DESPITE its promise, tidal power remains one of the least developed renewable energy technologies in the world. Commercial projects are concentrated in only a handful of countries, while most nations continue to treat tidal energy as an experimental concept rather than a practical source of electricity.
A new study from Ateneo de Manila University suggests the Philippines may be uniquely positioned to change that narrative. Researchers Justin Kyle O. Ricafort and King Harold A. Recto examined the tidal energy potential of three major waterways in the Visayas — the San Bernardino Strait, the San Juanico Strait and the Cebu Strait — concluding that these marine corridors possess characteristics that could support future tidal power generation.
The study, “Assessing Tidal Energy Potential in the Visayas: Viability of the San Bernardino, San Juanico, and Cebu Straits,” comes as the Philippines seeks new renewable energy sources to meet rising demand while reducing dependence on imported fossil fuels.
The research also arrives at a significant moment for the region. Despite years of studies, government initiatives and private-sector announcements, no commercial tidal power facility is currently operating anywhere in Southeast Asia.
An overlooked renewable resource
Most renewable energy discussions in the Philippines focus on solar farms, wind projects, hydropower facilities and geothermal resources. Tidal energy rarely enters the conversation. Yet the country’s geography may make it one of the world’s most favorable locations for the technology.
Unlike continental nations, the country’s more than 7,600 islands are separated by narrow channels and straits. These waterways naturally funnel enormous volumes of seawater as tides rise and fall, accelerating ocean currents in ways that can potentially be harnessed for electricity generation.
The Ateneo researchers focused on tidal stream technology, which captures the kinetic energy of moving water through underwater turbines. Similar to wind turbines, the devices use rotating blades to generate electricity, except they operate beneath the ocean surface.
Because water is more than 800 times denser than air, tidal turbines can generate significant amounts of power even at relatively modest flow speeds. The challenge is finding locations where currents are strong, consistent and economically viable. According to the study, the San Bernardino, San Juanico and Cebu straits emerge as particularly promising candidates.
Why these straits matter
The San Bernardino Strait lies between Southern Luzon and Northern Samar, serving as one of the country’s most important maritime passages. It connects the Philippine Sea to the Samar Sea and experiences powerful tidal currents generated by the movement of large water masses between the Pacific Ocean and inland waters.
The San Juanico Strait, famous for the bridge linking Samar and Leyte, is another narrow channel where tidal flows are concentrated. Meanwhile, the Cebu Strait separates Cebu from neighboring islands and serves as one of the busiest shipping corridors in Central Visayas. These waterways share a common characteristic: geography that naturally constricts and accelerates water movement.
For tidal energy developers, such locations are often more valuable than open coastal waters because stronger currents can translate into greater electricity production. The researchers argue that these sites warrant further investigation as the country explores future marine renewable energy projects.
Predictability
as an advantage
One reason tidal energy continues to attract interest despite its limited deployment is reliability. Solar panels stop generating electricity at night. Wind turbines depend on weather conditions that can change unexpectedly. Tides operate differently.
The rise and fall of ocean waters are governed primarily by gravitational interactions involving the Earth, moon and sun. As a result, tidal patterns can be forecast years or even decades in advance.
For power system operators increasingly concerned about balancing intermittent renewable energy sources, this predictability represents a potentially valuable asset.
“Tidal energy’s predictability distinguishes it from other renewable technologies,” the study notes, highlighting its potential contribution to a more stable energy mix.
The missing industry
Despite these advantages, tidal power remains a niche sector globally. The world’s largest tidal power station, South Korea’s Sihwa Lake facility, began operation in 2011. Several projects operate in the United Kingdom, France and Canada, but global installed tidal capacity remains tiny compared with solar and wind energy.
In Southeast Asia, the industry does not yet exist.Several companies have announced plans for future projects in Philippine and Indonesian waters, including proposals involving the San Bernardino Strait. However, none have reached commercial operation.
This gap between potential and reality reflects the challenges facing the technology. Marine energy systems must withstand harsh underwater environments, including corrosion, strong currents and extreme weather conditions. Installation and maintenance costs can be substantial. Developers must also address concerns involving fisheries, marine biodiversity and navigation.
The Ateneo researchers acknowledge these challenges but argue that the region’s energy needs and geographic advantages justify continued exploration.
A strategic opportunity
For the Philippines, the implications extend beyond renewable energy, already ranks among the world’s leading geothermal producers and has rapidly expanded solar and wind development in recent years. Establishing a tidal energy industry could further diversify the national energy portfolio while creating opportunities for local engineering, manufacturing and maritime industries.
The technology may be particularly relevant for island communities where conventional power generation remains expensive and fuel transportation costs are high. Although commercial deployment remains years away, the study provides an important starting point by identifying locations where future investments and feasibility assessments can be concentrated.
In doing so, it highlights a possibility that has received relatively little attention: the Philippines’ extensive network of straits and channels may represent not only transportation routes connecting islands but also a vast, largely untapped source of renewable energy.
Whether that potential ultimately becomes reality will depend on technological advances, investment decisions and government support. For now, the Ateneo study offers a reminder that some of the country’s most promising energy resources may be flowing quietly beneath the surface of its busiest waterways.
