions rather than create entirely new structures.

Among its recommendations are accelerating the operationalization of the ASEAN Power Grid Generation and Transmission Planning (AGTP) function, exploring cross-border cost allocation frameworks, and expanding the role of regional submarine cable coordination mechanisms.

“To unlock the full potential of subsea power cables, ASEAN will need governance frameworks that are both robust and adaptive, capable of coordinating increasingly complex cross-border projects while evolving alongside the region’s energy transition and electricity market needs,” said Alnie Demoral, Energy Analyst at Ember.

Ember added that successful deployment of cross-border subsea power cables could deliver benefits beyond electricity trading, supporting deeper regional cooperation, clean energy investment, and the development of new green industries across Southeast Asia.

“Successfully implemented cross-border subsea power cables could deliver benefits beyond electricity trade,” the report said. “These networks would enable deeper regional cooperation, accelerating clean energy investment and supporting emerging green industries, ultimately reinforcing ASEAN’s transition towards a more resilient and sustainable energy community.”

What do you think? Can stronger regional coordination finally unlock ASEAN’s long-delayed power grid ambitions and accelerate cross-border clean energy trade? Share your insights with the Power Philippines community. 

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