What You Need to Know About Ocean Wave Energy
Ocean waves represent our planet’s last untapped large-scale renewable energy resource. Water not only makes up over 70% of the surface of our Earth, but the energy contained within waves also has the potential to produce up to 80,000TWh of electricity per year — sufficient to meet our global energy demand five times over.
Ocean Wave Energy Has Tremendous Benefits
Like solar and wind, ocean wave energy is renewable because the ocean is here to stay. Unlike solar and wind power sources, waves are much easier to forecast far in advance. They can produce energy day or night, hot or cold. “Waves are also a steadier, more predictable source of energy than wind or solar power, which need batteries or another form of storage (or backup from fossil power plants), for times when the sun or wind is unavailable.”
When wind passes over the ocean’s surface, it generates waves — a process that often begins hundreds or thousands of miles from shore, making their patterns predictable. Scientists use computer models of wave propagation, allowing us to forecast incoming waves days in advance with accuracy. In comparison with wind or solar energy, it’s much easier to accurately project how much power can be generated, and more importantly, when.
A simple explanation of wave energy can be found here in this short video.
There are Many Types of Ocean Wave Energy Converters (WEC)
Did you know that some of the oldest wave-energy patents date back to the 1790s?
These early approaches provided mechanical energy directly to machinery like sawmills or pumps. Unfortunately, it was difficult to build systems that could survive the ocean’s relentless energy at the time.
However, it was not until much more recently that scientists and engineers have been able to find reliable ways to extract the energy from ocean waves. Today, there are many different mechanical methods for capturing the energy of ocean waves, although the four basic types of WEC are as follows:
1. Oscillating Water Columns were among the first to be developed and deployed into the ocean. Partly submerged in water, the device traps air inside a water-free surface, or ‘column’. When a wave acts on the device, it fills this column with water, emptying as the wave passes. This process compresses the air inside the column, which can then be passed through a turbine to create electrical energy.
2. Point Absorber Systems are buoys that float on the ocean’s surface. The buoy rises and falls with the waves, and this movement is directly used to power an electrical generator. These types of devices can also be some of the most efficient for their size.
3. Oscillating Wave Surge Converters are simple flaps that sit on the ocean floor in shallow water. The wave causes the flap to move back and forth, which drives an electrical generator. These devices can be the simplest, but they only operate in shallow water.
4. Attenuators comprise two floating ‘rafts’ connected with a hinge. Waves move the rafts independently, causing movement at the hinge. This ultimately converts to electricity through a generator. Sir Christopher Cockerell (inventor of the hovercraft) created the original concept.
Wave energy converters (WECs) come in many forms, and it’s our company mission to lead their development. We’re working relentlessly to develop the 1 MW Triton system which fits within the ‘point absorber’ category described above. The Triton offers a new approach to energy capture by using three flexible tendons to connect the reaction structure to the float enabling what we term a multi-mode response.
Our VP of Engineering, Dr. Tim Mundon explains that “Oscilla’s multi-mode architecture allows energy to be captured from the waves in a full six degrees of freedom, allowing Triton to be more efficient and harness more energy than any previous approach.”
Ocean Wave Energy Has A Promising Future
Environmental impact challenges and high costs to date have made adoption of ocean wave energy difficult, however, recent innovations in technology are helping to drive those costs down and the potential way up.
Initially, wave energy solutions will benefit coastal cities, eventually moving further inland as adjustments to the grid are made. It is predicted that early wave energy farming will support 33,000 jobs and meet up to 30% of the US West Coast electricity demand.
Rather than be considered as another renewable energy resource, wave energy may be the key to increasing the adoption of renewables as a whole. In the US, and many countries worldwide, population and electricity demand in coastal areas are growing faster than national averages. In locations such as the US West Coast, wave energy tends to peak when both solar and wind energy is low. Thus combining wave energy with existing wind and solar generation may provide an ideal complement to increase the reliability and consistency of renewable power. A MarketWatch study predicts that ocean energy could grow to a market size of $15bn by 2027.
The future of wave energy is bright and when combined with other renewable energy resources could spell a new era of green living on Earth.
Visit Oscilla Power for more information on wave renewables and the Triton.
Resources
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