Tidal energy systems harness the power of tidal movements, while wave energy systems capture energy from the surface waves of the ocean.

Both tidal and wave energy systems fall under the category of marine energy, yet they differ significantly in how they capture and convert energy from the ocean. Tidal energy systems utilize the predictable rise and fall of ocean tides. These systems typically involve the construction of tidal barrages, underwater turbines, or tidal lagoons.

A tidal barrage functions like a dam built across the entrance of a coastal basin. As the tide rises, water flows into the basin, and when it is released, it passes through turbines to generate electricity. Underwater turbines operate similarly to wind turbines but are driven by the currents created by tidal movements. Tidal lagoons, a more recent innovation, consist of a circular retaining wall built around a natural basin; these lagoons fill and empty with the tides to facilitate electricity generation.

In contrast, wave energy systems capture energy from the ocean’s surface waves. This is typically achieved through wave energy converters (WECs), which are devices that float on the ocean’s surface and harness the energy derived from wave motion. The energy collected by these devices is subsequently converted into electricity. Some WECs are anchored to the seabed, while others are free-floating. The efficiency of energy capture in wave energy systems largely depends on various factors, including the height, speed, length, and frequency of the waves.

While both tidal and wave energy systems are renewable and possess the potential to provide substantial power, they come with their own sets of advantages and disadvantages. Tidal energy is highly predictable, as tides follow a regular and well-defined cycle. However, suitable locations for tidal power stations are limited, and their construction can have significant environmental impacts. Conversely, wave energy is less predictable but offers a larger potential resource, given that waves are generated across the entire surface of the ocean. Nevertheless, wave energy systems must be designed to endure harsh ocean conditions, and the technology is still in the early stages of development.