Several tidal energy projects operating in Europe and Asia are demonstrating that marine power is no longer an experimental technology but a functioning source of renewable electricity.
In South Korea, the Sihwa Lake Tidal Power Station remains the world's largest tidal power facility. Operating on the country's western coast, the plant has an installed capacity of 254 megawatts generated through 10 submerged turbines integrated into a 12.7-kilometer seawall.
The facility was commissioned in 2011 after the seawall, originally built for flood control and land reclamation, caused environmental problems by restricting seawater circulation. Today, approximately 160 million tons of seawater pass through the turbines daily, generating about 550 gigawatt-hours of electricity annually while helping improve water quality in the lake.
In France, the La Rance Tidal Power Station has been generating electricity since 1966, making it one of the oldest and most successful marine energy projects in the world.
The 240-megawatt facility uses 24 reversible turbines capable of producing electricity during both incoming and outgoing tides. Nearly six decades after entering service, the plant continues to provide power while serving as a benchmark for the durability of marine energy infrastructure.
Scotland has emerged as a center for tidal stream technology, which captures energy directly from moving ocean currents rather than from differences in tidal water levels.
The MeyGen project in the Pentland Firth operates in one of the fastest-flowing tidal channels in the world. Its first phase consists of four 1.5-megawatt turbines anchored directly to the seabed. The project has already supplied more than 80 gigawatt-hours of electricity to the United Kingdom's power grid. One turbine operated for more than six years without requiring major unscheduled maintenance, helping address concerns about the reliability of underwater power systems.
Another Scottish project is taking a different approach.
The Orbital Marine Power O2, operating near the Orkney Islands, uses a floating platform equipped with twin underwater turbines. Unlike conventional seabed-mounted systems, the turbines can be raised above the water surface for maintenance, reducing servicing costs and simplifying repairs. The 2-megawatt installation generates enough electricity to power roughly 2,000 homes.
Meanwhile, Nova Innovation's Shetland Tidal Array in Bluemull Sound has demonstrated the viability of smaller modular systems. The project consists of six seabed-mounted turbines connected through a central subsea hub, allowing electricity from multiple units to be transmitted to shore through a single export cable. The approach reduces infrastructure costs while allowing future expansion.
The success of these projects reflects a broader shift in the marine energy sector.
For decades, ocean energy attracted significant investment but struggled to move beyond the demonstration stage. Many early concepts proved too complex, too expensive or unable to withstand the harsh marine environment for extended periods.
Tidal power has begun to overcome those challenges by focusing on predictable underwater currents and simpler engineering designs. Unlike wind and solar resources, tidal flows are governed by the gravitational interaction between the Earth, moon and sun, making them highly predictable years in advance.
That predictability is becoming increasingly valuable as power grids incorporate larger shares of intermittent renewable energy sources. Grid operators can forecast tidal generation with far greater accuracy than wind or solar output, making it a potentially useful complement to other clean energy technologies.
Industry observers note that the most successful projects share several characteristics: robust construction, simplified mechanical systems and maintenance strategies designed to minimize costly offshore operations.
While wave energy technologies continue to face technical and economic challenges, the growing number of operational tidal facilities suggests that marine energy may finally be establishing itself as a practical contributor to the global renewable energy mix.
