Renewable energy is a vibrant and booming industry. One of the lesser-known renewable energy avenues is ocean wave energy harvesting, which harnesses energy from the ocean's natural tides. Harvesting the ocean's forces can be challenging, and scientists are still modifying and testing many designs to do so in a responsible, effective manner. Their goal is to find an ecologically friendly, reliable, and safe solution that's ready for commercialization.
Here, we'll explore several promising ocean wave energy harvesting designs, from underwater-current turbines to the labyrinth of wave energy harvesting designs.
Ocean wave energy harvesting
Wave energy is reliable, consistent, and relatively predictable along coastal regions around the world. It is five times more energy-dense than solar energy and ten times more energy-dense than wind, making it an extremely efficient source of power. In the United States, oceanic power alone could provide up to 3-% of the country's, energy needs.
Daniel Petcovic is the program manager for CorPower Ocean, a company that specializes in wave energy technology. He believes that the potential for wave energy is about four times the global installed nuclear capacity in the world today.
Historically, wave energy research sought to mitigate energy absorbance to protect ships and permanent structures. Therefore, one of the primary challenges of wave energy harvesting technology is to reverse strategic thinking. The goal is to create structures and devices that can harvest wave energy rather than avoid it.
Tidal energy as a renewable source
Tidal energy plants are strategically placed dams that rely on changing ocean tides. These plants produce a gradient for water to flow across electricity-generating turbines. To do so, each plant must be precisely placed in an easily isolated tidal body of water, such as a narrow inlet to a bay or an estuary. Several tidal energy plants around the world have been commercially implemented. The Sihwa Lake Tidal Power Station in South Korea, the largest in the world, produces 254 MW. Unfortunately, massive tidal energy plants come with a significant ecological impact, comparable to damming rivers and streams.
Underwater power turbines for ocean energy harvesting
Like wind turbines, underwater turbines utilize current―in this case, the ocean's current―to spin a motor, which passively generates electricity. Companies like SIMEC Atlantis have tested underwater turbines capable of producing around 1.5 MW of power.
Water has a higher density than air, so equally sized water-based turbines can be significantly smaller than water-based turbines. However, once again, geography will limit the location and implementation of these turbines. To work effectively, underwater turbines must be placed in high-flow areas with quickly moving currents.
The Wonder-Buoy and CorPower Ocean
CorPower Ocean gained attention with a 2016 feature in Wired magazine, where the company displayed its wave energy harvesting device. This device, currently called CorPower C3, is a buoy-shaped Wave Energy Converter. It uses the ocean's oscillation and a controllable tuned resonant amplification apparatus to drive a linear motion device capable of high-efficiency electricity generation across a spectrum of wave periods. Most wave energy harvesting devices achieve a structural efficiency of 1-1.5 MWh/ton, but the C3 is theoretically able to produce five times that efficiency.
Ocean wave energy and the future
Oceanic energy's reliability and consistency make it a desirable source for future renewable energy research and implementation. Today, ocean energy harvesting is at the same stage of development (and profitability) as wind power was in the 1980s, which means it's currently very costly and minimally adopted. However, the race to design a scalable, efficient, productive, and environmentally friendly ocean energy harvesting solution is underway. With successes in research and development, this technology will quickly find its way to global implementation, providing clean, renewable energy to a coastal town near you.
